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path: root/fs/cifs/cifs_dfs_ref.c
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Diffstat (limited to 'fs/cifs/cifs_dfs_ref.c')
-rw-r--r--fs/cifs/cifs_dfs_ref.c138
1 files changed, 86 insertions, 52 deletions
diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index b97c74efd04a..d9b99abe1243 100644
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -25,6 +25,7 @@
#include "dns_resolve.h"
#include "cifs_debug.h"
#include "cifs_unicode.h"
+#include "dfs_cache.h"
static LIST_HEAD(cifs_dfs_automount_list);
@@ -126,7 +127,7 @@ cifs_build_devname(char *nodename, const char *prepath)
* @sb_mountdata: parent/root DFS mount options (template)
* @fullpath: full path in UNC format
* @ref: server's referral
- * @devname: pointer for saving device name
+ * @devname: optional pointer for saving device name
*
* creates mount options for submount based on template options sb_mountdata
* and replacing unc,ip,prefixpath options with ones we've got form ref_unc.
@@ -140,6 +141,7 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
char **devname)
{
int rc;
+ char *name;
char *mountdata = NULL;
const char *prepath = NULL;
int md_len;
@@ -158,17 +160,17 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
prepath++;
}
- *devname = cifs_build_devname(ref->node_name, prepath);
- if (IS_ERR(*devname)) {
- rc = PTR_ERR(*devname);
- *devname = NULL;
+ name = cifs_build_devname(ref->node_name, prepath);
+ if (IS_ERR(name)) {
+ rc = PTR_ERR(name);
+ name = NULL;
goto compose_mount_options_err;
}
- rc = dns_resolve_server_name_to_ip(*devname, &srvIP);
+ rc = dns_resolve_server_name_to_ip(name, &srvIP);
if (rc < 0) {
cifs_dbg(FYI, "%s: Failed to resolve server part of %s to IP: %d\n",
- __func__, *devname, rc);
+ __func__, name, rc);
goto compose_mount_options_err;
}
@@ -224,6 +226,9 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
strcat(mountdata, "ip=");
strcat(mountdata, srvIP);
+ if (devname)
+ *devname = name;
+
/*cifs_dbg(FYI, "%s: parent mountdata: %s\n", __func__, sb_mountdata);*/
/*cifs_dbg(FYI, "%s: submount mountdata: %s\n", __func__, mountdata );*/
@@ -234,8 +239,7 @@ compose_mount_options_out:
compose_mount_options_err:
kfree(mountdata);
mountdata = ERR_PTR(rc);
- kfree(*devname);
- *devname = NULL;
+ kfree(name);
goto compose_mount_options_out;
}
@@ -251,20 +255,30 @@ static struct vfsmount *cifs_dfs_do_refmount(struct dentry *mntpt,
{
struct vfsmount *mnt;
char *mountdata;
- char *devname = NULL;
+ char *devname;
+
+ /*
+ * Always pass down the DFS full path to smb3_do_mount() so we
+ * can use it later for failover.
