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-rw-r--r--mm/shmem.c140
1 files changed, 97 insertions, 43 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index eef4ebea5158..7e5030ae18ff 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -433,8 +433,6 @@ static swp_entry_t *shmem_swp_alloc(struct shmem_inode_info *info, unsigned long
spin_unlock(&info->lock);
page = shmem_dir_alloc(mapping_gfp_mask(inode->i_mapping));
- if (page)
- set_page_private(page, 0);
spin_lock(&info->lock);
if (!page) {
@@ -729,10 +727,11 @@ done2:
if (inode->i_mapping->nrpages && (info->flags & SHMEM_PAGEIN)) {
/*
* Call truncate_inode_pages again: racing shmem_unuse_inode
- * may have swizzled a page in from swap since vmtruncate or
- * generic_delete_inode did it, before we lowered next_index.
- * Also, though shmem_getpage checks i_size before adding to
- * cache, no recheck after: so fix the narrow window there too.
+ * may have swizzled a page in from swap since
+ * truncate_pagecache or generic_delete_inode did it, before we
+ * lowered next_index. Also, though shmem_getpage checks
+ * i_size before adding to cache, no recheck after: so fix the
+ * narrow window there too.
*
* Recalling truncate_inode_pages_range and unmap_mapping_range
* every time for punch_hole (which never got a chance to clear
@@ -762,19 +761,16 @@ done2:
}
}
-static void shmem_truncate(struct inode *inode)
-{
- shmem_truncate_range(inode, inode->i_size, (loff_t)-1);
-}
-
static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = dentry->d_inode;
- struct page *page = NULL;
int error;
if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
- if (attr->ia_size < inode->i_size) {
+ loff_t newsize = attr->ia_size;
+ struct page *page = NULL;
+
+ if (newsize < inode->i_size) {
/*
* If truncating down to a partial page, then
* if that page is already allocated, hold it
@@ -782,9 +778,9 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
* truncate_partial_page cannnot miss it were
* it assigned to swap.
*/
- if (attr->ia_size & (PAGE_CACHE_SIZE-1)) {
+ if (newsize & (PAGE_CACHE_SIZE-1)) {
(void) shmem_getpage(inode,
- attr->ia_size>>PAGE_CACHE_SHIFT,
+ newsize >> PAGE_CACHE_SHIFT,
&page, SGP_READ, NULL);
if (page)
unlock_page(page);
@@ -796,24 +792,29 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
* if it's being fully truncated to zero-length: the
* nrpages check is efficient enough in that case.
*/
- if (attr->ia_size) {
+ if (newsize) {
struct shmem_inode_info *info = SHMEM_I(inode);
spin_lock(&info->lock);
info->flags &= ~SHMEM_PAGEIN;
spin_unlock(&info->lock);
}
}
+
+ error = simple_setsize(inode, newsize);
+ if (page)
+ page_cache_release(page);
+ if (error)
+ return error;
+ shmem_truncate_range(inode, newsize, (loff_t)-1);
}
error = inode_change_ok(inode, attr);
if (!error)
- error = inode_setattr(inode, attr);
+ generic_setattr(inode, attr);
#ifdef CONFIG_TMPFS_POSIX_ACL
if (!error && (attr->ia_valid & ATTR_MODE))
error = generic_acl_chmod(inode);
#endif
- if (page)
- page_cache_release(page);
return error;
}
@@ -821,11 +822,11 @@ static void shmem_delete_inode(struct inode *inode)
{
struct shmem_inode_info *info = SHMEM_I(inode);
- if (inode->i_op->truncate == shmem_truncate) {
+ if (inode->i_mapping->a_ops == &shmem_aops) {
truncate_inode_pages(inode->i_mapping, 0);
shmem_unacct_size(info->flags, inode->i_size);
inode->i_size = 0;
- shmem_truncate(inode);
+ shmem_truncate_range(inode, 0, (loff_t)-1);
if (!list_empty(&info->swaplist)) {
mutex_lock(&shmem_swaplist_mutex);
list_del_init(&info->swaplist);
@@ -1545,8 +1546,8 @@ static int shmem_mmap(struct file *file, struct vm_area_struct *vma)
return 0;
}
-static struct inode *shmem_get_inode(struct super_block *sb, int mode,
- dev_t dev, unsigned long flags)
+static struct inode *shmem_get_inode(struct super_block *sb, const struct inode *dir,
+ int mode, dev_t dev, unsigned long flags)
{
struct inode *inode;
struct shmem_inode_info *info;
@@ -1557,9 +1558,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, int mode,
inode = new_inode(sb);
if (inode) {
- inode->i_mode = mode;
- inode->i_uid = current_fsuid();
- inode->i_gid = current_fsgid();
+ inode_init_owner(inode, dir, mode);
inode->i_blocks = 0;
inode->i_mapping->backing_dev_info = &shmem_backing_dev_info;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
@@ -1814,7 +1813,7 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
struct inode *inode;
int error = -ENOSPC;
- inode = shmem_get_inode(dir->i_sb, mode, dev, VM_NORESERVE);
+ inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE);
if (inode) {
error = security_inode_init_security(inode, dir, NULL, NULL,
NULL);
@@ -1833,11 +1832,6 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
#else
error = 0;
#endif
- if (dir->i_mode & S_ISGID) {
- inode->i_gid = dir->i_gid;
- if (S_ISDIR(mode))
- inode->i_mode |= S_ISGID;
- }
dir->i_size += BOGO_DIRENT_SIZE;
dir->i_ctime = dir->i_mtime = CURRENT_TIME;
d_instantiate(dentry, inode);
@@ -1957,7 +1951,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
