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-rw-r--r--fs/Kconfig7
-rw-r--r--fs/Makefile2
-rw-r--r--fs/afs/internal.h9
-rw-r--r--fs/afs/mntpt.c149
-rw-r--r--fs/afs/super.c430
-rw-r--r--fs/afs/volume.c4
-rw-r--r--fs/filesystems.c4
-rw-r--r--fs/fs_context.c642
-rw-r--r--fs/fs_parser.c447
-rw-r--r--fs/hugetlbfs/inode.c358
-rw-r--r--fs/internal.h13
-rw-r--r--fs/kernfs/kernfs-internal.h1
-rw-r--r--fs/kernfs/mount.c119
-rw-r--r--fs/mount.h5
-rw-r--r--fs/namei.c4
-rw-r--r--fs/namespace.c395
-rw-r--r--fs/pnode.c5
-rw-r--r--fs/pnode.h3
-rw-r--r--fs/proc/inode.c52
-rw-r--r--fs/proc/internal.h5
-rw-r--r--fs/proc/root.c236
-rw-r--r--fs/super.c344
-rw-r--r--fs/sysfs/mount.c73
23 files changed, 2421 insertions, 886 deletions
diff --git a/fs/Kconfig b/fs/Kconfig
index 2557506051a3..3e6d3101f3ff 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -8,6 +8,13 @@ menu "File systems"
config DCACHE_WORD_ACCESS
bool
+config VALIDATE_FS_PARSER
+ bool "Validate filesystem parameter description"
+ default y
+ help
+ Enable this to perform validation of the parameter description for a
+ filesystem when it is registered.
+
if BLOCK
config FS_IOMAP
diff --git a/fs/Makefile b/fs/Makefile
index 7bff9abecfa4..427fec226fae 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -13,7 +13,7 @@ obj-y := open.o read_write.o file_table.o super.o \
seq_file.o xattr.o libfs.o fs-writeback.o \
pnode.o splice.o sync.o utimes.o d_path.o \
stack.o fs_struct.o statfs.o fs_pin.o nsfs.o \
- fs_types.o
+ fs_types.o fs_context.o fs_parser.o
ifeq ($(CONFIG_BLOCK),y)
obj-y += buffer.o block_dev.o direct-io.o mpage.o
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 8871b9e8645f..bb1f244b2b3a 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -36,15 +36,14 @@
struct pagevec;
struct afs_call;
-struct afs_mount_params {
- bool rwpath; /* T if the parent should be considered R/W */
+struct afs_fs_context {
bool force; /* T to force cell type */
bool autocell; /* T if set auto mount operation */
bool dyn_root; /* T if dynamic root */
+ bool no_cell; /* T if the source is "none" (for dynroot) */
afs_voltype_t type; /* type of volume requested */
- int volnamesz; /* size of volume name */
+ unsigned int volnamesz; /* size of volume name */
const char *volname; /* name of volume to mount */
- struct net *net_ns; /* Network namespace in effect */
struct afs_net *net; /* the AFS net namespace stuff */
struct afs_cell *cell; /* cell in which to find volume */
struct afs_volume *volume; /* volume record */
@@ -1274,7 +1273,7 @@ static inline struct afs_volume *__afs_get_volume(struct afs_volume *volume)
return volume;
}
-extern struct afs_volume *afs_create_volume(struct afs_mount_params *);
+extern struct afs_volume *afs_create_volume(struct afs_fs_context *);
extern void afs_activate_volume(struct afs_volume *);
extern void afs_deactivate_volume(struct afs_volume *);
extern void afs_put_volume(struct afs_cell *, struct afs_volume *);
diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index 2e51c6994148..eecd8b699186 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -17,6 +17,7 @@
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/gfp.h>
+#include <linux/fs_context.h>
#include "internal.h"
@@ -47,6 +48,8 @@ static DECLARE_DELAYED_WORK(afs_mntpt_expiry_timer, afs_mntpt_expiry_timed_out);
static unsigned long afs_mntpt_expiry_timeout = 10 * 60;
+static const char afs_root_volume[] = "root.cell";
+
/*
* no valid lookup procedure on this sort of dir
*/
@@ -68,108 +71,112 @@ static int afs_mntpt_open(struct inode *inode, struct file *file)
}
/*
- * create a vfsmount to be automounted
+ * Set the parameters for the proposed superblock.
*/
-static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
+static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt)
{
- struct afs_super_info *as;
- struct vfsmount *mnt;
- struct afs_vnode *vnode;
- struct page *page;
- char *devname, *options;
- bool rwpath = false;
+ struct afs_fs_context *ctx = fc->fs_private;
+ struct afs_super_info *src_as = AFS_FS_S(mntpt->d_sb);
+ struct afs_vnode *vnode = AFS_FS_I(d_inode(mntpt));
+ struct afs_cell *cell;
+ const char *p;
int ret;
- _enter("{%pd}", mntpt);
-
- BUG_ON(!d_inode(mntpt));
-
- ret = -ENOMEM;
- devname = (char *) get_zeroed_page(GFP_KERNEL);
- if (!devname)
- goto error_no_devname;
-
- options = (char *) get_zeroed_page(GFP_KERNEL);
- if (!options)
- goto error_no_options;
+ if (fc->net_ns != src_as->net_ns) {
+ put_net(fc->net_ns);
+ fc->net_ns = get_net(src_as->net_ns);
+ }
- vnode = AFS_FS_I(d_inode(mntpt));
+ if (src_as->volume && src_as->volume->type == AFSVL_RWVOL) {
+ ctx->type = AFSVL_RWVOL;
+ ctx->force = true;
+ }
+ if (ctx->cell) {
+ afs_put_cell(ctx->net, ctx->cell);
+ ctx->cell = NULL;
+ }
if (test_bit(AFS_VNODE_PSEUDODIR, &vnode->flags)) {
/* if the directory is a pseudo directory, use the d_name */
- static const char afs_root_cell[] = ":root.cell.";
unsigned size = mntpt->d_name.len;
- ret = -ENOENT;
- if (size < 2 || size > AFS_MAXCELLNAME)
- goto error_no_page;
+ if (size < 2)
+ return -ENOENT;
+ p = mntpt->d_name.name;
if (mntpt->d_name.name[0] == '.') {
- devname[0] = '%';
- memcpy(devname + 1, mntpt->d_name.name + 1, size - 1);
- memcpy(devname + size, afs_root_cell,
- sizeof(afs_root_cell));
- rwpath = true;
- } else {
- devname[0] = '#';
- memcpy(devname + 1, mntpt->d_name.name, size);
- memcpy(devname + size + 1, afs_root_cell,
- sizeof(afs_root_cell));
+ size--;
+ p++;
+ ctx->type = AFSVL_RWVOL;
+ ctx->force = true;
}
+ if (size > AFS_MAXCELLNAME)
+ return -ENAMETOOLONG;
+
+ cell = afs_lookup_cell(ctx->net, p, size, NULL, false);
+ if (IS_ERR(cell)) {
+ pr_err("kAFS: unable to lookup cell '%pd'\n", mntpt);
+ return PTR_ERR(cell);
+ }
+ ctx->cell = cell;
+
+ ctx->volname = afs_root_volume;
+ ctx->volnamesz = sizeof(afs_root_volume) - 1;
} else {
/* read the contents of the AFS special symlink */
+ struct page *page;
loff_t size = i_size_read(d_inode(mntpt));
char *buf;
- ret = -EINVAL;
+ if (src_as->cell)
+ ctx->cell = afs_get_cell(src_as->cell);
+
if (size > PAGE_SIZE - 1)
- goto error_no_page;
+ return -EINVAL;
page = read_mapping_page(d_inode(mntpt)->i_mapping, 0, NULL);
- if (IS_ERR(page)) {
- ret = PTR_ERR(page);
- goto error_no_page;
- }
+ if (IS_ERR(page))
+ return PTR_ERR(page);
if (PageError(page)) {
ret = afs_bad(AFS_FS_I(d_inode(mntpt)), afs_file_error_mntpt);
- goto error;
+ put_page(page);
+ return ret;
}
- buf = kmap_atomic(page);
- memcpy(devname, buf, size);
- kunmap_atomic(buf);
+ buf = kmap(page);
+ ret = vfs_parse_fs_string(fc, "source", buf, size);
+ kunmap(page);
put_page(page);
- page = NULL;
+ if (ret < 0)
+ return ret;
}
- /* work out what options we want */
- as = AFS_FS_S(mntpt->d_sb);
- if (as->cell) {
- memcpy(options, "cell=", 5);
- strcpy(options + 5, as->cell->name);
- if ((as->volume && as->volume->type == AFSVL_RWVOL) || rwpath)
- strcat(options, ",rwpath");
- }
+ return 0;
+}
- /* try and do the mount */
- _debug("--- attempting mount %s -o %s ---", devname, options);
- mnt = vfs_submount(mntpt, &afs_fs_type, devname, options);
- _debug("--- mount result %p ---", mnt);
+/*
+ * create a vfsmount to be automounted
+ */
+static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
+{
+ struct fs_context *fc;
+ struct vfsmount *mnt;
+ int ret;
- free_page((unsigned long) devname);
- free_page((unsigned long) options);
- _leave(" = %p", mnt);
- return mnt;
+ BUG_ON(!d_inode(mntpt));
-error:
- put_page(page);
-error_no_page:
- free_page((unsigned long) options);
-error_no_options:
- free_page((unsigned long) devname);
-error_no_devname:
- _leave(" = %d", ret);
- return ERR_PTR(ret);
+ fc = fs_context_for_submount(&afs_fs_type, mntpt);
+ if (IS_ERR(fc))
+ return ERR_CAST(fc);
+
+ ret = afs_mntpt_set_params(fc, mntpt);
+ if (!ret)
+ mnt = fc_mount(fc);
+ else
+ mnt = ERR_PTR(ret);
+
+ put_fs_context(fc);
+ return mnt;
}
/*
diff --git a/fs/afs/super.c b/fs/afs/super.c
index e684f6769b15..5adf012b8e27 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -1,6 +1,6 @@
/* AFS superblock handling
*
- * Copyright (c) 2002, 2007 Red Hat, Inc. All rights reserved.
+ * Copyright (c) 2002, 2007, 2018 Red Hat, Inc. All rights reserved.
*
* This software may be freely redistributed under the terms of the
* GNU General Public License.
@@ -21,7 +21,7 @@
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
-#include <linux/parser.h>
+#include <linux/fs_parser.h>
#include <linux/statfs.h>
#include <linux/sched.h>
#include <linux/nsproxy.h>
@@ -30,21 +30,22 @@
#include "internal.h"
static void afs_i_init_once(void *foo);
-static struct dentry *afs_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data);
static void afs_kill_super(struct super_block *sb);
static struct inode *afs_alloc_inode(struct super_block *sb);
static void afs_destroy_inode(struct inode *inode);
static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
static int afs_show_devname(struct seq_file *m, struct dentry *root);
static int afs_show_options(struct seq_file *m, struct dentry *root);
+static int afs_init_fs_context(struct fs_context *fc);
+static const struct fs_parameter_description afs_fs_parameters;
struct file_system_type afs_fs_type = {
- .owner = THIS_MODULE,
- .name = "afs",
- .mount = afs_mount,
- .kill_sb = afs_kill_super,
- .fs_flags = 0,
+ .owner = THIS_MODULE,
+ .name = "afs",
+ .init_fs_context = afs_init_fs_context,
+ .parameters = &afs_fs_parameters,
+ .kill_sb = afs_kill_super,
+ .fs_flags = 0,
};
MODULE_ALIAS_FS("afs");
@@ -63,22 +64,22 @@ static const struct super_operations afs_super_ops = {
static struct kmem_cache *afs_inode_cachep;
static atomic_t afs_count_active_inodes;
-enum {
- afs_no_opt,
- afs_opt_cell,
- afs_opt_dyn,
- afs_opt_rwpath,
- afs_opt_vol,
- afs_opt_autocell,
+enum afs_param {
+ Opt_autocell,
+ Opt_dyn,
+ Opt_source,
};
-static const match_table_t afs_options_list = {
- { afs_opt_cell, "cell=%s" },
- { afs_opt_dyn, "dyn" },
- { afs_opt_rwpath, "rwpath" },
- { afs_opt_vol, "vol=%s" },
- { afs_opt_autocell, "autocell" },
- { afs_no_opt, NULL },
+static const struct fs_parameter_spec afs_param_specs[] = {
+ fsparam_flag ("autocell", Opt_autocell),
+ fsparam_flag ("dyn", Opt_dyn),
+ fsparam_string("source", Opt_source),
+ {}
+};
+
+static const struct fs_parameter_description afs_fs_parameters = {
+ .name = "kAFS",
+ .specs = afs_param_specs,
};
/*
@@ -190,84 +191,23 @@ static int afs_show_options(struct seq_file *m, struct dentry *root)
}
/*
- * parse the mount options
- * - this function has been shamelessly adapted from the ext3 fs which
- * shamelessly adapted it from the msdos fs
- */
-static int afs_parse_options(struct afs_mount_params *params,
- char *options, const char **devname)
-{
- struct afs_cell *cell;
- substring_t args[MAX_OPT_ARGS];
- char *p;
- int token;
-
- _enter("%s", options);
-
- options[PAGE_SIZE - 1] = 0;
-
- while ((p = strsep(&options, ","))) {
- if (!*p)
- continue;
-
- token = match_token(p, afs_options_list, args);
- switch (token) {
- case afs_opt_cell:
- rcu_read_lock();
- cell = afs_lookup_cell_rcu(params->net,
- args[0].from,
- args[0].to - args[0].from);
- rcu_read_unlock();
- if (IS_ERR(cell))
- return PTR_ERR(cell);
- afs_put_cell(params->net, params->cell);
- params->cell = cell;
- break;
-
- case afs_opt_rwpath:
- params->rwpath = true;
- break;
-
- case afs_opt_vol:
- *devname = args[0].from;
- break;
-
- case afs_opt_autocell:
- params->autocell = true;
- break;
-
- case afs_opt_dyn:
- params->dyn_root = true;
- break;
-
- default:
- printk(KERN_ERR "kAFS:"
- " Unknown or invalid mount option: '%s'\n", p);
- return -EINVAL;
- }
- }
-
- _leave(" = 0");
- return 0;
-}
-
-/*
- * parse a device name to get cell name, volume name, volume type and R/W
- * selector
- * - this can be one of the following:
+ * Parse the source name to get cell name, volume name, volume type and R/W
+ * selector.
+ *
+ * This can be one of the following:
* "%[cell:]volume[.]" R/W volume
- * "#[cell:]volume[.]" R/O or R/W volume (rwpath=0),
- * or R/W (rwpath=1) volume
+ * "#[cell:]volume[.]" R/O or R/W volume (R/O parent),
+ * or R/W (R/W parent) volume
* "%[cell:]volume.readonly" R/O volume
* "#[cell:]volume.readonly" R/O volume
* "%[cell:]volume.backup" Backup volume
* "#[cell:]volume.backup" Backup volume
*/
-static int afs_parse_device_name(struct afs_mount_params *params,
- const char *name)
+static int afs_parse_source(struct fs_context *fc, struct fs_parameter *param)
{
+ struct afs_fs_context *ctx = fc->fs_private;
struct afs_cell *cell;
- const char *cellname, *suffix;
+ const char *cellname, *suffix, *name = param->string;
int cellnamesz;
_enter(",%s", name);
@@ -278,69 +218,149 @@ static int afs_parse_device_name(struct afs_mount_params *params,
}
if ((name[0] != '%' && name[0] != '#') || !name[1]) {
+ /* To use dynroot, we don't want to have to provide a source */
+ if (strcmp(name, "none") == 0) {
+ ctx->no_cell = true;
+ return 0;
+ }
printk(KERN_ERR "kAFS: unparsable volume name\n");
return -EINVAL;
}
/* determine the type of volume we're looking for */
- params->type = AFSVL_ROVOL;
- params->force = false;
- if (params->rwpath || name[0] == '%') {
- params->type = AFSVL_RWVOL;
- params->force = true;
+ if (name[0] == '%') {
+ ctx->type = AFSVL_RWVOL;
+ ctx->force = true;
}
name++;
/* split the cell name out if there is one */
- params->volname = strchr(name, ':');
- if (params->volname) {
+ ctx->volname = strchr(name, ':');
+ if (ctx->volname) {
cellname = name;
- cellnamesz = params->volname - name;
- params->volname++;
+ cellnamesz = ctx->volname - name;
+ ctx->volname++;
} else {
- params->volname = name;
+ ctx->volname = name;
cellname = NULL;
cellnamesz = 0;
}
/* the volume type is further affected by a possible suffix */
- suffix = strrchr(params->volname, '.');
+ suffix = strrchr(ctx->volname, '.');
if (suffix) {
if (strcmp(suffix, ".readonly") == 0) {
- params->type = AFSVL_ROVOL;
- params->force = true;
+ ctx->type = AFSVL_ROVOL;
+ ctx->force = true;
} else if (strcmp(suffix, ".backup") == 0) {
- params->type = AFSVL_BACKVOL;
- params->force = true;
+ ctx->type = AFSVL_BACKVOL;
+ ctx->force = true;
} else if (suffix[1] == 0) {
} else {
suffix = NULL;
}
}
- params->volnamesz = suffix ?
- suffix - params->volname : strlen(params->volname);
+ ctx->volnamesz = suffix ?
+ suffix - ctx->volname : strlen(ctx->volname);
_debug("cell %*.*s [%p]",
- cellnamesz, cellnamesz, cellname ?: "", params->cell);
+ cellnamesz, cellnamesz, cellname ?: "", ctx->cell);
/* lookup the cell record */
- if (cellname || !params->cell) {
- cell = afs_lookup_cell(params->net, cellname, cellnamesz,
+ if (cellname) {
+ cell = afs_lookup_cell(ctx->net, cellname, cellnamesz,
NULL, false);
if (IS_ERR(cell)) {
- printk(KERN_ERR "kAFS: unable to lookup cell '%*.*s'\n",
+ pr_err("kAFS: unable to lookup cell '%*.*s'\n",
cellnamesz, cellnamesz, cellname ?: "");
return PTR_ERR(cell);
}
- afs_put_cell(params->net, params->cell);
- params->cell = cell;
+ afs_put_cell(ctx->net, ctx->cell);
+ ctx->cell = cell;
}
_debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
- params->cell->name, params->cell,
- params->volnamesz, params->volnamesz, params->volname,
- suffix ?: "-", params->type, params->force ? " FORCE" : "");
+ ctx->cell->name, ctx->cell,
+ ctx->volnamesz, ctx->volnamesz, ctx->volname,
+ suffix ?: "-", ctx->type, ctx->force ? " FORCE" : "");
+
+ fc->source = param->string;
+ param->string = NULL;
+ return 0;
+}
+
+/*
+ * Parse a single mount parameter.
