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-rw-r--r--mm/shmem.c78
1 files changed, 38 insertions, 40 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index cf2d0ca010bc..dbe0c1e8349c 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -31,7 +31,7 @@
#include <linux/mm.h>
#include <linux/export.h>
#include <linux/swap.h>
-#include <linux/aio.h>
+#include <linux/uio.h>
static struct vfsmount *shm_mnt;
@@ -544,7 +544,7 @@ EXPORT_SYMBOL_GPL(shmem_truncate_range);
static int shmem_setattr(struct dentry *dentry, struct iattr *attr)
{
- struct inode *inode = dentry->d_inode;
+ struct inode *inode = d_inode(dentry);
struct shmem_inode_info *info = SHMEM_I(inode);
int error;
@@ -569,7 +569,7 @@ static int shmem_setattr(struct dentry *dentry, struct iattr *attr)
i_size_write(inode, newsize);
inode->i_ctime = inode->i_mtime = CURRENT_TIME;
}
- if (newsize < oldsize) {
+ if (newsize <= oldsize) {
loff_t holebegin = round_up(newsize, PAGE_SIZE);
unmap_mapping_range(inode->i_mapping, holebegin, 0, 1);
shmem_truncate_range(inode, newsize, (loff_t)-1);
@@ -2274,7 +2274,7 @@ static int shmem_create(struct inode *dir, struct dentry *dentry, umode_t mode,
*/
static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
{
- struct inode *inode = old_dentry->d_inode;
+ struct inode *inode = d_inode(old_dentry);
int ret;
/*
@@ -2298,7 +2298,7 @@ out:
static int shmem_unlink(struct inode *dir, struct dentry *dentry)
{
- struct inode *inode = dentry->d_inode;
+ struct inode *inode = d_inode(dentry);
if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode))
shmem_free_inode(inode->i_sb);
@@ -2315,7 +2315,7 @@ static int shmem_rmdir(struct inode *dir, struct dentry *dentry)
if (!simple_empty(dentry))
return -ENOTEMPTY;
- drop_nlink(dentry->d_inode);
+ drop_nlink(d_inode(dentry));
drop_nlink(dir);
return shmem_unlink(dir, dentry);
}
@@ -2336,8 +2336,8 @@ static int shmem_exchange(struct inode *old_dir, struct dentry *old_dentry, stru
}
old_dir->i_ctime = old_dir->i_mtime =
new_dir->i_ctime = new_dir->i_mtime =
- old_dentry->d_inode->i_ctime =
- new_dentry->d_inode->i_ctime = CURRENT_TIME;
+ d_inode(old_dentry)->i_ctime =
+ d_inode(new_dentry)->i_ctime = CURRENT_TIME;
return 0;
}
@@ -2376,7 +2376,7 @@ static int shmem_whiteout(struct inode *old_dir, struct dentry *old_dentry)
*/
static int shmem_rename2(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags)
{
- struct inode *inode = old_dentry->d_inode;
+ struct inode *inode = d_inode(old_dentry);
int they_are_dirs = S_ISDIR(inode->i_mode);
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
@@ -2396,10 +2396,10 @@ static int shmem_rename2(struct inode *old_dir, struct dentry *old_dentry, struc
return error;
}
- if (new_dentry->d_inode) {
+ if (d_really_is_positive(new_dentry)) {
(void) shmem_unlink(new_dir, new_dentry);
if (they_are_dirs) {
- drop_nlink(new_dentry->d_inode);
+ drop_nlink(d_inode(new_dentry));
drop_nlink(old_dir);
}
} else if (they_are_dirs) {
@@ -2451,6 +2451,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
return -ENOMEM;
}
inode->i_op = &shmem_short_symlink_operations;
+ inode->i_link = info->symlink;
} else {
error = shmem_getpage(inode, 0, &page, SGP_WRITE, NULL);
if (error) {
@@ -2474,30 +2475,23 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
return 0;
}
-static void *shmem_follow_short_symlink(struct dentry *dentry, struct nameidata *nd)
-{
- nd_set_link(nd, SHMEM_I(dentry->d_inode)->symlink);
- return NULL;
-}
-
-static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *shmem_follow_link(struct dentry *dentry, void **cookie)
{
struct page *page = NULL;
- int error = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ, NULL);
- nd_set_link(nd, error ? ERR_PTR(error) : kmap(page));
- if (page)
- unlock_page(page);
- return page;