+ */
+ devname = kstrndup(fullpath, strlen(fullpath), GFP_KERNEL);
+ if (!devname)
+ return ERR_PTR(-ENOMEM);
+
+ convert_delimiter(devname, '/');
/* strip first '\' from fullpath */
mountdata = cifs_compose_mount_options(cifs_sb->mountdata,
- fullpath + 1, ref, &devname);
-
- if (IS_ERR(mountdata))
+ fullpath + 1, ref, NULL);
+ if (IS_ERR(mountdata)) {
+ kfree(devname);
return (struct vfsmount *)mountdata;
+ }
mnt = vfs_submount(mntpt, &cifs_fs_type, devname, mountdata);
kfree(mountdata);
kfree(devname);
return mnt;
-
}
static void dump_referral(const struct dfs_info3_param *ref)
@@ -282,16 +296,15 @@ static void dump_referral(const struct dfs_info3_param *ref)
*/
static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
{
- struct dfs_info3_param *referrals = NULL;
- unsigned int num_referrals = 0;
+ struct dfs_info3_param referral = {0};
struct cifs_sb_info *cifs_sb;
struct cifs_ses *ses;
- char *full_path;
+ struct cifs_tcon *tcon;
+ char *full_path, *root_path;
unsigned int xid;
- int i;
+ int len;
int rc;
struct vfsmount *mnt;
- struct tcon_link *tlink;
cifs_dbg(FYI, "in %s\n", __func__);
BUG_ON(IS_ROOT(mntpt));
@@ -315,48 +328,69 @@ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
if (full_path == NULL)
goto cdda_exit;
- tlink = cifs_sb_tlink(cifs_sb);
- if (IS_ERR(tlink)) {
- mnt = ERR_CAST(tlink);
+ cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
+
+ if (!cifs_sb_master_tlink(cifs_sb)) {
+ cifs_dbg(FYI, "%s: master tlink is NULL\n", __func__);
goto free_full_path;
}
- ses = tlink_tcon(tlink)->ses;
+ tcon = cifs_sb_master_tcon(cifs_sb);
+ if (!tcon) {
+ cifs_dbg(FYI, "%s: master tcon is NULL\n", __func__);
+ goto free_full_path;
+ }
+
+ root_path = kstrdup(tcon->treeName, GFP_KERNEL);
+ if (!root_path) {
+ mnt = ERR_PTR(-ENOMEM);
+ goto free_full_path;
+ }
+ cifs_dbg(FYI, "%s: root path: %s\n", __func__, root_path);
+
+ ses = tcon->ses;
xid = get_xid();
- rc = get_dfs_path(xid, ses, full_path + 1, cifs_sb->local_nls,
- &num_referrals, &referrals,
- cifs_remap(cifs_sb));
- free_xid(xid);
- cifs_put_tlink(tlink);
-
- mnt = ERR_PTR(-ENOENT);
- for (i = 0; i < num_referrals; i++) {
- int len;
- dump_referral(referrals + i);
- /* connect to a node */
- len = strlen(referrals[i].node_name);
- if (len < 2) {
- cifs_dbg(VFS, "%s: Net Address path too short: %s\n",
- __func__, referrals[i].node_name);
- mnt = ERR_PTR(-EINVAL);
- break;
- }
- mnt = cifs_dfs_do_refmount(mntpt, cifs_sb,
- full_path, referrals + i);
- cifs_dbg(FYI, "%s: cifs_dfs_do_refmount:%s , mnt:%p\n",
- __func__, referrals[i].node_name, mnt);
- if (!IS_ERR(mnt))
- goto success;
+ /*
+ * If DFS root has been expired, then unconditionally fetch it again to
+ * refresh DFS referral cache.
+ */
+ rc = dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
+ root_path + 1, NULL, NULL);
+ if (!rc) {
+ rc = dfs_cache_find(xid, ses, cifs_sb->local_nls,
+ cifs_remap(cifs_sb), full_path + 1,
+ &referral, NULL);
}
- /* no valid submounts were found; return error from get_dfs_path() by
- * preference */
- if (rc != 0)
+ free_xid(xid);
+
+ if (rc) {
mnt = ERR_PTR(rc);
+ goto free_root_path;
+ }
+
+ dump_referral(&referral);
-success:
- free_dfs_info_array(referrals, num_referrals);
+ len = strlen(referral.node_name);
+ if (len < 2) {
+ cifs_dbg(VFS, "%s: Net Address path too short: %s\n",
+ __func__, referral.node_name);
+ mnt = ERR_PTR(-EINVAL);
+ goto free_dfs_ref;
+ }
+ /*
+ * cifs_mount() will retry every available node server in case
+ * of failures.
+ */
+ mnt = cifs_dfs_do_refmount(mntpt, cifs_sb, full_path, &referral);
+ cifs_dbg(FYI, "%s: cifs_dfs_do_refmount:%s , mnt:%p\n", __func__,
+ referral.node_name, mnt);
+
+free_dfs_ref:
+ free_dfs_info_param(&referral);
+free_root_path:
+ kfree(root_path);
free_full_path:
kfree(full_path);
cdda_exit:
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.