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-rw-r--r--mm/shmem.c42
1 files changed, 21 insertions, 21 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index de981370fbc5..4caf8ed24d65 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -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);
@@ -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(d_inode(dentry))->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(d_inode(dentry), 0, &page, SGP_READ, NULL);
- nd_set_link(nd, error ? ERR_PTR(error) : kmap(page));
- if (page)
- unlock_page(page);
- return page;
+ 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
@@ -2642,7 +2636,7 @@ static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
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,
@@ -3401,7 +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);