+ int error = shmem_getpage(d_inode(dentry), 0, &page, SGP_READ, NULL);
+ if (error)
+ return ERR_PTR(error);
+ unlock_page(page);
+ *cookie = page;
+ return kmap(page);
}
-static void shmem_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
+static void shmem_put_link(struct inode *unused, void *cookie)
{
- if (!IS_ERR(nd_get_link(nd))) {
- struct page *page = cookie;
- kunmap(page);
- mark_page_accessed(page);
- page_cache_release(page);
- }
+ struct page *page = cookie;
+ kunmap(page);
+ mark_page_accessed(page);
+ page_cache_release(page);
}
#ifdef CONFIG_TMPFS_XATTR
@@ -2574,7 +2568,7 @@ static int shmem_xattr_validate(const char *name)
static ssize_t shmem_getxattr(struct dentry *dentry, const char *name,
void *buffer, size_t size)
{
- struct shmem_inode_info *info = SHMEM_I(dentry->d_inode);
+ struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
int err;
/*
@@ -2595,7 +2589,7 @@ static ssize_t shmem_getxattr(struct dentry *dentry, const char *name,
static int shmem_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
- struct shmem_inode_info *info = SHMEM_I(dentry->d_inode);
+ struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
int err;
/*
@@ -2615,7 +2609,7 @@ static int shmem_setxattr(struct dentry *dentry, const char *name,
static int shmem_removexattr(struct dentry *dentry, const char *name)
{
- struct shmem_inode_info *info = SHMEM_I(dentry->d_inode);
+ struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
int err;
/*
@@ -2635,14 +2629,14 @@ static int shmem_removexattr(struct dentry *dentry, const char *name)
static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
- struct shmem_inode_info *info = SHMEM_I(dentry->d_inode);
+ struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
return simple_xattr_list(&info->xattrs, buffer, size);
}
#endif /* CONFIG_TMPFS_XATTR */
static const struct inode_operations shmem_short_symlink_operations = {
.readlink = generic_readlink,
- .follow_link = shmem_follow_short_symlink,
+ .follow_link = simple_follow_link,
#ifdef CONFIG_TMPFS_XATTR
.setxattr = shmem_setxattr,
.getxattr = shmem_getxattr,
@@ -3118,8 +3112,6 @@ static const struct file_operations shmem_file_operations = {
.mmap = shmem_mmap,
#ifdef CONFIG_TMPFS
.llseek = shmem_file_llseek,
- .read = new_sync_read,
- .write = new_sync_write,
.read_iter = shmem_file_read_iter,
.write_iter = generic_file_write_iter,
.fsync = noop_fsync,
@@ -3371,8 +3363,8 @@ put_path:
* shmem_kernel_file_setup - get an unlinked file living in tmpfs which must be
* kernel internal. There will be NO LSM permission checks against the
* underlying inode. So users of this interface must do LSM checks at a
- * higher layer. The one user is the big_key implementation. LSM checks
- * are provided at the key level rather than the inode level.
+ * higher layer. The users are the big_key and shm implementations. LSM
+ * checks are provided at the key or shm level rather than the inode.
* @name: name for dentry (to be seen in /proc/<pid>/maps
* @size: size to be set for the file
* @flags: VM_NORESERVE suppresses pre-accounting of the entire object size
@@ -3403,7 +3395,13 @@ int shmem_zero_setup(struct vm_area_struct *vma)
struct file *file;
loff_t size = vma->vm_end - vma->vm_start;
- file = shmem_file_setup("dev/zero", size, vma->vm_flags);
+ /*
+ * Cloning a new file under mmap_sem leads to a lock ordering conflict
+ * between XFS directory reading and selinux: since this file is only
+ * accessible to the user through its mapping, use S_PRIVATE flag to
+ * bypass file security, in the same way as shmem_kernel_file_setup().
+ */
+ file = __shmem_file_setup("dev/zero", size, vma->vm_flags, S_PRIVATE);
if (IS_ERR(file))
return PTR_ERR(file);
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-04 00:38:24 +0000