+ */
+static int afs_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+ struct fs_parse_result result;
+ struct afs_fs_context *ctx = fc->fs_private;
+ int opt;
+
+ opt = fs_parse(fc, &afs_fs_parameters, param, &result);
+ if (opt < 0)
+ return opt;
+
+ switch (opt) {
+ case Opt_source:
+ return afs_parse_source(fc, param);
+
+ case Opt_autocell:
+ ctx->autocell = true;
+ break;
+
+ case Opt_dyn:
+ ctx->dyn_root = true;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ _leave(" = 0");
+ return 0;
+}
+
+/*
+ * Validate the options, get the cell key and look up the volume.
+ */
+static int afs_validate_fc(struct fs_context *fc)
+{
+ struct afs_fs_context *ctx = fc->fs_private;
+ struct afs_volume *volume;
+ struct key *key;
+
+ if (!ctx->dyn_root) {
+ if (ctx->no_cell) {
+ pr_warn("kAFS: Can only specify source 'none' with -o dyn\n");
+ return -EINVAL;
+ }
+
+ if (!ctx->cell) {
+ pr_warn("kAFS: No cell specified\n");
+ return -EDESTADDRREQ;
+ }
+
+ /* We try to do the mount securely. */
+ key = afs_request_key(ctx->cell);
+ if (IS_ERR(key))
+ return PTR_ERR(key);
+
+ ctx->key = key;
+
+ if (ctx->volume) {
+ afs_put_volume(ctx->cell, ctx->volume);
+ ctx->volume = NULL;
+ }
+
+ volume = afs_create_volume(ctx);
+ if (IS_ERR(volume))
+ return PTR_ERR(volume);
+
+ ctx->volume = volume;
+ }
return 0;
}
@@ -348,39 +368,34 @@ static int afs_parse_device_name(struct afs_mount_params *params,
/*
* check a superblock to see if it's the one we're looking for
*/
-static int afs_test_super(struct super_block *sb, void *data)
+static int afs_test_super(struct super_block *sb, struct fs_context *fc)
{
- struct afs_super_info *as1 = data;
+ struct afs_fs_context *ctx = fc->fs_private;
struct afs_super_info *as = AFS_FS_S(sb);
- return (as->net_ns == as1->net_ns &&
+ return (as->net_ns == fc->net_ns &&
as->volume &&
- as->volume->vid == as1->volume->vid &&
+ as->volume->vid == ctx->volume->vid &&
!as->dyn_root);
}
-static int afs_dynroot_test_super(struct super_block *sb, void *data)
+static int afs_dynroot_test_super(struct super_block *sb, struct fs_context *fc)
{
- struct afs_super_info *as1 = data;
struct afs_super_info *as = AFS_FS_S(sb);
- return (as->net_ns == as1->net_ns &&
+ return (as->net_ns == fc->net_ns &&
as->dyn_root);
}
-static int afs_set_super(struct super_block *sb, void *data)
+static int afs_set_super(struct super_block *sb, struct fs_context *fc)
{
- struct afs_super_info *as = data;
-
- sb->s_fs_info = as;
return set_anon_super(sb, NULL);
}
/*
* fill in the superblock
*/
-static int afs_fill_super(struct super_block *sb,
- struct afs_mount_params *params)
+static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
{
struct afs_super_info *as = AFS_FS_S(sb);
struct afs_fid fid;
@@ -412,13 +427,13 @@ static int afs_fill_super(struct super_block *sb,
fid.vnode = 1;
fid.vnode_hi = 0;
fid.unique = 1;
- inode = afs_iget(sb, params->key, &fid, NULL, NULL, NULL);
+ inode = afs_iget(sb, ctx->key, &fid, NULL, NULL, NULL);
}
if (IS_ERR(inode))
return PTR_ERR(inode);
- if (params->autocell || params->dyn_root)
+ if (ctx->autocell || as->dyn_root)
set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
ret = -ENOMEM;
@@ -443,17 +458,20 @@ error:
return ret;
}
-static struct afs_super_info *afs_alloc_sbi(struct afs_mount_params *params)
+static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc)
{
+ struct afs_fs_context *ctx = fc->fs_private;
struct afs_super_info *as;
as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
if (as) {
- as->net_ns = get_net(params->net_ns);
- if (params->dyn_root)
+ as->net_ns = get_net(fc->net_ns);
+ if (ctx->dyn_root) {
as->dyn_root = true;
- else
- as->cell = afs_get_cell(params->cell);
+ } else {
+ as->cell = afs_get_cell(ctx->cell);
+ as->volume = __afs_get_volume(ctx->volume);
+ }
}
return as;
}
@@ -475,7 +493,7 @@ static void afs_kill_super(struct super_block *sb)
if (as->dyn_root)
afs_dynroot_depopulate(sb);
-
+
/* Clear the callback interests (which will do ilookup5) before
* deactivating the superblock.
*/
@@ -488,111 +506,103 @@ static void afs_kill_super(struct super_block *sb)
}
/*
- * get an AFS superblock
+ * Get an AFS superblock and root directory.
*/
-static struct dentry *afs_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *options)
+static int afs_get_tree(struct fs_context *fc)
{
- struct afs_mount_params params;
+ struct afs_fs_context *ctx = fc->fs_private;
struct super_block *sb;
- struct afs_volume *candidate;
- struct key *key;
struct afs_super_info *as;
int ret;
- _enter(",,%s,%p", dev_name, options);
-
- memset(&params, 0, sizeof(params));
-
- ret = -EINVAL;
- if (current->nsproxy->net_ns != &init_net)
+ ret = afs_validate_fc(fc);
+ if (ret)
goto error;
- params.net_ns = current->nsproxy->net_ns;
- params.net = afs_net(params.net_ns);
-
- /* parse the options and device name */
- if (options) {
- ret = afs_parse_options(&params, options, &dev_name);
- if (ret < 0)
- goto error;
- }
-
- if (!params.dyn_root) {
- ret = afs_parse_device_name(&params, dev_name);
- if (ret < 0)
- goto error;
- /* try and do the mount securely */
- key = afs_request_key(params.cell);
- if (IS_ERR(key)) {
- _leave(" = %ld [key]", PTR_ERR(key));
- ret = PTR_ERR(key);
- goto error;
- }
- params.key = key;
- }
+ _enter("");
/* allocate a superblock info record */
ret = -ENOMEM;
- as = afs_alloc_sbi(&params);
+ as = afs_alloc_sbi(fc);
if (!as)
- goto error_key;
-
- if (!params.dyn_root) {
- /* Assume we're going to need a volume record; at the very
- * least we can use it to update the volume record if we have
- * one already. This checks that the volume exists within the
- * cell.
- */
- candidate = afs_create_volume(&params);
- if (IS_ERR(candidate)) {
- ret = PTR_ERR(candidate);
- goto error_as;
- }
-
- as->volume = candidate;
- }
+ goto error;
+ fc->s_fs_info = as;
/* allocate a deviceless superblock */
- sb = sget(fs_type,
- as->dyn_root ? afs_dynroot_test_super : afs_test_super,
- afs_set_super, flags, as);
+ sb = sget_fc(fc,
+ as->dyn_root ? afs_dynroot_test_super : afs_test_super,
+ afs_set_super);
if (IS_ERR(sb)) {
ret = PTR_ERR(sb);
- goto error_as;
+ goto error;
}
if (!sb->s_root) {
/* initial superblock/root creation */
_debug("create");
- ret = afs_fill_super(sb, &params);
+ ret = afs_fill_super(sb, ctx);
if (ret < 0)
goto error_sb;
- as = NULL;
sb->s_flags |= SB_ACTIVE;
} else {
_debug("reuse");
ASSERTCMP(sb->s_flags, &, SB_ACTIVE);
- afs_destroy_sbi(as);
- as = NULL;
}
- afs_put_cell(params.net, params.cell);
- key_put(params.key);
+ fc->root = dget(sb->s_root);
_leave(" = 0 [%p]", sb);
- return dget(sb->s_root);
+ return 0;
error_sb:
deactivate_locked_super(sb);
- goto error_key;
-error_as:
- afs_destroy_sbi(as);
-error_key:
- key_put(params.key);
error:
- afs_put_cell(params.net, params.cell);
_leave(" = %d", ret);
- return ERR_PTR(ret);
+ return ret;
+}
+
+static void afs_free_fc(struct fs_context *fc)
+{
+ struct afs_fs_context *ctx = fc->fs_private;
+
+ afs_destroy_sbi(fc->s_fs_info);
+ afs_put_volume(ctx->cell, ctx->volume);
+ afs_put_cell(ctx->net, ctx->cell);
+ key_put(ctx->key);
+ kfree(ctx);
+}
+
+static const struct fs_context_operations afs_context_ops = {
+ .free = afs_free_fc,
+ .parse_param = afs_parse_param,
+ .get_tree = afs_get_tree,
+};
+
+/*
+ * Set up the filesystem mount context.
+ */
+static int afs_init_fs_context(struct fs_context *fc)
+{
+ struct afs_fs_context *ctx;
+ struct afs_cell *cell;
+
+ ctx = kzalloc(sizeof(struct afs_fs_context), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->type = AFSVL_ROVOL;
+ ctx->net = afs_net(fc->net_ns);
+
+ /* Default to the workstation cell. */
+ rcu_read_lock();
+ cell = afs_lookup_cell_rcu(ctx->net, NULL, 0);
+ rcu_read_unlock();
+ if (IS_ERR(cell))
+ cell = NULL;
+ ctx->cell = cell;
+
+ fc->fs_private = ctx;
+ fc->ops = &afs_context_ops;
+ return 0;
}
/*
diff --git a/fs/afs/volume.c b/fs/afs/volume.c
index 00975ed3640f..f6eba2def0a1 100644
--- a/fs/afs/volume.c
+++ b/fs/afs/volume.c
@@ -21,7 +21,7 @@ static const char *const afs_voltypes[] = { "R/W", "R/O", "BAK" };
/*
* Allocate a volume record and load it up from a vldb record.
*/
-static struct afs_volume *afs_alloc_volume(struct afs_mount_params *params,
+static struct afs_volume *afs_alloc_volume(struct afs_fs_context *params,
struct afs_vldb_entry *vldb,
unsigned long type_mask)
{
@@ -113,7 +113,7 @@ static struct afs_vldb_entry *afs_vl_lookup_vldb(struct afs_cell *cell,
* - Rule 3: If parent volume is R/W, then only mount R/W volume unless
* explicitly told otherwise
*/
-struct afs_volume *afs_create_volume(struct afs_mount_params *params)
+struct afs_volume *afs_create_volume(struct afs_fs_context *params)
{
struct afs_vldb_entry *vldb;
struct afs_volume *volume;
diff --git a/fs/filesystems.c b/fs/filesystems.c
index b03f57b1105b..9135646e41ac 100644
--- a/fs/filesystems.c
+++ b/fs/filesystems.c
@@ -16,6 +16,7 @@
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
+#include <linux/fs_parser.h>
/*
* Handling of filesystem drivers list.
@@ -73,6 +74,9 @@ int register_filesystem(struct file_system_type * fs)
int res = 0;
struct file_system_type ** p;
+ if (fs->parameters && !fs_validate_description(fs->parameters))
+ return -EINVAL;
+
BUG_ON(strchr(fs->name, '.'));
if (fs->next)
return -EBUSY;
diff --git a/fs/fs_context.c b/fs/fs_context.c
new file mode 100644
index 000000000000..87e3546b9a52
--- /dev/null
+++ b/fs/fs_context.c
@@ -0,0 +1,642 @@
+/* Provide a way to create a superblock configuration context within the kernel
+ * that allows a superblock to be set up prior to mounting.
+ *
+ * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/nsproxy.h>
+#include <linux/slab.h>
+#include <linux/magic.h>
+#include <linux/security.h>
+#include <linux/mnt_namespace.h>
+#include <linux/pid_namespace.h>
+#include <linux/user_namespace.h>
+#include <net/net_namespace.h>
+#include "mount.h"
+#include "internal.h"
+
+enum legacy_fs_param {
+ LEGACY_FS_UNSET_PARAMS,
+ LEGACY_FS_MONOLITHIC_PARAMS,
+ LEGACY_FS_INDIVIDUAL_PARAMS,
+};
+
+struct legacy_fs_context {
+ char *legacy_data; /* Data page for legacy filesystems */
+ size_t data_size;
+ enum legacy_fs_param param_type;
+};
+
+static int legacy_init_fs_context(struct fs_context *fc);
+
+static const struct constant_table common_set_sb_flag[] = {
+ { "dirsync", SB_DIRSYNC },
+ { "lazytime", SB_LAZYTIME },
+ { "mand", SB_MANDLOCK },
+ { "posixacl", SB_POSIXACL },
+ { "ro", SB_RDONLY },
+ { "sync", SB_SYNCHRONOUS },
+};
+
+static const struct constant_table common_clear_sb_flag[] = {
+ { "async", SB_SYNCHRONOUS },
+ { "nolazytime", SB_LAZYTIME },
+ { "nomand", SB_MANDLOCK },
+ { "rw", SB_RDONLY },
+ { "silent", SB_SILENT },
+};
+
+static const char *const forbidden_sb_flag[] = {
+ "bind",
+ "dev",
+ "exec",
+ "move",
+ "noatime",
+ "nodev",
+ "nodiratime",
+ "noexec",
+ "norelatime",
+ "nostrictatime",
+ "nosuid",
+ "private",
+ "rec",
+ "relatime",
+ "remount",
+ "shared",
+ "slave",
+ "strictatime",
+ "suid",
+ "unbindable",
+};
+
+/*
+ * Check for a common mount option that manipulates s_flags.
+ */
+static int vfs_parse_sb_flag(struct fs_context *fc, const char *key)
+{
+ unsigned int token;
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(forbidden_sb_flag); i++)
+ if (strcmp(key, forbidden_sb_flag[i]) == 0)
+ return -EINVAL;
+
+ token = lookup_constant(common_set_sb_flag, key, 0);
+ if (token) {
+ fc->sb_flags |= token;
+ fc->sb_flags_mask |= token;
+ return 0;
+ }
+
+ token = lookup_constant(common_clear_sb_flag, key, 0);
+ if (token) {
+ fc->sb_flags &= ~token;
+ fc->sb_flags_mask |= token;
+ return 0;
+ }
+
+ return -ENOPARAM;
+}
+
+/**
+ * vfs_parse_fs_param - Add a single parameter to a superblock config
+ * @fc: The filesystem context to modify
+ * @param: The parameter
+ *
+ * A single mount option in string form is applied to the filesystem context
+ * being set up. Certain standard options (for example "ro") are translated
+ * into flag bits without going to the filesystem. The active security module
+ * is allowed to observe and poach options. Any other options are passed over
+ * to the filesystem to parse.
+ *
+ * This may be called multiple times for a context.
+ *
+ * Returns 0 on success and a negative error code on failure. In the event of
+ * failure, supplementary error information may have been set.
+ */
+int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param)
+{
+ int ret;
+
+ if (!param->key)
+ return invalf(fc, "Unnamed parameter\n");
+
+ ret = vfs_parse_sb_flag(fc, param->key);
+ if (ret != -ENOPARAM)
+ return ret;
+
+ ret = security_fs_context_parse_param(fc, param);
+ if (ret != -ENOPARAM)
+ /* Param belongs to the LSM or is disallowed by the LSM; so
+ * don't pass to the FS.
+ */
+ return ret;
+
+ if (fc->ops->parse_param) {
+ ret = fc->ops->parse_param(fc, param);
+ if (ret != -ENOPARAM)
+ return ret;
+ }
+
+ /* If the filesystem doesn't take any arguments, give it the
+ * default handling of source.
+ */
+ if (strcmp(param->key, "source") == 0) {
+ if (param->type != fs_value_is_string)
+ return invalf(fc, "VFS: Non-string source");
+ if (fc->source)
+ return invalf(fc, "VFS: Multiple sources");
+ fc->source = param->string;
+ param->string = NULL;
+ return 0;
+ }
+
+ return invalf(fc, "%s: Unknown parameter '%s'",
+ fc->fs_type->name, param->key);
+}
+EXPORT_SYMBOL(vfs_parse_fs_param);
+
+/**
+ * vfs_parse_fs_string - Convenience function to just parse a string.
+ */
+int vfs_parse_fs_string(struct fs_context *fc, const char *key,
+ const char *value, size_t v_size)
+{
+ int ret;
+
+ struct fs_parameter param = {
+ .key = key,
+ .type = fs_value_is_string,
+ .size = v_size,
+ };
+
+ if (v_size > 0) {
+ param.string = kmemdup_nul(value, v_size, GFP_KERNEL);
+ if (!param.string)
+ return -ENOMEM;
+ }
+
+ ret = vfs_parse_fs_param(fc, &param);
+ kfree(param.string);
+ return ret;
+}
+EXPORT_SYMBOL(vfs_parse_fs_string);
+
+/**
+ * generic_parse_monolithic - Parse key[=val][,key[=val]]* mount data
+ * @ctx: The superblock configuration to fill in.
+ * @data: The data to parse
+ *
+ * Parse a blob of data that's in key[=val][,key[=val]]* form. This can be
+ * called from the ->monolithic_mount_data() fs_context operation.
+ *
+ * Returns 0 on success or the error returned by the ->parse_option() fs_context
+ * operation on failure.
