a7y18lte-ubports/android_kernel_samsung_universal7885
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[PATCH] ext3: ext3_symlink should use GFP_NOFS allocations inside

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This patch fixes illegal __GFP_FS allocation inside ext3 transaction in
ext3_symlink().  Such allocation may re-enter ext3 code from
try_to_free_pages.  But JBD/ext3 code keeps a pointer to current journal
handle in task_struct and, hence, is not reentrable.

This bug led to "Assertion failure in journal_dirty_metadata()" messages.

http://bugzilla.openvz.org/show_bug.cgi?id=115

Signed-off-by: Andrey Savochkin <saw@saw.sw.com.sg>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Kirill Korotaev 2006-03-11 03:27:13 -08:00 committed by Linus Torvalds
parent 8bd0ee93fe
commit 0adb25d2e7
3 changed files with 15 additions and 3 deletions
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3
fs/ext3/namei.c
View File

@ -2141,7 +2141,8 @@ retry:
* We have a transaction open. All is sweetness. It also sets * We have a transaction open. All is sweetness. It also sets
* i_size in generic_commit_write(). * i_size in generic_commit_write().
*/ */
err = page_symlink(inode, symname, l); err = __page_symlink(inode, symname, l,
mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS);
if (err) { if (err) {
ext3_dec_count(handle, inode); ext3_dec_count(handle, inode);
ext3_mark_inode_dirty(handle, inode); ext3_mark_inode_dirty(handle, inode);

13
fs/namei.c
View File

@ -2613,13 +2613,15 @@ void page_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
} }
} }
int page_symlink(struct inode *inode, const char *symname, int len) int __page_symlink(struct inode *inode, const char *symname, int len,
gfp_t gfp_mask)
{ {
struct address_space *mapping = inode->i_mapping; struct address_space *mapping = inode->i_mapping;
struct page *page = grab_cache_page(mapping, 0); struct page *page;
int err = -ENOMEM; int err = -ENOMEM;
char *kaddr; char *kaddr;
page = find_or_create_page(mapping, 0, gfp_mask);
if (!page) if (!page)
goto fail; goto fail;
err = mapping->a_ops->prepare_write(NULL, page, 0, len-1); err = mapping->a_ops->prepare_write(NULL, page, 0, len-1);
@ -2654,6 +2656,12 @@ fail:
return err; return err;
} }
int page_symlink(struct inode *inode, const char *symname, int len)
{
return __page_symlink(inode, symname, len,
mapping_gfp_mask(inode->i_mapping));
}
struct inode_operations page_symlink_inode_operations = { struct inode_operations page_symlink_inode_operations = {
.readlink = generic_readlink, .readlink = generic_readlink,
.follow_link = page_follow_link_light, .follow_link = page_follow_link_light,
@ -2672,6 +2680,7 @@ EXPORT_SYMBOL(lookup_one_len);
EXPORT_SYMBOL(page_follow_link_light); EXPORT_SYMBOL(page_follow_link_light);
EXPORT_SYMBOL(page_put_link); EXPORT_SYMBOL(page_put_link);
EXPORT_SYMBOL(page_readlink); EXPORT_SYMBOL(page_readlink);
EXPORT_SYMBOL(__page_symlink);
EXPORT_SYMBOL(page_symlink); EXPORT_SYMBOL(page_symlink);
EXPORT_SYMBOL(page_symlink_inode_operations); EXPORT_SYMBOL(page_symlink_inode_operations);
EXPORT_SYMBOL(path_lookup); EXPORT_SYMBOL(path_lookup);

2
include/linux/fs.h
View File

@ -1664,6 +1664,8 @@ extern int vfs_follow_link(struct nameidata *, const char *);
extern int page_readlink(struct dentry *, char __user *, int); extern int page_readlink(struct dentry *, char __user *, int);
extern void *page_follow_link_light(struct dentry *, struct nameidata *); extern void *page_follow_link_light(struct dentry *, struct nameidata *);
extern void page_put_link(struct dentry *, struct nameidata *, void *); extern void page_put_link(struct dentry *, struct nameidata *, void *);
extern int __page_symlink(struct inode *inode, const char *symname, int len,
gfp_t gfp_mask);
extern int page_symlink(struct inode *inode, const char *symname, int len); extern int page_symlink(struct inode *inode, const char *symname, int len);
extern struct inode_operations page_symlink_inode_operations; extern struct inode_operations page_symlink_inode_operations;
extern int generic_readlink(struct dentry *, char __user *, int); extern int generic_readlink(struct dentry *, char __user *, int);