if (len > PAGE_CACHE_SIZE)
return -ENAMETOOLONG;
- inode = shmem_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE);
+ inode = shmem_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE);
if (!inode)
return -ENOSPC;
@@ -1992,8 +1986,6 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
unlock_page(page);
page_cache_release(page);
}
- if (dir->i_mode & S_ISGID)
- inode->i_gid = dir->i_gid;
dir->i_size += BOGO_DIRENT_SIZE;
dir->i_ctime = dir->i_mtime = CURRENT_TIME;
d_instantiate(dentry, inode);
@@ -2033,7 +2025,6 @@ static const struct inode_operations shmem_symlink_inline_operations = {
};
static const struct inode_operations shmem_symlink_inode_operations = {
- .truncate = shmem_truncate,
.readlink = generic_readlink,
.follow_link = shmem_follow_link,
.put_link = shmem_put_link,
@@ -2071,14 +2062,14 @@ static int shmem_xattr_security_set(struct dentry *dentry, const char *name,
size, flags);
}
-static struct xattr_handler shmem_xattr_security_handler = {
+static const struct xattr_handler shmem_xattr_security_handler = {
.prefix = XATTR_SECURITY_PREFIX,
.list = shmem_xattr_security_list,
.get = shmem_xattr_security_get,
.set = shmem_xattr_security_set,
};
-static struct xattr_handler *shmem_xattr_handlers[] = {
+static const struct xattr_handler *shmem_xattr_handlers[] = {
&generic_acl_access_handler,
&generic_acl_default_handler,
&shmem_xattr_security_handler,
@@ -2366,7 +2357,7 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent)
sb->s_flags |= MS_POSIXACL;
#endif
- inode = shmem_get_inode(sb, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE);
+ inode = shmem_get_inode(sb, NULL, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE);
if (!inode)
goto failed;
inode->i_uid = sbinfo->uid;
@@ -2444,14 +2435,13 @@ static const struct file_operations shmem_file_operations = {
.write = do_sync_write,
.aio_read = shmem_file_aio_read,
.aio_write = generic_file_aio_write,
- .fsync = simple_sync_file,
+ .fsync = noop_fsync,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
#endif
};
static const struct inode_operations shmem_inode_operations = {
- .truncate = shmem_truncate,
.setattr = shmem_notify_change,
.truncate_range = shmem_truncate_range,
#ifdef CONFIG_TMPFS_POSIX_ACL
@@ -2570,6 +2560,45 @@ out4:
return error;
}
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+/**
+ * mem_cgroup_get_shmem_target - find a page or entry assigned to the shmem file
+ * @inode: the inode to be searched
+ * @pgoff: the offset to be searched
+ * @pagep: the pointer for the found page to be stored
+ * @ent: the pointer for the found swap entry to be stored
+ *
+ * If a page is found, refcount of it is incremented. Callers should handle
+ * these refcount.
+ */
+void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t pgoff,
+ struct page **pagep, swp_entry_t *ent)
+{
+ swp_entry_t entry = { .val = 0 }, *ptr;
+ struct page *page = NULL;
+ struct shmem_inode_info *info = SHMEM_I(inode);
+
+ if ((pgoff << PAGE_CACHE_SHIFT) >= i_size_read(inode))
+ goto out;
+
+ spin_lock(&info->lock);
+ ptr = shmem_swp_entry(info, pgoff, NULL);
+#ifdef CONFIG_SWAP
+ if (ptr && ptr->val) {
+ entry.val = ptr->val;
+ page = find_get_page(&swapper_space, entry.val);
+ } else
+#endif
+ page = find_get_page(inode->i_mapping, pgoff);
+ if (ptr)
+ shmem_swp_unmap(ptr);
+ spin_unlock(&info->lock);
+out:
+ *pagep = page;
+ *ent = entry;
+}
+#endif
+
#else /* !CONFIG_SHMEM */
/*
@@ -2609,9 +2638,34 @@ int shmem_lock(struct file *file, int lock, struct user_struct *user)
return 0;
}
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+/**
+ * mem_cgroup_get_shmem_target - find a page or entry assigned to the shmem file
+ * @inode: the inode to be searched
+ * @pgoff: the offset to be searched
+ * @pagep: the pointer for the found page to be stored
+ * @ent: the pointer for the found swap entry to be stored
+ *
+ * If a page is found, refcount of it is incremented. Callers should handle
+ * these refcount.
+ */
+void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t pgoff,
+ struct page **pagep, swp_entry_t *ent)
+{
+ struct page *page = NULL;
+
+ if ((pgoff << PAGE_CACHE_SHIFT) >= i_size_read(inode))
+ goto out;
+ page = find_get_page(inode->i_mapping, pgoff);
+out:
+ *pagep = page;
+ *ent = (swp_entry_t){ .val = 0 };
+}
+#endif
+
#define shmem_vm_ops generic_file_vm_ops
#define shmem_file_operations ramfs_file_operations
-#define shmem_get_inode(sb, mode, dev, flags) ramfs_get_inode(sb, mode, dev)
+#define shmem_get_inode(sb, dir, mode, dev, flags) ramfs_get_inode(sb, dir, mode, dev)
#define shmem_acct_size(flags, size) 0
#define shmem_unacct_size(flags, size) do {} while (0)
#define SHMEM_MAX_BYTES MAX_LFS_FILESIZE
@@ -2655,7 +2709,7 @@ struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags
path.mnt = mntget(shm_mnt);
error = -ENOSPC;
- inode = shmem_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0, flags);
+ inode = shmem_get_inode(root->d_sb, NULL, S_IFREG | S_IRWXUGO, 0, flags);
if (!inode)
goto put_dentry;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.