+ */
+int generic_parse_monolithic(struct fs_context *fc, void *data)
+{
+ char *options = data, *key;
+ int ret = 0;
+
+ if (!options)
+ return 0;
+
+ ret = security_sb_eat_lsm_opts(options, &fc->security);
+ if (ret)
+ return ret;
+
+ while ((key = strsep(&options, ",")) != NULL) {
+ if (*key) {
+ size_t v_len = 0;
+ char *value = strchr(key, '=');
+
+ if (value) {
+ if (value == key)
+ continue;
+ *value++ = 0;
+ v_len = strlen(value);
+ }
+ ret = vfs_parse_fs_string(fc, key, value, v_len);
+ if (ret < 0)
+ break;
+ }
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(generic_parse_monolithic);
+
+/**
+ * alloc_fs_context - Create a filesystem context.
+ * @fs_type: The filesystem type.
+ * @reference: The dentry from which this one derives (or NULL)
+ * @sb_flags: Filesystem/superblock flags (SB_*)
+ * @sb_flags_mask: Applicable members of @sb_flags
+ * @purpose: The purpose that this configuration shall be used for.
+ *
+ * Open a filesystem and create a mount context. The mount context is
+ * initialised with the supplied flags and, if a submount/automount from
+ * another superblock (referred to by @reference) is supplied, may have
+ * parameters such as namespaces copied across from that superblock.
+ */
+static struct fs_context *alloc_fs_context(struct file_system_type *fs_type,
+ struct dentry *reference,
+ unsigned int sb_flags,
+ unsigned int sb_flags_mask,
+ enum fs_context_purpose purpose)
+{
+ int (*init_fs_context)(struct fs_context *);
+ struct fs_context *fc;
+ int ret = -ENOMEM;
+
+ fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
+ if (!fc)
+ return ERR_PTR(-ENOMEM);
+
+ fc->purpose = purpose;
+ fc->sb_flags = sb_flags;
+ fc->sb_flags_mask = sb_flags_mask;
+ fc->fs_type = get_filesystem(fs_type);
+ fc->cred = get_current_cred();
+ fc->net_ns = get_net(current->nsproxy->net_ns);
+
+ switch (purpose) {
+ case FS_CONTEXT_FOR_MOUNT:
+ fc->user_ns = get_user_ns(fc->cred->user_ns);
+ break;
+ case FS_CONTEXT_FOR_SUBMOUNT:
+ fc->user_ns = get_user_ns(reference->d_sb->s_user_ns);
+ break;
+ case FS_CONTEXT_FOR_RECONFIGURE:
+ /* We don't pin any namespaces as the superblock's
+ * subscriptions cannot be changed at this point.
+ */
+ atomic_inc(&reference->d_sb->s_active);
+ fc->root = dget(reference);
+ break;
+ }
+
+ /* TODO: Make all filesystems support this unconditionally */
+ init_fs_context = fc->fs_type->init_fs_context;
+ if (!init_fs_context)
+ init_fs_context = legacy_init_fs_context;
+
+ ret = init_fs_context(fc);
+ if (ret < 0)
+ goto err_fc;
+ fc->need_free = true;
+ return fc;
+
+err_fc:
+ put_fs_context(fc);
+ return ERR_PTR(ret);
+}
+
+struct fs_context *fs_context_for_mount(struct file_system_type *fs_type,
+ unsigned int sb_flags)
+{
+ return alloc_fs_context(fs_type, NULL, sb_flags, 0,
+ FS_CONTEXT_FOR_MOUNT);
+}
+EXPORT_SYMBOL(fs_context_for_mount);
+
+struct fs_context *fs_context_for_reconfigure(struct dentry *dentry,
+ unsigned int sb_flags,
+ unsigned int sb_flags_mask)
+{
+ return alloc_fs_context(dentry->d_sb->s_type, dentry, sb_flags,
+ sb_flags_mask, FS_CONTEXT_FOR_RECONFIGURE);
+}
+EXPORT_SYMBOL(fs_context_for_reconfigure);
+
+struct fs_context *fs_context_for_submount(struct file_system_type *type,
+ struct dentry *reference)
+{
+ return alloc_fs_context(type, reference, 0, 0, FS_CONTEXT_FOR_SUBMOUNT);
+}
+EXPORT_SYMBOL(fs_context_for_submount);
+
+void fc_drop_locked(struct fs_context *fc)
+{
+ struct super_block *sb = fc->root->d_sb;
+ dput(fc->root);
+ fc->root = NULL;
+ deactivate_locked_super(sb);
+}
+
+static void legacy_fs_context_free(struct fs_context *fc);
+
+/**
+ * vfs_dup_fc_config: Duplicate a filesystem context.
+ * @src_fc: The context to copy.
+ */
+struct fs_context *vfs_dup_fs_context(struct fs_context *src_fc)
+{
+ struct fs_context *fc;
+ int ret;
+
+ if (!src_fc->ops->dup)
+ return ERR_PTR(-EOPNOTSUPP);
+
+ fc = kmemdup(src_fc, sizeof(struct fs_context), GFP_KERNEL);
+ if (!fc)
+ return ERR_PTR(-ENOMEM);
+
+ fc->fs_private = NULL;
+ fc->s_fs_info = NULL;
+ fc->source = NULL;
+ fc->security = NULL;
+ get_filesystem(fc->fs_type);
+ get_net(fc->net_ns);
+ get_user_ns(fc->user_ns);
+ get_cred(fc->cred);
+
+ /* Can't call put until we've called ->dup */
+ ret = fc->ops->dup(fc, src_fc);
+ if (ret < 0)
+ goto err_fc;
+
+ ret = security_fs_context_dup(fc, src_fc);
+ if (ret < 0)
+ goto err_fc;
+ return fc;
+
+err_fc:
+ put_fs_context(fc);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(vfs_dup_fs_context);
+
+#ifdef CONFIG_PRINTK
+/**
+ * logfc - Log a message to a filesystem context
+ * @fc: The filesystem context to log to.
+ * @fmt: The format of the buffer.
+ */
+void logfc(struct fs_context *fc, const char *fmt, ...)
+{
+ va_list va;
+
+ va_start(va, fmt);
+
+ switch (fmt[0]) {
+ case 'w':
+ vprintk_emit(0, LOGLEVEL_WARNING, NULL, 0, fmt, va);
+ break;
+ case 'e':
+ vprintk_emit(0, LOGLEVEL_ERR, NULL, 0, fmt, va);
+ break;
+ default:
+ vprintk_emit(0, LOGLEVEL_NOTICE, NULL, 0, fmt, va);
+ break;
+ }
+
+ pr_cont("\n");
+ va_end(va);
+}
+EXPORT_SYMBOL(logfc);
+#endif
+
+/**
+ * put_fs_context - Dispose of a superblock configuration context.
+ * @fc: The context to dispose of.
+ */
+void put_fs_context(struct fs_context *fc)
+{
+ struct super_block *sb;
+
+ if (fc->root) {
+ sb = fc->root->d_sb;
+ dput(fc->root);
+ fc->root = NULL;
+ deactivate_super(sb);
+ }
+
+ if (fc->need_free && fc->ops && fc->ops->free)
+ fc->ops->free(fc);
+
+ security_free_mnt_opts(&fc->security);
+ put_net(fc->net_ns);
+ put_user_ns(fc->user_ns);
+ put_cred(fc->cred);
+ kfree(fc->subtype);
+ put_filesystem(fc->fs_type);
+ kfree(fc->source);
+ kfree(fc);
+}
+EXPORT_SYMBOL(put_fs_context);
+
+/*
+ * Free the config for a filesystem that doesn't support fs_context.
+ */
+static void legacy_fs_context_free(struct fs_context *fc)
+{
+ struct legacy_fs_context *ctx = fc->fs_private;
+
+ if (ctx) {
+ if (ctx->param_type == LEGACY_FS_INDIVIDUAL_PARAMS)
+ kfree(ctx->legacy_data);
+ kfree(ctx);
+ }
+}
+
+/*
+ * Duplicate a legacy config.
+ */
+static int legacy_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
+{
+ struct legacy_fs_context *ctx;
+ struct legacy_fs_context *src_ctx = src_fc->fs_private;
+
+ ctx = kmemdup(src_ctx, sizeof(*src_ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ if (ctx->param_type == LEGACY_FS_INDIVIDUAL_PARAMS) {
+ ctx->legacy_data = kmemdup(src_ctx->legacy_data,
+ src_ctx->data_size, GFP_KERNEL);
+ if (!ctx->legacy_data) {
+ kfree(ctx);
+ return -ENOMEM;
+ }
+ }
+
+ fc->fs_private = ctx;
+ return 0;
+}
+
+/*
+ * Add a parameter to a legacy config. We build up a comma-separated list of
+ * options.
+ */
+static int legacy_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+ struct legacy_fs_context *ctx = fc->fs_private;
+ unsigned int size = ctx->data_size;
+ size_t len = 0;
+
+ if (strcmp(param->key, "source") == 0) {
+ if (param->type != fs_value_is_string)
+ return invalf(fc, "VFS: Legacy: Non-string source");
+ if (fc->source)
+ return invalf(fc, "VFS: Legacy: Multiple sources");
+ fc->source = param->string;
+ param->string = NULL;
+ return 0;
+ }
+
+ if ((fc->fs_type->fs_flags & FS_HAS_SUBTYPE) &&
+ strcmp(param->key, "subtype") == 0) {
+ if (param->type != fs_value_is_string)
+ return invalf(fc, "VFS: Legacy: Non-string subtype");
+ if (fc->subtype)
+ return invalf(fc, "VFS: Legacy: Multiple subtype");
+ fc->subtype = param->string;
+ param->string = NULL;
+ return 0;
+ }
+
+ if (ctx->param_type == LEGACY_FS_MONOLITHIC_PARAMS)
+ return invalf(fc, "VFS: Legacy: Can't mix monolithic and individual options");
+
+ switch (param->type) {
+ case fs_value_is_string:
+ len = 1 + param->size;
+ /* Fall through */
+ case fs_value_is_flag:
+ len += strlen(param->key);
+ break;
+ default:
+ return invalf(fc, "VFS: Legacy: Parameter type for '%s' not supported",
+ param->key);
+ }
+
+ if (len > PAGE_SIZE - 2 - size)
+ return invalf(fc, "VFS: Legacy: Cumulative options too large");
+ if (strchr(param->key, ',') ||
+ (param->type == fs_value_is_string &&
+ memchr(param->string, ',', param->size)))
+ return invalf(fc, "VFS: Legacy: Option '%s' contained comma",
+ param->key);
+ if (!ctx->legacy_data) {
+ ctx->legacy_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!ctx->legacy_data)
+ return -ENOMEM;
+ }
+
+ ctx->legacy_data[size++] = ',';
+ len = strlen(param->key);
+ memcpy(ctx->legacy_data + size, param->key, len);
+ size += len;
+ if (param->type == fs_value_is_string) {
+ ctx->legacy_data[size++] = '=';
+ memcpy(ctx->legacy_data + size, param->string, param->size);
+ size += param->size;
+ }
+ ctx->legacy_data[size] = '\0';
+ ctx->data_size = size;
+ ctx->param_type = LEGACY_FS_INDIVIDUAL_PARAMS;
+ return 0;
+}
+
+/*
+ * Add monolithic mount data.
+ */
+static int legacy_parse_monolithic(struct fs_context *fc, void *data)
+{
+ struct legacy_fs_context *ctx = fc->fs_private;
+
+ if (ctx->param_type != LEGACY_FS_UNSET_PARAMS) {
+ pr_warn("VFS: Can't mix monolithic and individual options\n");
+ return -EINVAL;
+ }
+
+ ctx->legacy_data = data;
+ ctx->param_type = LEGACY_FS_MONOLITHIC_PARAMS;
+ if (!ctx->legacy_data)
+ return 0;
+
+ if (fc->fs_type->fs_flags & FS_BINARY_MOUNTDATA)
+ return 0;
+ return security_sb_eat_lsm_opts(ctx->legacy_data, &fc->security);
+}
+
+/*
+ * Get a mountable root with the legacy mount command.
+ */
+static int legacy_get_tree(struct fs_context *fc)
+{
+ struct legacy_fs_context *ctx = fc->fs_private;
+ struct super_block *sb;
+ struct dentry *root;
+
+ root = fc->fs_type->mount(fc->fs_type, fc->sb_flags,
+ fc->source, ctx->legacy_data);
+ if (IS_ERR(root))
+ return PTR_ERR(root);
+
+ sb = root->d_sb;
+ BUG_ON(!sb);
+
+ fc->root = root;
+ return 0;
+}
+
+/*
+ * Handle remount.
+ */
+static int legacy_reconfigure(struct fs_context *fc)
+{
+ struct legacy_fs_context *ctx = fc->fs_private;
+ struct super_block *sb = fc->root->d_sb;
+
+ if (!sb->s_op->remount_fs)
+ return 0;
+
+ return sb->s_op->remount_fs(sb, &fc->sb_flags,
+ ctx ? ctx->legacy_data : NULL);
+}
+
+const struct fs_context_operations legacy_fs_context_ops = {
+ .free = legacy_fs_context_free,
+ .dup = legacy_fs_context_dup,
+ .parse_param = legacy_parse_param,
+ .parse_monolithic = legacy_parse_monolithic,
+ .get_tree = legacy_get_tree,
+ .reconfigure = legacy_reconfigure,
+};
+
+/*
+ * Initialise a legacy context for a filesystem that doesn't support
+ * fs_context.
+ */
+static int legacy_init_fs_context(struct fs_context *fc)
+{
+ fc->fs_private = kzalloc(sizeof(struct legacy_fs_context), GFP_KERNEL);
+ if (!fc->fs_private)
+ return -ENOMEM;
+ fc->ops = &legacy_fs_context_ops;
+ return 0;
+}
+
+int parse_monolithic_mount_data(struct fs_context *fc, void *data)
+{
+ int (*monolithic_mount_data)(struct fs_context *, void *);
+
+ monolithic_mount_data = fc->ops->parse_monolithic;
+ if (!monolithic_mount_data)
+ monolithic_mount_data = generic_parse_monolithic;
+
+ return monolithic_mount_data(fc, data);
+}
diff --git a/fs/fs_parser.c b/fs/fs_parser.c
new file mode 100644
index 000000000000..842e8f749db6
--- /dev/null
+++ b/fs/fs_parser.c
@@ -0,0 +1,447 @@
+/* Filesystem parameter parser.
+ *
+ * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/export.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <linux/namei.h>
+#include "internal.h"
+
+static const struct constant_table bool_names[] = {
+ { "0", false },
+ { "1", true },
+ { "false", false },
+ { "no", false },
+ { "true", true },
+ { "yes", true },
+};
+
+/**
+ * lookup_constant - Look up a constant by name in an ordered table
+ * @tbl: The table of constants to search.
+ * @tbl_size: The size of the table.
+ * @name: The name to look up.
+ * @not_found: The value to return if the name is not found.
+ */
+int __lookup_constant(const struct constant_table *tbl, size_t tbl_size,
+ const char *name, int not_found)
+{
+ unsigned int i;
+
+ for (i = 0; i < tbl_size; i++)
+ if (strcmp(name, tbl[i].name) == 0)
+ return tbl[i].value;
+
+ return not_found;
+}
+EXPORT_SYMBOL(__lookup_constant);
+
+static const struct fs_parameter_spec *fs_lookup_key(
+ const struct fs_parameter_description *desc,
+ const char *name)
+{
+ const struct fs_parameter_spec *p;
+
+ if (!desc->specs)
+ return NULL;
+
+ for (p = desc->specs; p->name; p++)
+ if (strcmp(p->name, name) == 0)
+ return p;
+
+ return NULL;
+}
+
+/*
+ * fs_parse - Parse a filesystem configuration parameter
+ * @fc: The filesystem context to log errors through.
+ * @desc: The parameter description to use.
+ * @param: The parameter.
+ * @result: Where to place the result of the parse
+ *
+ * Parse a filesystem configuration parameter and attempt a conversion for a
+ * simple parameter for which this is requested. If successful, the determined
+ * parameter ID is placed into @result->key, the desired type is indicated in
+ * @result->t and any converted value is placed into an appropriate member of
+ * the union in @result.
+ *
+ * The function returns the parameter number if the parameter was matched,
+ * -ENOPARAM if it wasn't matched and @desc->ignore_unknown indicated that
+ * unknown parameters are okay and -EINVAL if there was a conversion issue or
+ * the parameter wasn't recognised and unknowns aren't okay.
+ */
+int fs_parse(struct fs_context *fc,
+ const struct fs_parameter_description *desc,
+ struct fs_parameter *param,
+ struct fs_parse_result *result)
+{
+ const struct fs_parameter_spec *p;
+ const struct fs_parameter_enum *e;
+ int ret = -ENOPARAM, b;
+
+ result->has_value = !!param->string;
+ result->negated = false;
+ result->uint_64 = 0;
+
+ p = fs_lookup_key(desc, param->key);
+ if (!p) {
+ /* If we didn't find something that looks like "noxxx", see if
+ * "xxx" takes the "no"-form negative - but only if there
+ * wasn't an value.
+ */
+ if (result->has_value)
+ goto unknown_parameter;
+ if (param->key[0] != 'n' || param->key[1] != 'o' || !param->key[2])
+ goto unknown_parameter;
+
+ p = fs_lookup_key(desc, param->key + 2);
+ if (!p)
+ goto unknown_parameter;
+ if (!(p->flags & fs_param_neg_with_no))
+ goto unknown_parameter;
+ result->boolean = false;
+ result->negated = true;
+ }
+
+ if (p->flags & fs_param_deprecated)
+ warnf(fc, "%s: Deprecated parameter '%s'",
+ desc->name, param->key);
+
+ if (result->negated)
+ goto okay;
+
+ /* Certain parameter types only take a string and convert it. */
+ switch (p->type) {
+ case __fs_param_wasnt_defined:
+ return -EINVAL;
+ case fs_param_is_u32:
+ case fs_param_is_u32_octal:
+ case fs_param_is_u32_hex:
+ case fs_param_is_s32:
+ case fs_param_is_u64:
+ case fs_param_is_enum:
+ case fs_param_is_string:
+ if (param->type != fs_value_is_string)
+ goto bad_value;
+ if (!result->has_value) {
+ if (p->flags & fs_param_v_optional)
+ goto okay;
+ goto bad_value;
+ }
+ /* Fall through */
+ default:
+ break;
+ }
+
+ /* Try to turn the type we were given into the type desired by the
+ * parameter and give an error if we can't.
+ */
+ switch (p->type) {
+ case fs_param_is_flag:
+ if (param->type != fs_value_is_flag &&
+ (param->type != fs_value_is_string || result->has_value))
+ return invalf(fc, "%s: Unexpected value for '%s'",
+ desc->name, param->key);
+ result->boolean = true;
+ goto okay;
+
+ case fs_param_is_bool:
+ switch (param->type) {
+ case fs_value_is_flag:
+ result->boolean = true;
+ goto okay;
+ case fs_value_is_string:
+ if (param->size == 0) {
+ result->boolean = true;
+ goto okay;
+ }
+ b = lookup_constant(bool_names, param->string, -1);
+ if (b == -1)
+ goto bad_value;
+ result->boolean = b;
+ goto okay;
+ default:
+ goto bad_value;
+ }
+
+ case fs_param_is_u32:
+ ret = kstrtouint(param->string, 0, &result->uint_32);
+ goto maybe_okay;
+ case fs_param_is_u32_octal:
+ ret = kstrtouint(param->string, 8, &result->uint_32);
+ goto maybe_okay;
+ case fs_param_is_u32_hex:
+ ret = kstrtouint(param->string, 16, &result->uint_32);
+ goto maybe_okay;
+ case fs_param_is_s32:
+ ret = kstrtoint(param->string, 0, &result->int_32);
+ goto maybe_okay;
+ case fs_param_is_u64:
+ ret = kstrtoull(param->string, 0, &result->uint_64);
+ goto maybe_okay;
+
+ case fs_param_is_enum:
+ for (e = desc->enums; e->name[0]; e++) {
+ if (e->opt == p->opt &&
+ strcmp(e->name, param->string) == 0) {
+ result->uint_32 = e->value;
+ goto okay;
+ }
+ }
+ goto bad_value;
+
+ case fs_param_is_string:
+ goto okay;
+ case fs_param_is_blob:
+ if (param->type != fs_value_is_blob)
+ goto bad_value;
+ goto okay;
+
+ case fs_param_is_fd: {
+ if (param->type != fs_value_is_file)
+ goto bad_value;
+ goto okay;
+ }
+
+ case fs_param_is_blockdev:
+ case fs_param_is_path:
+ goto okay;
+ default:
+ BUG();
+ }
+
+maybe_okay:
+ if (ret < 0)
+ goto bad_value;
+okay:
+ return p->opt;
+
+bad_value:
+ return invalf(fc, "%s: Bad value for '%s'", desc->name, param->key);
+unknown_parameter:
+ return -ENOPARAM;
+}
+EXPORT_SYMBOL(fs_parse);
+
+/**
+ * fs_lookup_param - Look up a path referred to by a parameter
+ * @fc: The filesystem context to log errors through.
+ * @param: The parameter.
+ * @want_bdev: T if want a blockdev
+ * @_path: The result of the lookup
+ */
+int fs_lookup_param(struct fs_context *fc,
+ struct fs_parameter *param,
+ bool want_bdev,
+ struct path *_path)
+{
+ struct filename *f;
+ unsigned int flags = 0;
+ bool put_f;
+ int ret;
+
+ switch (param->type) {
+ case fs_value_is_string:
+ f = getname_kernel(param->string);
+ if (IS_ERR(f))
+ return PTR_ERR(f);
+ put_f = true;
+ break;
+ case fs_value_is_filename_empty:
+ flags = LOOKUP_EMPTY;
+ /* Fall through */
+ case fs_value_is_filename:
+ f = param->name;
+ put_f = false;
+ break;
+ default:
+ return invalf(fc, "%s: not usable as path", param->key);
+ }
+
+ ret = filename_lookup(param->dirfd, f, flags, _path, NULL);
+ if (ret < 0) {
+ errorf(fc, "%s: Lookup failure for '%s'", param->key, f->name);
+ goto out;
+ }
+
+ if (want_bdev &&
+ !S_ISBLK(d_backing_inode(_path->dentry)->i_mode)) {
+ path_put(_path);
+ _path->dentry = NULL;
+ _path->mnt = NULL;
+ errorf(fc, "%s: Non-blockdev passed as '%s'",
+ param->key, f->name);
+ ret = -ENOTBLK;
+ }
+
+out:
+ if (put_f)
+ putname(f);
+ return ret;
+}
+EXPORT_SYMBOL(fs_lookup_param);
+
+#ifdef CONFIG_VALIDATE_FS_PARSER
+/**
+ * validate_constant_table - Validate a constant table
+ * @name: Name to use in reporting
+ * @tbl: The constant table to validate.
+ * @tbl_size: The size of the table.
+ * @low: The lowest permissible value.
+ * @high: The highest permissible value.
+ * @special: One special permissible value outside of the range.
+ */
+bool validate_constant_table(const struct constant_table *tbl, size_t tbl_size,
+ int low, int high, int special)
+{
+ size_t i;
+ bool good = true;
+
+ if (tbl_size == 0) {
+ pr_warn("VALIDATE C-TBL: Empty\n");
+ return true;
+ }
+
+ for (i = 0; i < tbl_size; i++) {
+ if (!tbl[i].name) {
+ pr_err("VALIDATE C-TBL[%zu]: Null\n", i);
+ good = false;
+ } else if (i > 0 && tbl[i - 1].name) {
+ int c = strcmp(tbl[i-1].name, tbl[i].name);
+
+ if (c == 0) {
+ pr_err("VALIDATE C-TBL[%zu]: Duplicate %s\n",
+ i, tbl[i].name);
+ good = false;
+ }
+ if (c > 0) {
+ pr_err("VALIDATE C-TBL[%zu]: Missorted %s>=%s\n",
+ i, tbl[i-1].name, tbl[i].name);
+ good = false;
+ }
+ }
+
+ if (tbl[i].value != special &&
+ (tbl[i].value < low || tbl[i].value > high)) {
+ pr_err("VALIDATE C-TBL[%zu]: %s->%d const out of range (%d-%d)\n",
+ i, tbl[i].name, tbl[i].value, low, high);
+ good = false;
+ }
+ }
+
+ return good;
+}
+
+/**
+ * fs_validate_description - Validate a parameter description
+ * @desc: The parameter description to validate.
+ */
+bool fs_validate_description(const struct fs_parameter_description *desc)
+{
+ const struct fs_parameter_spec *param, *p2;
+ const struct fs_parameter_enum *e;
+ const char *name = desc->name;
+ unsigned int nr_params = 0;
+ bool good = true, enums = false;
+
+ pr_notice("*** VALIDATE %s ***\n", name);
+
+ if (!name[0]) {
+ pr_err("VALIDATE Parser: No name\n");
+ name = "Unknown";
+ good = false;
+ }
+
+ if (desc->specs) {
+ for (param = desc->specs; param->name; param++) {
+ enum fs_parameter_type t = param->type;
+
+ /* Check that the type is in range */
+ if (t == __fs_param_wasnt_defined ||
+ t >= nr__fs_parameter_type) {
+ pr_err("VALIDATE %s: PARAM[%s] Bad type %u\n",
+ name, param->name, t);
+ good = false;
+ } else if (t == fs_param_is_enum) {
+ enums = true;
+ }
+
+ /* Check for duplicate parameter names */
+ for (p2 = desc->specs; p2 < param; p2++) {
+ if (strcmp(param->name, p2->name) == 0) {
+ pr_err("VALIDATE %s: PARAM[%s]: Duplicate\n",
+ name, param->name);
+ good = false;
+ }
+ }
+ }
+
+ nr_params = param - desc->specs;
+ }
+
+ if (desc->enums) {
+ if (!nr_params) {
+ pr_err("VALIDATE %s: Enum table but no parameters\n",
+ name);
+ good = false;
+ goto no_enums;
+ }
+ if (!enums) {
+ pr_err("VALIDATE %s: Enum table but no enum-type values\n",
+ name);
+ good = false;
+ goto no_enums;
+ }
+
+ for (e = desc->enums; e->name[0]; e++) {
+ /* Check that all entries in the enum table have at
+ * least one parameter that uses them.
+ */
+ for (param = desc->specs; param->name; param++) {
+ if (param->opt == e->opt &&
+ param->type != fs_param_is_enum) {
+ pr_err("VALIDATE %s: e[%lu] enum val for %s\n",
+ name, e - desc->enums, param->name);
+ good = false;
+ }
+ }
+ }
+
+ /* Check that all enum-type parameters have at least one enum
+ * value in the enum table.
+ */
+ for (param = desc->specs; param->name; param++) {
+ if (param->type != fs_param_is_enum)
+ continue;
+ for (e = desc->enums; e->name[0]; e++)
+ if (e->opt == param->opt)
+ break;
+ if (!e->name[0]) {
+ pr_err("VALIDATE %s: PARAM[%s] enum with no values\n",
+ name, param->name);
+ good = false;
+ }
+ }
+ } else {
+ if (enums) {
+ pr_err("VALIDATE %s: enum-type values, but no enum table\n",
+ name);
+ good = false;
+ goto no_enums;
+ }
+ }
+
+no_enums:
+ return good;
+}
+#endif /* CONFIG_VALIDATE_FS_PARSER */
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index b0eef008de67..ec32fece5e1e 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -27,7 +27,7 @@
#include <linux/backing-dev.h>
#include <linux/hugetlb.h>
#include <linux/pagevec.h>
-#include <linux/parser.h>
+#include <linux/fs_parser.h>
#include <linux/mman.h>
#include <linux/slab.h>
#include <linux/dnotify.h>
@@ -45,11 +45,17 @@ const struct file_operations hugetlbfs_file_operations;
static const struct inode_operations hugetlbfs_dir_inode_operations;
static const struct inode_operations hugetlbfs_inode_operations;
-struct hugetlbfs_config {
+enum hugetlbfs_size_type { NO_SIZE, SIZE_STD, SIZE_PERCENT };
+
+struct hugetlbfs_fs_context {
struct hstate *hstate;
+ unsigned long long max_size_opt;
+ unsigned long long min_size_opt;
long max_hpages;
long nr_inodes;
long min_hpages;
+ enum hugetlbfs_size_type max_val_type;
+ enum hugetlbfs_size_type min_val_type;
kuid_t uid;
kgid_t gid;
umode_t mode;
@@ -57,22 +63,30 @@ struct hugetlbfs_config {
int sysctl_hugetlb_shm_group;
-enum {
- Opt_size, Opt_nr_inodes,
- Opt_mode, Opt_uid, Opt_gid,
- Opt_pagesize, Opt_min_size,
- Opt_err,
+enum hugetlb_param {
+ Opt_gid,
+ Opt_min_size,
+ Opt_mode,
+ Opt_nr_inodes,
+ Opt_pagesize,
+ Opt_size,
+ Opt_uid,
};
-static const match_table_t tokens = {
- {Opt_size, "size=%s"},
- {Opt_nr_inodes, "nr_inodes=%s"},
- {Opt_mode, "mode=%o"},
- {Opt_uid, "uid=%u"},
- {Opt_gid, "gid=%u"},
- {Opt_pagesize, "pagesize=%s"},
- {Opt_min_size, "min_size=%s"},
- {Opt_err, NULL},
+static const struct fs_parameter_spec hugetlb_param_specs[] = {
+ fsparam_u32 ("gid", Opt_gid),
+ fsparam_string("min_size", Opt_min_size),
+ fsparam_u32 ("mode", Opt_mode),
+ fsparam_string("nr_inodes", Opt_nr_inodes),
+ fsparam_string("pagesize", Opt_pagesize),
+ fsparam_string("size", Opt_size),
+ fsparam_u32 ("uid", Opt_uid),
+ {}
+};
+
+static const struct fs_parameter_description hugetlb_fs_parameters = {
+ .name = "hugetlbfs",
+ .specs = hugetlb_param_specs,
};
#ifdef CONFIG_NUMA
@@ -708,16 +722,16 @@ static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
}
static struct inode *hugetlbfs_get_root(struct super_block *sb,
- struct hugetlbfs_config *config)
+ struct hugetlbfs_fs_context *ctx)
{
struct inode *inode;
inode = new_inode(sb);
if (inode) {
inode->i_ino = get_next_ino();
- inode->i_mode = S_IFDIR | config->mode;
- inode->i_uid = config->uid;
- inode->i_gid = config->gid;
+ inode->i_mode = S_IFDIR | ctx->mode;
+ inode->i_uid = ctx->uid;
+ inode->i_gid = ctx->gid;
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
inode->i_op = &hugetlbfs_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
@@ -1093,8 +1107,6 @@ static const struct super_operations hugetlbfs_ops = {
.show_options = hugetlbfs_show_options,
};
-enum hugetlbfs_size_type { NO_SIZE, SIZE_STD, SIZE_PERCENT };
-
/*
* Convert size option passed from command line to number of huge pages
* in the pool specified by hstate. Size option could be in bytes
@@ -1117,170 +1129,151 @@ hugetlbfs_size_to_hpages(struct hstate *h, unsigned long long size_opt,
return size_opt;
}
-static int
-hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
+/*
+ * Parse one mount parameter.
+ */
+static int hugetlbfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
- char *p, *rest;
- substring_t args[MAX_OPT_ARGS];
- int option;
- unsigned long long max_size_opt = 0, min_size_opt = 0;
- enum hugetlbfs_size_type max_val_type = NO_SIZE, min_val_type = NO_SIZE;
-
- if (!options)
+ struct hugetlbfs_fs_context *ctx = fc->fs_private;
+ struct fs_parse_result result;
+ char *rest;
+ unsigned long ps;
+ int opt;
+
+ opt = fs_parse(fc, &hugetlb_fs_parameters, param, &result);
+ if (opt < 0)
+ return opt;
+
+ switch (opt) {
+ case Opt_uid:
+ ctx->uid = make_kuid(current_user_ns(), result.uint_32);
+ if (!uid_valid(ctx->uid))
+ goto bad_val;
return 0;
- while ((p = strsep(&options, ",")) != NULL) {
- int token;
- if (!*p)
- continue;
+ case Opt_gid:
+ ctx->gid = make_kgid(current_user_ns(), result.uint_32);
+ if (!gid_valid(ctx->gid))
+ goto bad_val;
+ return 0;
- token = match_token(p, tokens, args);
- switch (token) {
- case Opt_uid:
- if (match_int(&args[0], &option))
- goto bad_val;
- pconfig->uid = make_kuid(current_user_ns(), option);
- if (!uid_valid(pconfig->uid))
- goto bad_val;
- break;
+ case Opt_mode:
+ ctx->mode = result.uint_32 & 01777U;
+ return 0;
- case Opt_gid:
- if (match_int(&args[0], &option))
- goto bad_val;
- pconfig->gid = make_kgid(current_user_ns(), option);
- if (!gid_valid(pconfig->gid))
- goto bad_val;
- break;
+ case Opt_size:
+ /* memparse() will accept a K/M/G without a digit */
+ if (!isdigit(param->string[0]))
+ goto bad_val;
+ ctx->max_size_opt = memparse(param->string, &rest);
+ ctx->max_val_type = SIZE_STD;
+ if (*rest == '%')
+ ctx->max_val_type = SIZE_PERCENT;
+ return 0;
- case Opt_mode:
- if (match_octal(&args[0], &option))
- goto bad_val;
- pconfig->mode = option & 01777U;
- break;
+ case Opt_nr_inodes:
+ /* memparse() will accept a K/M/G without a digit */
+ if (!isdigit(param->string[0]))
+ goto bad_val;
+ ctx->nr_inodes = memparse(param->string, &rest);
+ return 0;
- case Opt_size: {
- /* memparse() will accept a K/M/G without a digit */
- if (!isdigit(*args[0].from))
- goto bad_val;
- max_size_opt = memparse(args[0].from, &rest);
- max_val_type = SIZE_STD;
- if (*rest == '%')
- max_val_type = SIZE_PERCENT;
- break;
+ case Opt_pagesize:
+ ps = memparse(param->string, &rest);
+ ctx->hstate = size_to_hstate(ps);
+ if (!ctx->hstate) {
+ pr_err("Unsupported page size %lu MB\n", ps >> 20);
+ return -EINVAL;
}
+ return 0;
- case Opt_nr_inodes:
- /* memparse() will accept a K/M/G without a digit */
- if (!isdigit(*args[0].from))
- goto bad_val;
- pconfig->nr_inodes = memparse(args[0].from, &rest);
- break;
+ case Opt_min_size:
+ /* memparse() will accept a K/M/G without a digit */
+ if (!isdigit(param->string[0]))
+ goto bad_val;
+ ctx->min_size_opt = memparse(param->string, &rest);
+ ctx->min_val_type = SIZE_STD;
+ if (*rest == '%')
+ ctx->min_val_type = SIZE_PERCENT;
+ return 0;
- case Opt_pagesize: {
- unsigned long ps;
- ps = memparse(args[0].from, &rest);
- pconfig->hstate = size_to_hstate(ps);
- if (!pconfig->hstate) {
- pr_err("Unsupported page size %lu MB\n",
- ps >> 20);
- return -EINVAL;
- }
- break;
- }
+ default:
+ return -EINVAL;
+ }
- case Opt_min_size: {
- /* memparse() will accept a K/M/G without a digit */
- if (!isdigit(*args[0].from))
- goto bad_val;
- min_size_opt = memparse(args[0].from, &rest);
- min_val_type = SIZE_STD;
- if (*rest == '%')
- min_val_type = SIZE_PERCENT;
- break;
- }
+bad_val:
+ return invalf(fc, "hugetlbfs: Bad value '%s' for mount option '%s'\n",
+ param->string, param->key);
+}
- default:
- pr_err("Bad mount option: \"%s\"\n", p);
- return -EINVAL;
- break;
- }
- }
+/*
+ * Validate the parsed options.
+ */
+static int hugetlbfs_validate(struct fs_context *fc)
+{
+ struct hugetlbfs_fs_context *ctx = fc->fs_private;
/*
* Use huge page pool size (in hstate) to convert the size
* options to number of huge pages. If NO_SIZE, -1 is returned.
*/
- pconfig->max_hpages = hugetlbfs_size_to_hpages(pconfig->hstate,
- max_size_opt, max_val_type);
- pconfig->min_hpages = hugetlbfs_size_to_hpages(pconfig->hstate,
- min_size_opt, min_val_type);
+ ctx->max_hpages = hugetlbfs_size_to_hpages(ctx->hstate,
+ ctx->max_size_opt,
+ ctx->max_val_type);
+ ctx->min_hpages = hugetlbfs_size_to_hpages(ctx->hstate,
+ ctx->min_size_opt,
+ ctx->min_val_type);
/*
* If max_size was specified, then min_size must be smaller
*/
- if (max_val_type > NO_SIZE &&
- pconfig->min_hpages > pconfig->max_hpages) {
- pr_err("minimum size can not be greater than maximum size\n");
+ if (ctx->max_val_type > NO_SIZE &&
+ ctx->min_hpages > ctx->max_hpages) {
+ pr_err("Minimum size can not be greater than maximum size\n");
return -EINVAL;
}
return 0;
-
-bad_val:
- pr_err("Bad value '%s' for mount option '%s'\n", args[0].from, p);
- return -EINVAL;
}
static int
-hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
+hugetlbfs_fill_super(struct super_block *sb, struct fs_context *fc)
{
- int ret;
- struct hugetlbfs_config config;
+ struct hugetlbfs_fs_context *ctx = fc->fs_private;
struct hugetlbfs_sb_info *sbinfo;
- config.max_hpages = -1; /* No limit on size by default */
- config.nr_inodes = -1; /* No limit on number of inodes by default */
- config.uid = current_fsuid();
- config.gid = current_fsgid();
- config.mode = 0755;
- config.hstate = &default_hstate;
- config.min_hpages = -1; /* No default minimum size */
- ret = hugetlbfs_parse_options(data, &config);
- if (ret)
- return ret;
-
sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
if (!sbinfo)
return -ENOMEM;
sb->s_fs_info = sbinfo;
- sbinfo->hstate = config.hstate;
spin_lock_init(&sbinfo->stat_lock);
- sbinfo->max_inodes = config.nr_inodes;
- sbinfo->free_inodes = config.nr_inodes;
- sbinfo->spool = NULL;
- sbinfo->uid = config.uid;
- sbinfo->gid = config.gid;
- sbinfo->mode = config.mode;
+ sbinfo->hstate = ctx->hstate;
+ sbinfo->max_inodes = ctx->nr_inodes;
+ sbinfo->free_inodes = ctx->nr_inodes;
+ sbinfo->spool = NULL;
+ sbinfo->uid = ctx->uid;
+ sbinfo->gid = ctx->gid;
+ sbinfo->mode = ctx->mode;
/*
* Allocate and initialize subpool if maximum or minimum size is
* specified. Any needed reservations (for minimim size) are taken
* taken when the subpool is created.
*/
- if (config.max_hpages != -1 || config.min_hpages != -1) {
- sbinfo->spool = hugepage_new_subpool(config.hstate,
- config.max_hpages,
- config.min_hpages);
+ if (ctx->max_hpages != -1 || ctx->min_hpages != -1) {
+ sbinfo->spool = hugepage_new_subpool(ctx->hstate,
+ ctx->max_hpages,
+ ctx->min_hpages);
if (!sbinfo->spool)
goto out_free;
}
sb->s_maxbytes = MAX_LFS_FILESIZE;
- sb->s_blocksize = huge_page_size(config.hstate);
- sb->s_blocksize_bits = huge_page_shift(config.hstate);
+ sb->s_blocksize = huge_page_size(ctx->hstate);
+ sb->s_blocksize_bits = huge_page_shift(ctx->hstate);
sb->s_magic = HUGETLBFS_MAGIC;
sb->s_op = &hugetlbfs_ops;
sb->s_time_gran = 1;
- sb->s_root = d_make_root(hugetlbfs_get_root(sb, &config));
+ sb->s_root = d_make_root(hugetlbfs_get_root(sb, ctx));
if (!sb->s_root)
goto out_free;
return 0;
@@ -1290,16 +1283,52 @@ out_free:
return -ENOMEM;
}
-static struct dentry *hugetlbfs_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
+static int hugetlbfs_get_tree(struct fs_context *fc)
+{
+ int err = hugetlbfs_validate(fc);
+ if (err)
+ return err;
+ return vfs_get_super(fc, vfs_get_independent_super, hugetlbfs_fill_super);
+}
+
+static void hugetlbfs_fs_context_free(struct fs_context *fc)
+{
+ kfree(fc->fs_private);
+}
+
+static const struct fs_context_operations hugetlbfs_fs_context_ops = {
+ .free = hugetlbfs_fs_context_free,
+ .parse_param = hugetlbfs_parse_param,
+ .get_tree = hugetlbfs_get_tree,
+};
+
+static int hugetlbfs_init_fs_context(struct fs_context *fc)
{
- return mount_nodev(fs_type, flags, data, hugetlbfs_fill_super);
+ struct hugetlbfs_fs_context *ctx;
+
+ ctx = kzalloc(sizeof(struct hugetlbfs_fs_context), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->max_hpages = -1; /* No limit on size by default */
+ ctx->nr_inodes = -1; /* No limit on number of inodes by default */
+ ctx->uid = current_fsuid();
+ ctx->gid = current_fsgid();
+ ctx->mode = 0755;
+ ctx->hstate = &default_hstate;
+ ctx->min_hpages = -1; /* No default minimum size */
+ ctx->max_val_type = NO_SIZE;
+ ctx->min_val_type = NO_SIZE;
+ fc->fs_private = ctx;
+ fc->ops = &hugetlbfs_fs_context_ops;
+ return 0;
}
static struct file_system_type hugetlbfs_fs_type = {
- .name = "hugetlbfs",
- .mount = hugetlbfs_mount,
- .kill_sb = kill_litter_super,
+ .name = "hugetlbfs",
+ .init_fs_context = hugetlbfs_init_fs_context,
+ .parameters = &hugetlb_fs_parameters,
+ .kill_sb = kill_litter_super,
};
static struct vfsmount *hugetlbfs_vfsmount[HUGE_MAX_HSTATE];
@@ -1384,8 +1413,29 @@ out:
return file;
}
+static struct vfsmount *__init mount_one_hugetlbfs(struct hstate *h)
+{
+ struct fs_context *fc;
+ struct vfsmount *mnt;
+
+ fc = fs_context_for_mount(&hugetlbfs_fs_type, SB_KERNMOUNT);
+ if (IS_ERR(fc)) {
+ mnt = ERR_CAST(fc);
+ } else {
+ struct hugetlbfs_fs_context *ctx = fc->fs_private;
+ ctx->hstate = h;
+ mnt = fc_mount(fc);
+ put_fs_context(fc);
+ }
+ if (IS_ERR(mnt))
+ pr_err("Cannot mount internal hugetlbfs for page size %uK",
+ 1U << (h->order + PAGE_SHIFT - 10));
+ return mnt;
+}
+
static int __init init_hugetlbfs_fs(void)
{
+ struct vfsmount *mnt;
struct hstate *h;
int error;
int i;
@@ -1408,24 +1458,16 @@ static int __init init_hugetlbfs_fs(void)
i = 0;
for_each_hstate(h) {
- char buf[50];
- unsigned ps_kb = 1U << (h->order + PAGE_SHIFT - 10);
-
- snprintf(buf, sizeof(buf), "pagesize=%uK", ps_kb);
- hugetlbfs_vfsmount[i] = kern_mount_data(&hugetlbfs_fs_type,
- buf);
-
- if (IS_ERR(hugetlbfs_vfsmount[i])) {
- pr_err("Cannot mount internal hugetlbfs for "
- "page size %uK", ps_kb);
- error = PTR_ERR(hugetlbfs_vfsmount[i]);
- hugetlbfs_vfsmount[i] = NULL;
+ mnt = mount_one_hugetlbfs(h);
+ if (IS_ERR(mnt) && i == 0) {
+ error = PTR_ERR(mnt);
+ goto out;
}
+ hugetlbfs_vfsmount[i] = mnt;
i++;
}
- /* Non default hstates are optional */
- if (!IS_ERR_OR_NULL(hugetlbfs_vfsmount[default_hstate_idx]))
- return 0;
+
+ return 0;
out:
kmem_cache_destroy(hugetlbfs_inode_cachep);
diff --git a/fs/internal.h b/fs/internal.h
index d410186bc369..6a8b71643af4 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -17,6 +17,7 @@ struct linux_binprm;
struct path;
struct mount;
struct shrink_control;
+struct fs_context;
/*
* block_dev.c
@@ -52,8 +53,16 @@ int __generic_write_end(struct inode *inode, loff_t pos, unsigned copied,
extern void __init chrdev_init(void);
/*
+ * fs_context.c
+ */
+extern int parse_monolithic_mount_data(struct fs_context *, void *);
+extern void fc_drop_locked(struct fs_context *);
+
+/*
* namei.c
*/
+extern int filename_lookup(int dfd, struct filename *name, unsigned flags,
+ struct path *path, struct path *root);
extern int user_path_mountpoint_at(int, const char __user *, unsigned int, struct path *);
extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
const char *, unsigned int, struct path *);
@@ -99,10 +108,8 @@ extern struct file *alloc_empty_file_noaccount(int, const struct cred *);
/*
* super.c
*/
-extern int do_remount_sb(struct super_block *, int, void *, int);
+extern int reconfigure_super(struct fs_context *);
extern bool trylock_super(struct super_block *sb);
-extern struct dentry *mount_fs(struct file_system_type *,
- int, const char *, void *);
extern struct super_block *user_get_super(dev_t);
/*
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index dba810cd83b1..0b7d197a904c 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -17,6 +17,7 @@
#include <linux/xattr.h>
#include <linux/kernfs.h>
+#include <linux/fs_context.h>
struct kernfs_iattrs {
struct iattr ia_iattr;
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index f3ac352699cf..9a4646eecb71 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -22,16 +22,6 @@
struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
-static int kernfs_sop_remount_fs(struct super_block *sb, int *flags, char *data)
-{
- struct kernfs_root *root = kernfs_info(sb)->root;
- struct kernfs_syscall_ops *scops = root->syscall_ops;
-
- if (scops && scops->remount_fs)
- return scops->remount_fs(root, flags, data);
- return 0;
-}
-
static int kernfs_sop_show_options(struct seq_file *sf, struct dentry *dentry)
{
struct kernfs_root *root = kernfs_root(kernfs_dentry_node(dentry));
@@ -60,7 +50,6 @@ const struct super_operations kernfs_sops = {
.drop_inode = generic_delete_inode,
.evict_inode = kernfs_evict_inode,
- .remount_fs = kernfs_sop_remount_fs,
.show_options = kernfs_sop_show_options,
.show_path = kernfs_sop_show_path,
};
@@ -222,7 +211,7 @@ struct dentry *kernfs_node_dentry(struct kernfs_node *kn,
} while (true);
}
-static int kernfs_fill_super(struct super_block *sb, unsigned long magic)
+static int kernfs_fill_super(struct super_block *sb, struct kernfs_fs_context *kfc)
{
struct kernfs_super_info *info = kernfs_info(sb);
struct inode *inode;
@@ -233,7 +222,7 @@ static int kernfs_fill_super(struct super_block *sb, unsigned long magic)
sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV;
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
- sb->s_magic = magic;
+ sb->s_magic = kfc->magic;
sb->s_op = &kernfs_sops;
sb->s_xattr = kernfs_xattr_handlers;
if (info->root->flags & KERNFS_ROOT_SUPPORT_EXPORTOP)
@@ -263,21 +252,20 @@ static int kernfs_fill_super(struct super_block *sb, unsigned long magic)
return 0;
}
-static int kernfs_test_super(struct super_block *sb, void *data)
+static int kernfs_test_super(struct super_block *sb, struct fs_context *fc)
{
struct kernfs_super_info *sb_info = kernfs_info(sb);
- struct kernfs_super_info *info = data;
+ struct kernfs_super_info *info = fc->s_fs_info;
return sb_info->root == info->root && sb_info->ns == info->ns;
}
-static int kernfs_set_super(struct super_block *sb, void *data)
+static int kernfs_set_super(struct super_block *sb, struct fs_context *fc)
{
- int error;
- error = set_anon_super(sb, data);
- if (!error)
- sb->s_fs_info = data;
- return error;
+ struct kernfs_fs_context *kfc = fc->fs_private;
+
+ kfc->ns_tag = NULL;
+ return set_anon_super_fc(sb, fc);
}
/**
@@ -294,63 +282,60 @@ const void *kernfs_super_ns(struct super_block *sb)
}
/**
- * kernfs_mount_ns - kernfs mount helper
- * @fs_type: file_system_type of the fs being mounted
- * @flags: mount flags specified for the mount
- * @root: kernfs_root of the hierarchy being mounted
- * @magic: file system specific magic number
- * @new_sb_created: tell the caller if we allocated a new superblock
- * @ns: optional namespace tag of the mount
+ * kernfs_get_tree - kernfs filesystem access/retrieval helper
+ * @fc: The filesystem context.
*
- * This is to be called from each kernfs user's file_system_type->mount()
- * implementation, which should pass through the specified @fs_type and
- * @flags, and specify the hierarchy and namespace tag to mount via @root
- * and @ns, respectively.
- *
- * The return value can be passed to the vfs layer verbatim.
+ * This is to be called from each kernfs user's fs_context->ops->get_tree()
+ * implementation, which should set the specified ->@fs_type and ->@flags, and
+ * specify the hierarchy and namespace tag to mount via ->@root and ->@ns,
+ * respectively.
*/
-struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags,
- struct kernfs_root *root, unsigned long magic,
- bool *new_sb_created, const void *ns)
+int kernfs_get_tree(struct fs_context *fc)
{
+ struct kernfs_fs_context *kfc = fc->fs_private;
struct super_block *sb;
struct kernfs_super_info *info;
int error;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
- return ERR_PTR(-ENOMEM);
+ return -ENOMEM;
- info->root = root;
- info->ns = ns;
+ info->root = kfc->root;
+ info->ns = kfc->ns_tag;
INIT_LIST_HEAD(&info->node);
- sb = sget_userns(fs_type, kernfs_test_super, kernfs_set_super, flags,
- &init_user_ns, info);
- if (IS_ERR(sb) || sb->s_fs_info != info)
- kfree(info);
+ fc->s_fs_info = info;
+ sb = sget_fc(fc, kernfs_test_super, kernfs_set_super);
if (IS_ERR(sb))
- return ERR_CAST(sb);
-
- if (new_sb_created)
- *new_sb_created = !sb->s_root;
+ return PTR_ERR(sb);
if (!sb->s_root) {
struct kernfs_super_info *info = kernfs_info(sb);
- error = kernfs_fill_super(sb, magic);
+ kfc->new_sb_created = true;
+
+ error = kernfs_fill_super(sb, kfc);
if (error) {
deactivate_locked_super(sb);
- return ERR_PTR(error);
+ return error;
}
sb->s_flags |= SB_ACTIVE;
mutex_lock(&kernfs_mutex);
- list_add(&info->node, &root->supers);
+ list_add(&info->node, &info->root->supers);
mutex_unlock(&kernfs_mutex);
}
- return dget(sb->s_root);
+ fc->root = dget(sb->s_root);
+ return 0;
+}
+
+void kernfs_free_fs_context(struct fs_context *fc)
+{
+ /* Note that we don't deal with kfc->ns_tag here. */
+ kfree(fc->s_fs_info);
+ fc->s_fs_info = NULL;
}
/**
@@ -377,36 +362,6 @@ void kernfs_kill_sb(struct super_block *sb)
kfree(info);
}
-/**
- * kernfs_pin_sb: try to pin the superblock associated with a kernfs_root
- * @kernfs_root: the kernfs_root in question
- * @ns: the namespace tag
- *
- * Pin the superblock so the superblock won't be destroyed in subsequent
- * operations. This can be used to block ->kill_sb() which may be useful
- * for kernfs users which dynamically manage superblocks.
- *
- * Returns NULL if there's no superblock associated to this kernfs_root, or
- * -EINVAL if the superblock is being freed.
- */
-struct super_block *kernfs_pin_sb(struct kernfs_root *root, const void *ns)
-{
- struct kernfs_super_info *info;
- struct super_block *sb = NULL;
-
- mutex_lock(&kernfs_mutex);
- list_for_each_entry(info, &root->supers, node) {
- if (info->ns == ns) {
- sb = info->sb;
- if (!atomic_inc_not_zero(&info->sb->s_active))
- sb = ERR_PTR(-EINVAL);
- break;
- }
- }
- mutex_unlock(&kernfs_mutex);
- return sb;
-}
-
void __init kernfs_init(void)
{
diff --git a/fs/mount.h b/fs/mount.h
index f39bc9da4d73..6250de544760 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -146,3 +146,8 @@ static inline bool is_local_mountpoint(struct dentry *dentry)
return __is_local_mountpoint(dentry);
}
+
+static inline bool is_anon_ns(struct mnt_namespace *ns)
+{
+ return ns->seq == 0;
+}
diff --git a/fs/namei.c b/fs/namei.c
index 3662a09830be..dede0147b3f6 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2331,8 +2331,8 @@ static int path_lookupat(struct nameidata *nd, unsigned flags, struct path *path
return err;
}
-static int filename_lookup(int dfd, struct filename *name, unsigned flags,
- struct path *path, struct path *root)
+int filename_lookup(int dfd, struct filename *name, unsigned flags,
+ struct path *path, struct path *root)
{
int retval;
struct nameidata nd;
diff --git a/fs/namespace.c b/fs/namespace.c
index 98a8c182af4f..c9cab307fa77 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -27,6 +27,7 @@
#include <linux/task_work.h>
#include <linux/sched/task.h>
#include <uapi/linux/mount.h>
+#include <linux/fs_context.h>
#include "pnode.h"
#include "internal.h"
@@ -940,38 +941,81 @@ static struct mount *skip_mnt_tree(struct mount *p)
return p;
}
-struct vfsmount *
-vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data)
+/**
+ * vfs_create_mount - Create a mount for a configured superblock
+ * @fc: The configuration context with the superblock attached
+ *
+ * Create a mount to an already configured superblock. If necessary, the
+ * caller should invoke vfs_get_tree() before calling this.
+ *
+ * Note that this does not attach the mount to anything.
+ */
+struct vfsmount *vfs_create_mount(struct fs_context *fc)
{
struct mount *mnt;
- struct dentry *root;
- if (!type)
- return ERR_PTR(-ENODEV);
+ if (!fc->root)
+ return ERR_PTR(-EINVAL);
- mnt = alloc_vfsmnt(name);
+ mnt = alloc_vfsmnt(fc->source ?: "none");
if (!mnt)
return ERR_PTR(-ENOMEM);
- if (flags & SB_KERNMOUNT)
+ if (fc->sb_flags & SB_KERNMOUNT)
mnt->mnt.mnt_flags = MNT_INTERNAL;
- root = mount_fs(type, flags, name, data);
- if (IS_ERR(root)) {
- mnt_free_id(mnt);
- free_vfsmnt(mnt);
- return ERR_CAST(root);
- }
+ atomic_inc(&fc->root->d_sb->s_active);
+ mnt->mnt.mnt_sb = fc->root->d_sb;
+ mnt->mnt.mnt_root = dget(fc->root);
+ mnt->mnt_mountpoint = mnt->mnt.mnt_root;
+ mnt->mnt_parent = mnt;
- mnt->mnt.mnt_root = root;
- mnt->mnt.mnt_sb = root->d_sb;
- mnt->mnt_mountpoint = mnt->mnt.mnt_root;
- mnt->mnt_parent = mnt;
lock_mount_hash();
- list_add_tail(&mnt->mnt_instance, &root->d_sb->s_mounts);
+ list_add_tail(&mnt->mnt_instance, &mnt->mnt.mnt_sb->s_mounts);
unlock_mount_hash();
return &mnt->mnt;
}
+EXPORT_SYMBOL(vfs_create_mount);
+
+struct vfsmount *fc_mount(struct fs_context *fc)
+{
+ int err = vfs_get_tree(fc);
+ if (!err) {
+ up_write(&fc->root->d_sb->s_umount);
+ return vfs_create_mount(fc);
+ }
+ return ERR_PTR(err);
+}
+EXPORT_SYMBOL(fc_mount);
+
+struct vfsmount *vfs_kern_mount(struct file_system_type *type,
+ int flags, const char *name,
+ void *data)
+{
+ struct fs_context *fc;
+ struct vfsmount *mnt;
+ int ret = 0;
+
+ if (!type)
+ return ERR_PTR(-EINVAL);
+
+ fc = fs_context_for_mount(type, flags);
+ if (IS_ERR(fc))
+ return ERR_CAST(fc);
+
+ if (name)
+ ret = vfs_parse_fs_string(fc, "source",
+ name, strlen(name));
+ if (!ret)
+ ret = parse_monolithic_mount_data(fc, data);
+ if (!ret)
+ mnt = fc_mount(fc);
+ else
+ mnt = ERR_PTR(ret);
+
+ put_fs_context(fc);
+ return mnt;
+}
EXPORT_SYMBOL_GPL(vfs_kern_mount);
struct vfsmount *
@@ -1013,27 +1057,6 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root,
mnt->mnt.mnt_flags = old->mnt.mnt_flags;
mnt->mnt.mnt_flags &= ~(MNT_WRITE_HOLD|MNT_MARKED|MNT_INTERNAL);
- /* Don't allow unprivileged users to change mount flags */
- if (flag & CL_UNPRIVILEGED) {
- mnt->mnt.mnt_flags |= MNT_LOCK_ATIME;
-
- if (mnt->mnt.mnt_flags & MNT_READONLY)
- mnt->mnt.mnt_flags |= MNT_LOCK_READONLY;
-
- if (mnt->mnt.mnt_flags & MNT_NODEV)
- mnt->mnt.mnt_flags |= MNT_LOCK_NODEV;
-
- if (mnt->mnt.mnt_flags & MNT_NOSUID)
- mnt->mnt.mnt_flags |= MNT_LOCK_NOSUID;
-
- if (mnt->mnt.mnt_flags & MNT_NOEXEC)
- mnt->mnt.mnt_flags |= MNT_LOCK_NOEXEC;
- }
-
- /* Don't allow unprivileged users to reveal what is under a mount */
- if ((flag & CL_UNPRIVILEGED) &&
- (!(flag & CL_EXPIRE) || list_empty(&old->mnt_expire)))
- mnt->mnt.mnt_flags |= MNT_LOCKED;
atomic_inc(&sb->s_active);
mnt->mnt.mnt_sb = sb;
@@ -1464,6 +1487,29 @@ static void umount_tree(struct mount *mnt, enum umount_tree_flags how)
static void shrink_submounts(struct mount *mnt);
+static int do_umount_root(struct super_block *sb)
+{
+ int ret = 0;
+
+ down_write(&sb->s_umount);
+ if (!sb_rdonly(sb)) {
+ struct fs_context *fc;
+
+ fc = fs_context_for_reconfigure(sb->s_root, SB_RDONLY,
+ SB_RDONLY);
+ if (IS_ERR(fc)) {
+ ret = PTR_ERR(fc);
+ } else {
+ ret = parse_monolithic_mount_data(fc, NULL);
+ if (!ret)
+ ret = reconfigure_super(fc);
+ put_fs_context(fc);
+ }
+ }
+ up_write(&sb->s_umount);
+ return ret;
+}
+
static int do_umount(struct mount *mnt, int flags)
{
struct super_block *sb = mnt->mnt.mnt_sb;
@@ -1529,11 +1575,7 @@ static int do_umount(struct mount *mnt, int flags)
*/
if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
return -EPERM;
- down_write(&sb->s_umount);
- if (!sb_rdonly(sb))
- retval = do_remount_sb(sb, SB_RDONLY, NULL, 0);
- up_write(&sb->s_umount);
- return retval;
+ return do_umount_root(sb);
}
namespace_lock();
@@ -1839,6 +1881,33 @@ int iterate_mounts(int (*f)(struct vfsmount *, void *), void *arg,
return 0;
}
+static void lock_mnt_tree(struct mount *mnt)
+{
+ struct mount *p;
+
+ for (p = mnt; p; p = next_mnt(p, mnt)) {
+ int flags = p->mnt.mnt_flags;
+ /* Don't allow unprivileged users to change mount flags */
+ flags |= MNT_LOCK_ATIME;
+
+ if (flags & MNT_READONLY)
+ flags |= MNT_LOCK_READONLY;
+
+ if (flags & MNT_NODEV)
+ flags |= MNT_LOCK_NODEV;
+
+ if (flags & MNT_NOSUID)
+ flags |= MNT_LOCK_NOSUID;
+
+ if (flags & MNT_NOEXEC)
+ flags |= MNT_LOCK_NOEXEC;
+ /* Don't allow unprivileged users to reveal what is under a mount */
+ if (list_empty(&p->mnt_expire))
+ flags |= MNT_LOCKED;
+ p->mnt.mnt_flags = flags;
+ }
+}
+
static void cleanup_group_ids(struct mount *mnt, struct mount *end)
{
struct mount *p;
@@ -1956,6 +2025,7 @@ static int attach_recursive_mnt(struct mount *source_mnt,
struct mountpoint *dest_mp,
struct path *parent_path)
{
+ struct user_namespace *user_ns = current->nsproxy->mnt_ns->user_ns;
HLIST_HEAD(tree_list);
struct mnt_namespace *ns = dest_mnt->mnt_ns;
struct mountpoint *smp;
@@ -2006,6 +2076,9 @@ static int attach_recursive_mnt(struct mount *source_mnt,
child->mnt_mountpoint);
if (q)
mnt_change_mountpoint(child, smp, q);
+ /* Notice when we are propagating across user namespaces */
+ if (child->mnt_parent->mnt_ns->user_ns != user_ns)
+ lock_mnt_tree(child);
commit_tree(child);
}
put_mountpoint(smp);
@@ -2313,7 +2386,7 @@ static int do_remount(struct path *path, int ms_flags, int sb_flags,
int err;
struct super_block *sb = path->mnt->mnt_sb;
struct mount *mnt = real_mount(path->mnt);
- void *sec_opts = NULL;
+ struct fs_context *fc;
if (!check_mnt(mnt))
return -EINVAL;
@@ -2324,24 +2397,22 @@ static int do_remount(struct path *path, int ms_flags, int sb_flags,
if (!can_change_locked_flags(mnt, mnt_flags))
return -EPERM;
- if (data && !(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)) {
- err = security_sb_eat_lsm_opts(data, &sec_opts);
- if (err)
- return err;
- }
- err = security_sb_remount(sb, sec_opts);
- security_free_mnt_opts(&sec_opts);
- if (err)
- return err;
+ fc = fs_context_for_reconfigure(path->dentry, sb_flags, MS_RMT_MASK);
+ if (IS_ERR(fc))
+ return PTR_ERR(fc);
- down_write(&sb->s_umount);
- err = -EPERM;
- if (ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) {
- err = do_remount_sb(sb, sb_flags, data, 0);
- if (!err)
- set_mount_attributes(mnt, mnt_flags);
+ err = parse_monolithic_mount_data(fc, data);
+ if (!err) {
+ down_write(&sb->s_umount);
+ err = -EPERM;
+ if (ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) {
+ err = reconfigure_super(fc);
+ if (!err)
+ set_mount_attributes(mnt, mnt_flags);
+ }
+ up_write(&sb->s_umount);
}
- up_write(&sb->s_umount);
+ put_fs_context(fc);
return err;
}
@@ -2425,29 +2496,6 @@ out:
return err;
}
-static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype)
-{
- int err;
- const char *subtype = strchr(fstype, '.');
- if (subtype) {
- subtype++;
- err = -EINVAL;
- if (!subtype[0])
- goto err;
- } else
- subtype = "";
-
- mnt->mnt_sb->s_subtype = kstrdup(subtype, GFP_KERNEL);
- err = -ENOMEM;
- if (!mnt->mnt_sb->s_subtype)
- goto err;
- return mnt;
-
- err:
- mntput(mnt);
- return ERR_PTR(err);
-}
-
/*
* add a mount into a namespace's mount tree
*/
@@ -2492,7 +2540,39 @@ unlock:
return err;
}
-static bool mount_too_revealing(struct vfsmount *mnt, int *new_mnt_flags);
+static bool mount_too_revealing(const struct super_block *sb, int *new_mnt_flags);
+
+/*
+ * Create a new mount using a superblock configuration and request it
+ * be added to the namespace tree.
+ */
+static int do_new_mount_fc(struct fs_context *fc, struct path *mountpoint,
+ unsigned int mnt_flags)
+{
+ struct vfsmount *mnt;
+ struct super_block *sb = fc->root->d_sb;
+ int error;
+
+ error = security_sb_kern_mount(sb);
+ if (!error && mount_too_revealing(sb, &mnt_flags))
+ error = -EPERM;
+
+ if (unlikely(error)) {
+ fc_drop_locked(fc);
+ return error;
+ }
+
+ up_write(&sb->s_umount);
+
+ mnt = vfs_create_mount(fc);
+ if (IS_ERR(mnt))
+ return PTR_ERR(mnt);
+
+ error = do_add_mount(real_mount(mnt), mountpoint, mnt_flags);
+ if (error < 0)
+ mntput(mnt);
+ return error;
+}
/*
* create a new mount for userspace and request it to be added into the
@@ -2502,8 +2582,9 @@ static int do_new_mount(struct path *path, const char *fstype, int sb_flags,
int mnt_flags, const char *name, void *data)
{
struct file_system_type *type;
- struct vfsmount *mnt;
- int err;
+ struct fs_context *fc;
+ const char *subtype = NULL;
+ int err = 0;
if (!fstype)
return -EINVAL;
@@ -2512,23 +2593,37 @@ static int do_new_mount(struct path *path, const char *fstype, int sb_flags,
if (!type)
return -ENODEV;
- mnt = vfs_kern_mount(type, sb_flags, name, data);
- if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) &&
- !mnt->mnt_sb->s_subtype)
- mnt = fs_set_subtype(mnt, fstype);
+ if (type->fs_flags & FS_HAS_SUBTYPE) {
+ subtype = strchr(fstype, '.');
+ if (subtype) {
+ subtype++;
+ if (!*subtype) {
+ put_filesystem(type);
+ return -EINVAL;
+ }
+ } else {
+ subtype = "";
+ }
+ }
+ fc = fs_context_for_mount(type, sb_flags);
put_filesystem(type);
- if (IS_ERR(mnt))
- return PTR_ERR(mnt);
-
- if (mount_too_revealing(mnt, &mnt_flags)) {
- mntput(mnt);
- return -EPERM;
- }
+ if (IS_ERR(fc))
+ return PTR_ERR(fc);
+
+ if (subtype)
+ err = vfs_parse_fs_string(fc, "subtype",
+ subtype, strlen(subtype));
+ if (!err && name)
+ err = vfs_parse_fs_string(fc, "source", name, strlen(name));
+ if (!err)
+ err = parse_monolithic_mount_data(fc, data);
+ if (!err)
+ err = vfs_get_tree(fc);
+ if (!err)
+ err = do_new_mount_fc(fc, path, mnt_flags);
- err = do_add_mount(real_mount(mnt), path, mnt_flags);
- if (err)
- mntput(mnt);
+ put_fs_context(fc);
return err;
}
@@ -2863,7 +2958,8 @@ static void dec_mnt_namespaces(struct ucounts *ucounts)
static void free_mnt_ns(struct mnt_namespace *ns)
{
- ns_free_inum(&ns->ns);
+ if (!is_anon_ns(ns))
+ ns_free_inum(&ns->ns);
dec_mnt_namespaces(ns->ucounts);
put_user_ns(ns->user_ns);
kfree(ns);
@@ -2878,7 +2974,7 @@ static void free_mnt_ns(struct mnt_namespace *ns)
*/
static atomic64_t mnt_ns_seq = ATOMIC64_INIT(1);
-static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns)
+static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns, bool anon)
{
struct mnt_namespace *new_ns;
struct ucounts *ucounts;
@@ -2888,28 +2984,27 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns)
if (!ucounts)
return ERR_PTR(-ENOSPC);
- new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
+ new_ns = kzalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
if (!new_ns) {
dec_mnt_namespaces(ucounts);
return ERR_PTR(-ENOMEM);
}
- ret = ns_alloc_inum(&new_ns->ns);
- if (ret) {
- kfree(new_ns);
- dec_mnt_namespaces(ucounts);
- return ERR_PTR(ret);
+ if (!anon) {
+ ret = ns_alloc_inum(&new_ns->ns);
+ if (ret) {
+ kfree(new_ns);
+ dec_mnt_namespaces(ucounts);
+ return ERR_PTR(ret);
+ }
}
new_ns->ns.ops = &mntns_operations;
- new_ns->seq = atomic64_add_return(1, &mnt_ns_seq);
+ if (!anon)
+ new_ns->seq = atomic64_add_return(1, &mnt_ns_seq);
atomic_set(&new_ns->count, 1);
- new_ns->root = NULL;
INIT_LIST_HEAD(&new_ns->list);
init_waitqueue_head(&new_ns->poll);
- new_ns->event = 0;
new_ns->user_ns = get_user_ns(user_ns);
new_ns->ucounts = ucounts;
- new_ns->mounts = 0;
- new_ns->pending_mounts = 0;
return new_ns;
}
@@ -2933,7 +3028,7 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns,
old = ns->root;
- new_ns = alloc_mnt_ns(user_ns);
+ new_ns = alloc_mnt_ns(user_ns, false);
if (IS_ERR(new_ns))
return new_ns;
@@ -2941,13 +3036,18 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns,
/* First pass: copy the tree topology */
copy_flags = CL_COPY_UNBINDABLE | CL_EXPIRE;
if (user_ns != ns->user_ns)
- copy_flags |= CL_SHARED_TO_SLAVE | CL_UNPRIVILEGED;
+ copy_flags |= CL_SHARED_TO_SLAVE;
new = copy_tree(old, old->mnt.mnt_root, copy_flags);
if (IS_ERR(new)) {
namespace_unlock();
free_mnt_ns(new_ns);
return ERR_CAST(new);
}
+ if (user_ns != ns->user_ns) {
+ lock_mount_hash();
+ lock_mnt_tree(new);
+ unlock_mount_hash();
+ }
new_ns->root = new;
list_add_tail(&new_ns->list, &new->mnt_list);
@@ -2988,37 +3088,25 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns,
return new_ns;
}
-/**
- * create_mnt_ns - creates a private namespace and adds a root filesystem
- * @mnt: pointer to the new root filesystem mountpoint
- */
-static struct mnt_namespace *create_mnt_ns(struct vfsmount *m)
-{
- struct mnt_namespace *new_ns = alloc_mnt_ns(&init_user_ns);
- if (!IS_ERR(new_ns)) {
- struct mount *mnt = real_mount(m);
- mnt->mnt_ns = new_ns;
- new_ns->root = mnt;
- new_ns->mounts++;
- list_add(&mnt->mnt_list, &new_ns->list);
- } else {
- mntput(m);
- }
- return new_ns;
-}
-
-struct dentry *mount_subtree(struct vfsmount *mnt, const char *name)
+struct dentry *mount_subtree(struct vfsmount *m, const char *name)
{
+ struct mount *mnt = real_mount(m);
struct mnt_namespace *ns;
struct super_block *s;
struct path path;
int err;
- ns = create_mnt_ns(mnt);
- if (IS_ERR(ns))
+ ns = alloc_mnt_ns(&init_user_ns, true);
+ if (IS_ERR(ns)) {
+ mntput(m);
return ERR_CAST(ns);
+ }
+ mnt->mnt_ns = ns;
+ ns->root = mnt;
+ ns->mounts++;
+ list_add(&mnt->mnt_list, &ns->list);
- err = vfs_path_lookup(mnt->mnt_root, mnt,
+ err = vfs_path_lookup(m->mnt_root, m,
name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
put_mnt_ns(ns);
@@ -3228,6 +3316,7 @@ out0:
static void __init init_mount_tree(void)
{
struct vfsmount *mnt;
+ struct mount *m;
struct mnt_namespace *ns;
struct path root;
struct file_system_type *type;
@@ -3240,10 +3329,14 @@ static void __init init_mount_tree(void)
if (IS_ERR(mnt))
panic("Can't create rootfs");
- ns = create_mnt_ns(mnt);
+ ns = alloc_mnt_ns(&init_user_ns, false);
if (IS_ERR(ns))
panic("Can't allocate initial namespace");
-
+ m = real_mount(mnt);
+ m->mnt_ns = ns;
+ ns->root = m;
+ ns->mounts = 1;
+ list_add(&m->mnt_list, &ns->list);
init_task.nsproxy->mnt_ns = ns;
get_mnt_ns(ns);
@@ -3297,10 +3390,10 @@ void put_mnt_ns(struct mnt_namespace *ns)
free_mnt_ns(ns);
}
-struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
+struct vfsmount *kern_mount(struct file_system_type *type)
{
struct vfsmount *mnt;
- mnt = vfs_kern_mount(type, SB_KERNMOUNT, type->name, data);
+ mnt = vfs_kern_mount(type, SB_KERNMOUNT, type->name, NULL);
if (!IS_ERR(mnt)) {
/*
* it is a longterm mount, don't release mnt until
@@ -3310,7 +3403,7 @@ struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
}
return mnt;
}
-EXPORT_SYMBOL_GPL(kern_mount_data);
+EXPORT_SYMBOL_GPL(kern_mount);
void kern_unmount(struct vfsmount *mnt)
{
@@ -3352,7 +3445,8 @@ bool current_chrooted(void)
return chrooted;
}
-static bool mnt_already_visible(struct mnt_namespace *ns, struct vfsmount *new,
+static bool mnt_already_visible(struct mnt_namespace *ns,
+ const struct super_block *sb,
int *new_mnt_flags)
{
int new_flags = *new_mnt_flags;
@@ -3364,7 +3458,7 @@ static bool mnt_already_visible(struct mnt_namespace *ns, struct vfsmount *new,
struct mount *child;
int mnt_flags;
- if (mnt->mnt.mnt_sb->s_type != new->mnt_sb->s_type)
+ if (mnt->mnt.mnt_sb->s_type != sb->s_type)
continue;
/* This mount is not fully visible if it's root directory
@@ -3415,7 +3509,7 @@ found:
return visible;
}
-static bool mount_too_revealing(struct vfsmount *mnt, int *new_mnt_flags)
+static bool mount_too_revealing(const struct super_block *sb, int *new_mnt_flags)
{
const unsigned long required_iflags = SB_I_NOEXEC | SB_I_NODEV;
struct mnt_namespace *ns = current->nsproxy->mnt_ns;
@@ -3425,7 +3519,7 @@ static bool mount_too_revealing(struct vfsmount *mnt, int *new_mnt_flags)
return false;
/* Can this filesystem be too revealing? */
- s_iflags = mnt->mnt_sb->s_iflags;
+ s_iflags = sb->s_iflags;
if (!(s_iflags & SB_I_USERNS_VISIBLE))
return false;
@@ -3435,7 +3529,7 @@ static bool mount_too_revealing(struct vfsmount *mnt, int *new_mnt_flags)
return true;
}
- return !mnt_already_visible(ns, mnt, new_mnt_flags);
+ return !mnt_already_visible(ns, sb, new_mnt_flags);
}
bool mnt_may_suid(struct vfsmount *mnt)
@@ -3484,6 +3578,9 @@ static int mntns_install(struct nsproxy *nsproxy, struct ns_common *ns)
!ns_capable(current_user_ns(), CAP_SYS_ADMIN))
return -EPERM;
+ if (is_anon_ns(mnt_ns))
+ return -EINVAL;
+
if (fs->users != 1)
return -EINVAL;
diff --git a/fs/pnode.c b/fs/pnode.c
index 1100e810d855..7ea6cfb65077 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -214,7 +214,6 @@ static struct mount *next_group(struct mount *m, struct mount *origin)
}
/* all accesses are serialized by namespace_sem */
-static struct user_namespace *user_ns;
static struct mount *last_dest, *first_source, *last_source, *dest_master;
static struct mountpoint *mp;
static struct hlist_head *list;
@@ -260,9 +259,6 @@ static int propagate_one(struct mount *m)
type |= CL_MAKE_SHARED;
}
- /* Notice when we are propagating across user namespaces */
- if (m->mnt_ns->user_ns != user_ns)
- type |= CL_UNPRIVILEGED;
child = copy_tree(last_source, last_source->mnt.mnt_root, type);
if (IS_ERR(child))
return PTR_ERR(child);
@@ -303,7 +299,6 @@ int propagate_mnt(struct mount *dest_mnt, struct mountpoint *dest_mp,
* propagate_one(); everything is serialized by namespace_sem,
* so globals will do just fine.
*/
- user_ns = current->nsproxy->mnt_ns->user_ns;
last_dest = dest_mnt;
first_source = source_mnt;
last_source = source_mnt;
diff --git a/fs/pnode.h b/fs/pnode.h
index dc87e65becd2..3960a83666cf 100644
--- a/fs/pnode.h
+++ b/fs/pnode.h
@@ -27,8 +27,7 @@
#define CL_MAKE_SHARED 0x08
#define CL_PRIVATE 0x10
#define CL_SHARED_TO_SLAVE 0x20
-#define CL_UNPRIVILEGED 0x40
-#define CL_COPY_MNT_NS_FILE 0x80
+#define CL_COPY_MNT_NS_FILE 0x40
#define CL_COPY_ALL (CL_COPY_UNBINDABLE | CL_COPY_MNT_NS_FILE)
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index da649ccd6804..fc7e38def174 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -24,7 +24,6 @@
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/mount.h>
-#include <linux/magic.h>
#include <linux/uaccess.h>
@@ -122,13 +121,12 @@ static int proc_show_options(struct seq_file *seq, struct dentry *root)
return 0;
}
-static const struct super_operations proc_sops = {
+const struct super_operations proc_sops = {
.alloc_inode = proc_alloc_inode,
.destroy_inode = proc_destroy_inode,
.drop_inode = generic_delete_inode,
.evict_inode = proc_evict_inode,
.statfs = simple_statfs,
- .remount_fs = proc_remount,
.show_options = proc_show_options,
};
@@ -488,51 +486,3 @@ struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de)
pde_put(de);
return inode;
}
-
-int proc_fill_super(struct super_block *s, void *data, int silent)
-{
- struct pid_namespace *ns = get_pid_ns(s->s_fs_info);
- struct inode *root_inode;
- int ret;
-
- if (!proc_parse_options(data, ns))
- return -EINVAL;
-
- /* User space would break if executables or devices appear on proc */
- s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC | SB_I_NODEV;
- s->s_flags |= SB_NODIRATIME | SB_NOSUID | SB_NOEXEC;
- s->s_blocksize = 1024;
- s->s_blocksize_bits = 10;
- s->s_magic = PROC_SUPER_MAGIC;
- s->s_op = &proc_sops;
- s->s_time_gran = 1;
-
- /*
- * procfs isn't actually a stacking filesystem; however, there is
- * too much magic going on inside it to permit stacking things on
- * top of it
- */
- s->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH;
-
- /* procfs dentries and inodes don't require IO to create */
- s->s_shrink.seeks = 0;
-
- pde_get(&proc_root);
- root_inode = proc_get_inode(s, &proc_root);
- if (!root_inode) {
- pr_err("proc_fill_super: get root inode failed\n");
- return -ENOMEM;
- }
-
- s->s_root = d_make_root(root_inode);
- if (!s->s_root) {
- pr_err("proc_fill_super: allocate dentry failed\n");
- return -ENOMEM;
- }
-
- ret = proc_setup_self(s);
- if (ret) {
- return ret;
- }
- return proc_setup_thread_self(s);
-}
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index ea575375f210..d1671e97f7fe 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -207,13 +207,12 @@ struct pde_opener {
struct completion *c;
} __randomize_layout;
extern const struct inode_operations proc_link_inode_operations;
-
extern const struct inode_operations proc_pid_link_inode_operations;
+extern const struct super_operations proc_sops;
void proc_init_kmemcache(void);
void set_proc_pid_nlink(void);
extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
-extern int proc_fill_super(struct super_block *, void *data, int flags);
extern void proc_entry_rundown(struct proc_dir_entry *);
/*
@@ -271,10 +270,8 @@ static inline void proc_tty_init(void) {}
* root.c
*/
extern struct proc_dir_entry proc_root;
-extern int proc_parse_options(char *options, struct pid_namespace *pid);
extern void proc_self_init(void);
-extern int proc_remount(struct super_block *, int *, char *);
/*
* task_[no]mmu.c
diff --git a/fs/proc/root.c b/fs/proc/root.c
index 621e6ec322ca..8b145e7b9661 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -19,86 +19,178 @@
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/user_namespace.h>
+#include <linux/fs_context.h>
#include <linux/mount.h>
#include <linux/pid_namespace.h>
-#include <linux/parser.h>
+#include <linux/fs_parser.h>
#include <linux/cred.h>
+#include <linux/magic.h>
+#include <linux/slab.h>
#include "internal.h"
-enum {
- Opt_gid, Opt_hidepid, Opt_err,
+struct proc_fs_context {
+ struct pid_namespace *pid_ns;
+ unsigned int mask;
+ int hidepid;
+ int gid;
};
-static const match_table_t tokens = {
- {Opt_hidepid, "hidepid=%u"},
- {Opt_gid, "gid=%u"},
- {Opt_err, NULL},
+enum proc_param {
+ Opt_gid,
+ Opt_hidepid,
};
-int proc_parse_options(char *options, struct pid_namespace *pid)
+static const struct fs_parameter_spec proc_param_specs[] = {
+ fsparam_u32("gid", Opt_gid),
+ fsparam_u32("hidepid", Opt_hidepid),
+ {}
+};
+
+static const struct fs_parameter_description proc_fs_parameters = {
+ .name = "proc",
+ .specs = proc_param_specs,
+};
+
+static int proc_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
- char *p;
- substring_t args[MAX_OPT_ARGS];
- int option;
-
- if (!options)
- return 1;
-
- while ((p = strsep(&options, ",")) != NULL) {
- int token;
- if (!*p)
- continue;
-
- args[0].to = args[0].from = NULL;
- token = match_token(p, tokens, args);
- switch (token) {
- case Opt_gid:
- if (match_int(&args[0], &option))
- return 0;
- pid->pid_gid = make_kgid(current_user_ns(), option);
- break;
- case Opt_hidepid:
- if (match_int(&args[0], &option))
- return 0;
- if (option < HIDEPID_OFF ||
- option > HIDEPID_INVISIBLE) {
- pr_err("proc: hidepid value must be between 0 and 2.\n");
- return 0;
- }
- pid->hide_pid = option;
- break;
- default:
- pr_err("proc: unrecognized mount option \"%s\" "
- "or missing value\n", p);
- return 0;
- }
+ struct proc_fs_context *ctx = fc->fs_private;
+ struct fs_parse_result result;
+ int opt;
+
+ opt = fs_parse(fc, &proc_fs_parameters, param, &result);
+ if (opt < 0)
+ return opt;
+
+ switch (opt) {
+ case Opt_gid:
+ ctx->gid = result.uint_32;
+ break;
+
+ case Opt_hidepid:
+ ctx->hidepid = result.uint_32;
+ if (ctx->hidepid < HIDEPID_OFF ||
+ ctx->hidepid > HIDEPID_INVISIBLE)
+ return invalf(fc, "proc: hidepid value must be between 0 and 2.\n");
+ break;
+
+ default:
+ return -EINVAL;
}
- return 1;
+ ctx->mask |= 1 << opt;
+ return 0;
}
-int proc_remount(struct super_block *sb, int *flags, char *data)
+static void proc_apply_options(struct super_block *s,
+ struct fs_context *fc,
+ struct pid_namespace *pid_ns,
+ struct user_namespace *user_ns)
{
+ struct proc_fs_context *ctx = fc->fs_private;
+
+ if (ctx->mask & (1 << Opt_gid))
+ pid_ns->pid_gid = make_kgid(user_ns, ctx->gid);
+ if (ctx->mask & (1 << Opt_hidepid))
+ pid_ns->hide_pid = ctx->hidepid;
+}
+
+static int proc_fill_super(struct super_block *s, struct fs_context *fc)
+{
+ struct pid_namespace *pid_ns = get_pid_ns(s->s_fs_info);
+ struct inode *root_inode;
+ int ret;
+
+ proc_apply_options(s, fc, pid_ns, current_user_ns());
+
+ /* User space would break if executables or devices appear on proc */
+ s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC | SB_I_NODEV;
+ s->s_flags |= SB_NODIRATIME | SB_NOSUID | SB_NOEXEC;
+ s->s_blocksize = 1024;
+ s->s_blocksize_bits = 10;
+ s->s_magic = PROC_SUPER_MAGIC;
+ s->s_op = &proc_sops;
+ s->s_time_gran = 1;
+
+ /*
+ * procfs isn't actually a stacking filesystem; however, there is
+ * too much magic going on inside it to permit stacking things on
+ * top of it
+ */
+ s->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH;
+
+ /* procfs dentries and inodes don't require IO to create */
+ s->s_shrink.seeks = 0;
+
+ pde_get(&proc_root);
+ root_inode = proc_get_inode(s, &proc_root);
+ if (!root_inode) {
+ pr_err("proc_fill_super: get root inode failed\n");
+ return -ENOMEM;
+ }
+
+ s->s_root = d_make_root(root_inode);
+ if (!s->s_root) {
+ pr_err("proc_fill_super: allocate dentry failed\n");
+ return -ENOMEM;
+ }
+
+ ret = proc_setup_self(s);
+ if (ret) {
+ return ret;
+ }
+ return proc_setup_thread_self(s);
+}
+
+static int proc_reconfigure(struct fs_context *fc)
+{
+ struct super_block *sb = fc->root->d_sb;
struct pid_namespace *pid = sb->s_fs_info;
sync_filesystem(sb);
- return !proc_parse_options(data, pid);
+
+ proc_apply_options(sb, fc, pid, current_user_ns());
+ return 0;
}
-static struct dentry *proc_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
+static int proc_get_tree(struct fs_context *fc)
{
- struct pid_namespace *ns;
+ struct proc_fs_context *ctx = fc->fs_private;
- if (flags & SB_KERNMOUNT) {
- ns = data;
- data = NULL;
- } else {
- ns = task_active_pid_ns(current);
- }
+ put_user_ns(fc->user_ns);
+ fc->user_ns = get_user_ns(ctx->pid_ns->user_ns);
+ fc->s_fs_info = ctx->pid_ns;
+ return vfs_get_super(fc, vfs_get_keyed_super, proc_fill_super);
+}
- return mount_ns(fs_type, flags, data, ns, ns->user_ns, proc_fill_super);
+static void proc_fs_context_free(struct fs_context *fc)
+{
+ struct proc_fs_context *ctx = fc->fs_private;
+
+ if (ctx->pid_ns)
+ put_pid_ns(ctx->pid_ns);
+ kfree(ctx);
+}
+
+static const struct fs_context_operations proc_fs_context_ops = {
+ .free = proc_fs_context_free,
+ .parse_param = proc_parse_param,
+ .get_tree = proc_get_tree,
+ .reconfigure = proc_reconfigure,
+};
+
+static int proc_init_fs_context(struct fs_context *fc)
+{
+ struct proc_fs_context *ctx;
+
+ ctx = kzalloc(sizeof(struct proc_fs_context), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->pid_ns = get_pid_ns(task_active_pid_ns(current));
+ fc->fs_private = ctx;
+ fc->ops = &proc_fs_context_ops;
+ return 0;
}
static void proc_kill_sb(struct super_block *sb)
@@ -115,10 +207,11 @@ static void proc_kill_sb(struct super_block *sb)
}
static struct file_system_type proc_fs_type = {
- .name = "proc",
- .mount = proc_mount,
- .kill_sb = proc_kill_sb,
- .fs_flags = FS_USERNS_MOUNT,
+ .name = "proc",
+ .init_fs_context = proc_init_fs_context,
+ .parameters = &proc_fs_parameters,
+ .kill_sb = proc_kill_sb,
+ .fs_flags = FS_USERNS_MOUNT,
};
void __init proc_root_init(void)
@@ -156,7 +249,7 @@ static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentr
{
if (!proc_pid_lookup(dentry, flags))
return NULL;
-
+
return proc_lookup(dir, dentry, flags);
}
@@ -209,9 +302,28 @@ struct proc_dir_entry proc_root = {
int pid_ns_prepare_proc(struct pid_namespace *ns)
{
+ struct proc_fs_context *ctx;
+ struct fs_context *fc;
struct vfsmount *mnt;
- mnt = kern_mount_data(&proc_fs_type, ns);
+ fc = fs_context_for_mount(&proc_fs_type, SB_KERNMOUNT);
+ if (IS_ERR(fc))
+ return PTR_ERR(fc);
+
+ if (fc->user_ns != ns->user_ns) {
+ put_user_ns(fc->user_ns);
+ fc->user_ns = get_user_ns(ns->user_ns);
+ }
+
+ ctx = fc->fs_private;
+ if (ctx->pid_ns != ns) {
+ put_pid_ns(ctx->pid_ns);
+ get_pid_ns(ns);
+ ctx->pid_ns = ns;
+ }
+
+ mnt = fc_mount(fc);
+ put_fs_context(fc);
if (IS_ERR(mnt))
return PTR_ERR(mnt);
diff --git a/fs/super.c b/fs/super.c
index 48e25eba8465..583a0124bc39 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -35,6 +35,7 @@
#include <linux/fsnotify.h>
#include <linux/lockdep.h>
#include <linux/user_namespace.h>
+#include <linux/fs_context.h>
#include <uapi/linux/mount.h>
#include "internal.h"
@@ -476,6 +477,94 @@ void generic_shutdown_super(struct super_block *sb)
EXPORT_SYMBOL(generic_shutdown_super);
/**
+ * sget_fc - Find or create a superblock
+ * @fc: Filesystem context.
+ * @test: Comparison callback
+ * @set: Setup callback
+ *
+ * Find or create a superblock using the parameters stored in the filesystem
+ * context and the two callback functions.
+ *
+ * If an extant superblock is matched, then that will be returned with an
+ * elevated reference count that the caller must transfer or discard.
+ *
+ * If no match is made, a new superblock will be allocated and basic
+ * initialisation will be performed (s_type, s_fs_info and s_id will be set and
+ * the set() callback will be invoked), the superblock will be published and it
+ * will be returned in a partially constructed state with SB_BORN and SB_ACTIVE
+ * as yet unset.
+ */
+struct super_block *sget_fc(struct fs_context *fc,
+ int (*test)(struct super_block *, struct fs_context *),
+ int (*set)(struct super_block *, struct fs_context *))
+{
+ struct super_block *s = NULL;
+ struct super_block *old;
+ struct user_namespace *user_ns = fc->global ? &init_user_ns : fc->user_ns;
+ int err;
+
+ if (!(fc->sb_flags & SB_KERNMOUNT) &&
+ fc->purpose != FS_CONTEXT_FOR_SUBMOUNT) {
+ /* Don't allow mounting unless the caller has CAP_SYS_ADMIN
+ * over the namespace.
+ */
+ if (!(fc->fs_type->fs_flags & FS_USERNS_MOUNT)) {
+ if (!capable(CAP_SYS_ADMIN))
+ return ERR_PTR(-EPERM);
+ } else {
+ if (!ns_capable(fc->user_ns, CAP_SYS_ADMIN))
+ return ERR_PTR(-EPERM);
+ }
+ }
+
+retry:
+ spin_lock(&sb_lock);
+ if (test) {
+ hlist_for_each_entry(old, &fc->fs_type->fs_supers, s_instances) {
+ if (test(old, fc))
+ goto share_extant_sb;
+ }
+ }
+ if (!s) {
+ spin_unlock(&sb_lock);
+ s = alloc_super(fc->fs_type, fc->sb_flags, user_ns);
+ if (!s)
+ return ERR_PTR(-ENOMEM);
+ goto retry;
+ }
+
+ s->s_fs_info = fc->s_fs_info;
+ err = set(s, fc);
+ if (err) {
+ s->s_fs_info = NULL;
+ spin_unlock(&sb_lock);
+ destroy_unused_super(s);
+ return ERR_PTR(err);
+ }
+ fc->s_fs_info = NULL;
+ s->s_type = fc->fs_type;
+ strlcpy(s->s_id, s->s_type->name, sizeof(s->s_id));
+ list_add_tail(&s->s_list, &super_blocks);
+ hlist_add_head(&s->s_instances, &s->s_type->fs_supers);
+ spin_unlock(&sb_lock);
+ get_filesystem(s->s_type);
+ register_shrinker_prepared(&s->s_shrink);
+ return s;
+
+share_extant_sb:
+ if (user_ns != old->s_user_ns) {
+ spin_unlock(&sb_lock);
+ destroy_unused_super(s);
+ return ERR_PTR(-EBUSY);
+ }
+ if (!grab_super(old))
+ goto retry;
+ destroy_unused_super(s);
+ return old;
+}
+EXPORT_SYMBOL(sget_fc);
+
+/**
* sget_userns - find or create a superblock
* @type: filesystem type superblock should belong to
* @test: comparison callback
@@ -835,28 +924,35 @@ rescan:
}
/**
- * do_remount_sb - asks filesystem to change mount options.
- * @sb: superblock in question
- * @sb_flags: revised superblock flags
- * @data: the rest of options
- * @force: whether or not to force the change
+ * reconfigure_super - asks filesystem to change superblock parameters
+ * @fc: The superblock and configuration
*
- * Alters the mount options of a mounted file system.
+ * Alters the configuration parameters of a live superblock.
*/
-int do_remount_sb(struct super_block *sb, int sb_flags, void *data, int force)
+int reconfigure_super(struct fs_context *fc)
{
+ struct super_block *sb = fc->root->d_sb;
int retval;
- int remount_ro;
+ bool remount_ro = false;
+ bool force = fc->sb_flags & SB_FORCE;
+ if (fc->sb_flags_mask & ~MS_RMT_MASK)
+ return -EINVAL;
if (sb->s_writers.frozen != SB_UNFROZEN)
return -EBUSY;
+ retval = security_sb_remount(sb, fc->security);
+ if (retval)
+ return retval;
+
+ if (fc->sb_flags_mask & SB_RDONLY) {
#ifdef CONFIG_BLOCK
- if (!(sb_flags & SB_RDONLY) && bdev_read_only(sb->s_bdev))
- return -EACCES;
+ if (!(fc->sb_flags & SB_RDONLY) && bdev_read_only(sb->s_bdev))
+ return -EACCES;
#endif
- remount_ro = (sb_flags & SB_RDONLY) && !sb_rdonly(sb);
+ remount_ro = (fc->sb_flags & SB_RDONLY) && !sb_rdonly(sb);
+ }
if (remount_ro) {
if (!hlist_empty(&sb->s_pins)) {
@@ -867,13 +963,14 @@ int do_remount_sb(struct super_block *sb, int sb_flags, void *data, int force)
return 0;
if (sb->s_writers.frozen != SB_UNFROZEN)
return -EBUSY;
- remount_ro = (sb_flags & SB_RDONLY) && !sb_rdonly(sb);
+ remount_ro = !sb_rdonly(sb);
}
}
shrink_dcache_sb(sb);
- /* If we are remounting RDONLY and current sb is read/write,
- make sure there are no rw files opened */
+ /* If we are reconfiguring to RDONLY and current sb is read/write,
+ * make sure there are no files open for writing.
+ */
if (remount_ro) {
if (force) {
sb->s_readonly_remount = 1;
@@ -885,8 +982,8 @@ int do_remount_sb(struct super_block *sb, int sb_flags, void *data, int force)
}
}
- if (sb->s_op->remount_fs) {
- retval = sb->s_op->remount_fs(sb, &sb_flags, data);
+ if (fc->ops->reconfigure) {
+ retval = fc->ops->reconfigure(fc);
if (retval) {
if (!force)
goto cancel_readonly;
@@ -895,7 +992,9 @@ int do_remount_sb(struct super_block *sb, int sb_flags, void *data, int force)
sb->s_type->name, retval);
}
}
- sb->s_flags = (sb->s_flags & ~MS_RMT_MASK) | (sb_flags & MS_RMT_MASK);
+
+ WRITE_ONCE(sb->s_flags, ((sb->s_flags & ~fc->sb_flags_mask) |
+ (fc->sb_flags & fc->sb_flags_mask)));
/* Needs to be ordered wrt mnt_is_readonly() */
smp_wmb();
sb->s_readonly_remount = 0;
@@ -922,10 +1021,15 @@ static void do_emergency_remount_callback(struct super_block *sb)
down_write(&sb->s_umount);
if (sb->s_root && sb->s_bdev && (sb->s_flags & SB_BORN) &&
!sb_rdonly(sb)) {
- /*
- * What lock protects sb->s_flags??
- */
- do_remount_sb(sb, SB_RDONLY, NULL, 1);
+ struct fs_context *fc;
+
+ fc = fs_context_for_reconfigure(sb->s_root,
+ SB_RDONLY | SB_FORCE, SB_RDONLY);
+ if (!IS_ERR(fc)) {
+ if (parse_monolithic_mount_data(fc, NULL) == 0)
+ (void)reconfigure_super(fc);
+ put_fs_context(fc);
+ }
}
up_write(&sb->s_umount);
}
@@ -1087,6 +1191,89 @@ struct dentry *mount_ns(struct file_system_type *fs_type,
EXPORT_SYMBOL(mount_ns);
+int set_anon_super_fc(struct super_block *sb, struct fs_context *fc)
+{
+ return set_anon_super(sb, NULL);
+}
+EXPORT_SYMBOL(set_anon_super_fc);
+
+static int test_keyed_super(struct super_block *sb, struct fs_context *fc)
+{
+ return sb->s_fs_info == fc->s_fs_info;
+}
+
+static int test_single_super(struct super_block *s, struct fs_context *fc)
+{
+ return 1;
+}
+
+/**
+ * vfs_get_super - Get a superblock with a search key set in s_fs_info.
+ * @fc: The filesystem context holding the parameters
+ * @keying: How to distinguish superblocks
+ * @fill_super: Helper to initialise a new superblock
+ *
+ * Search for a superblock and create a new one if not found. The search
+ * criterion is controlled by @keying. If the search fails, a new superblock
+ * is created and @fill_super() is called to initialise it.
+ *
+ * @keying can take one of a number of values:
+ *
+ * (1) vfs_get_single_super - Only one superblock of this type may exist on the
+ * system. This is typically used for special system filesystems.
+ *
+ * (2) vfs_get_keyed_super - Multiple superblocks may exist, but they must have
+ * distinct keys (where the key is in s_fs_info). Searching for the same
+ * key again will turn up the superblock for that key.
+ *
+ * (3) vfs_get_independent_super - Multiple superblocks may exist and are
+ * unkeyed. Each call will get a new superblock.
+ *
+ * A permissions check is made by sget_fc() unless we're getting a superblock
+ * for a kernel-internal mount or a submount.
+ */
+int vfs_get_super(struct fs_context *fc,
+ enum vfs_get_super_keying keying,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc))
+{
+ int (*test)(struct super_block *, struct fs_context *);
+ struct super_block *sb;
+
+ switch (keying) {
+ case vfs_get_single_super:
+ test = test_single_super;
+ break;
+ case vfs_get_keyed_super:
+ test = test_keyed_super;
+ break;
+ case vfs_get_independent_super:
+ test = NULL;
+ break;
+ default:
+ BUG();
+ }
+
+ sb = sget_fc(fc, test, set_anon_super_fc);
+ if (IS_ERR(sb))
+ return PTR_ERR(sb);
+
+ if (!sb->s_root) {
+ int err = fill_super(sb, fc);
+ if (err) {
+ deactivate_locked_super(sb);
+ return err;
+ }
+
+ sb->s_flags |= SB_ACTIVE;
+ }
+
+ BUG_ON(fc->root);
+ fc->root = dget(sb->s_root);
+ return 0;
+}
+EXPORT_SYMBOL(vfs_get_super);
+
#ifdef CONFIG_BLOCK
static int set_bdev_super(struct super_block *s, void *data)
{
@@ -1212,6 +1399,31 @@ struct dentry *mount_nodev(struct file_system_type *fs_type,
}
EXPORT_SYMBOL(mount_nodev);
+static int reconfigure_single(struct super_block *s,
+ int flags, void *data)
+{
+ struct fs_context *fc;
+ int ret;
+
+ /* The caller really need to be passing fc down into mount_single(),
+ * then a chunk of this can be removed. [Bollocks -- AV]
+ * Better yet, reconfiguration shouldn't happen, but rather the second
+ * mount should be rejected if the parameters are not compatible.
+ */
+ fc = fs_context_for_reconfigure(s->s_root, flags, MS_RMT_MASK);
+ if (IS_ERR(fc))
+ return PTR_ERR(fc);
+
+ ret = parse_monolithic_mount_data(fc, data);
+ if (ret < 0)
+ goto out;
+
+ ret = reconfigure_super(fc);
+out:
+ put_fs_context(fc);
+ return ret;
+}
+
static int compare_single(struct super_block *s, void *p)
{
return 1;
@@ -1229,41 +1441,64 @@ struct dentry *mount_single(struct file_system_type *fs_type,
return ERR_CAST(s);
if (!s->s_root) {
error = fill_super(s, data, flags & SB_SILENT ? 1 : 0);
- if (error) {
- deactivate_locked_super(s);
- return ERR_PTR(error);
- }
- s->s_flags |= SB_ACTIVE;
+ if (!error)
+ s->s_flags |= SB_ACTIVE;
} else {
- do_remount_sb(s, flags, data, 0);
+ error = reconfigure_single(s, flags, data);
+ }
+ if (unlikely(error)) {
+ deactivate_locked_super(s);
+ return ERR_PTR(error);
}
return dget(s->s_root);
}
EXPORT_SYMBOL(mount_single);
-struct dentry *
-mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
+/**
+ * vfs_get_tree - Get the mountable root
+ * @fc: The superblock configuration context.
+ *
+ * The filesystem is invoked to get or create a superblock which can then later
+ * be used for mounting. The filesystem places a pointer to the root to be
+ * used for mounting in @fc->root.
+ */
+int vfs_get_tree(struct fs_context *fc)
{
- struct dentry *root;
struct super_block *sb;
- int error = -ENOMEM;
- void *sec_opts = NULL;
+ int error;
- if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) {
- error = security_sb_eat_lsm_opts(data, &sec_opts);
- if (error)
- return ERR_PTR(error);
+ if (fc->fs_type->fs_flags & FS_REQUIRES_DEV && !fc->source) {
+ errorf(fc, "Filesystem requires source device");
+ return -ENOENT;
}
- root = type->mount(type, flags, name, data);
- if (IS_ERR(root)) {
- error = PTR_ERR(root);
- goto out_free_secdata;
+ if (fc->root)
+ return -EBUSY;
+
+ /* Get the mountable root in fc->root, with a ref on the root and a ref
+ * on the superblock.
+ */
+ error = fc->ops->get_tree(fc);
+ if (error < 0)
+ return error;
+
+ if (!fc->root) {
+ pr_err("Filesystem %s get_tree() didn't set fc->root\n",
+ fc->fs_type->name);
+ /* We don't know what the locking state of the superblock is -
+ * if there is a superblock.
+ */
+ BUG();
}
- sb = root->d_sb;
- BUG_ON(!sb);
+
+ sb = fc->root->d_sb;
WARN_ON(!sb->s_bdi);
+ if (fc->subtype && !sb->s_subtype) {
+ sb->s_subtype = fc->subtype;
+ fc->subtype = NULL;
+ }
+
/*
* Write barrier is for super_cache_count(). We place it before setting
* SB_BORN as the data dependency between the two functions is the
@@ -1273,14 +1508,10 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
smp_wmb();
sb->s_flags |= SB_BORN;
- error = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
- if (error)
- goto out_sb;
-
- if (!(flags & (MS_KERNMOUNT|MS_SUBMOUNT))) {
- error = security_sb_kern_mount(sb);
- if (error)
- goto out_sb;
+ error = security_sb_set_mnt_opts(sb, fc->security, 0, NULL);
+ if (unlikely(error)) {
+ fc_drop_locked(fc);
+ return error;
}
/*
@@ -1290,18 +1521,11 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
* violate this rule.
*/
WARN((sb->s_maxbytes < 0), "%s set sb->s_maxbytes to "
- "negative value (%lld)\n", type->name, sb->s_maxbytes);
+ "negative value (%lld)\n", fc->fs_type->name, sb->s_maxbytes);
- up_write(&sb->s_umount);
- security_free_mnt_opts(&sec_opts);
- return root;
-out_sb:
- dput(root);
- deactivate_locked_super(sb);
-out_free_secdata:
- security_free_mnt_opts(&sec_opts);
- return ERR_PTR(error);
+ return 0;
}
+EXPORT_SYMBOL(vfs_get_tree);
/*
* Setup private BDI for given superblock. It gets automatically cleaned up
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 92682fcc41f6..4cb21b558a85 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -13,34 +13,69 @@
#include <linux/magic.h>
#include <linux/mount.h>
#include <linux/init.h>
+#include <linux/slab.h>
#include <linux/user_namespace.h>
+#include <linux/fs_context.h>
+#include <net/net_namespace.h>
#include "sysfs.h"
static struct kernfs_root *sysfs_root;
struct kernfs_node *sysfs_root_kn;
-static struct dentry *sysfs_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
+static int sysfs_get_tree(struct fs_context *fc)
{
- struct dentry *root;
- void *ns;
- bool new_sb = false;
+ struct kernfs_fs_context *kfc = fc->fs_private;
+ int ret;
- if (!(flags & SB_KERNMOUNT)) {
+ ret = kernfs_get_tree(fc);
+ if (ret)
+ return ret;
+
+ if (kfc->new_sb_created)
+ fc->root->d_sb->s_iflags |= SB_I_USERNS_VISIBLE;
+ return 0;
+}
+
+static void sysfs_fs_context_free(struct fs_context *fc)
+{
+ struct kernfs_fs_context *kfc = fc->fs_private;
+
+ if (kfc->ns_tag)
+ kobj_ns_drop(KOBJ_NS_TYPE_NET, kfc->ns_tag);
+ kernfs_free_fs_context(fc);
+ kfree(kfc);
+}
+
+static const struct fs_context_operations sysfs_fs_context_ops = {
+ .free = sysfs_fs_context_free,
+ .get_tree = sysfs_get_tree,
+};
+
+static int sysfs_init_fs_context(struct fs_context *fc)
+{
+ struct kernfs_fs_context *kfc;
+ struct net *netns;
+
+ if (!(fc->sb_flags & SB_KERNMOUNT)) {
if (!kobj_ns_current_may_mount(KOBJ_NS_TYPE_NET))
- return ERR_PTR(-EPERM);
+ return -EPERM;
}
- ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
- root = kernfs_mount_ns(fs_type, flags, sysfs_root,
- SYSFS_MAGIC, &new_sb, ns);
- if (!new_sb)
- kobj_ns_drop(KOBJ_NS_TYPE_NET, ns);
- else if (!IS_ERR(root))
- root->d_sb->s_iflags |= SB_I_USERNS_VISIBLE;
+ kfc = kzalloc(sizeof(struct kernfs_fs_context), GFP_KERNEL);
+ if (!kfc)
+ return -ENOMEM;
- return root;
+ kfc->ns_tag = netns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
+ kfc->root = sysfs_root;
+ kfc->magic = SYSFS_MAGIC;
+ fc->fs_private = kfc;
+ fc->ops = &sysfs_fs_context_ops;
+ if (fc->user_ns)
+ put_user_ns(fc->user_ns);
+ fc->user_ns = get_user_ns(netns->user_ns);
+ fc->global = true;
+ return 0;
}
static void sysfs_kill_sb(struct super_block *sb)
@@ -52,10 +87,10 @@ static void sysfs_kill_sb(struct super_block *sb)
}
static struct file_system_type sysfs_fs_type = {
- .name = "sysfs",
- .mount = sysfs_mount,
- .kill_sb = sysfs_kill_sb,
- .fs_flags = FS_USERNS_MOUNT,
+ .name = "sysfs",
+ .init_fs_context = sysfs_init_fs_context,
+ .kill_sb = sysfs_kill_sb,
+ .fs_flags = FS_USERNS_MOUNT,
};
int __init sysfs_init(void)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.