[PATCH] ext3: ext3_symlink should use GFP_NOFS allocations inside
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>
diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c
index 8bd8ac0..b8f5cd1 100644
--- a/fs/ext3/namei.c
+++ b/fs/ext3/namei.c
@@ -2141,7 +2141,8 @@
* We have a transaction open. All is sweetness. It also sets
* 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) {
ext3_dec_count(handle, inode);
ext3_mark_inode_dirty(handle, inode);
diff --git a/fs/namei.c b/fs/namei.c
index 557dcf3..8dc2b03 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2613,13 +2613,15 @@
}
}
-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 page *page = grab_cache_page(mapping, 0);
+ struct page *page;
int err = -ENOMEM;
char *kaddr;
+ page = find_or_create_page(mapping, 0, gfp_mask);
if (!page)
goto fail;
err = mapping->a_ops->prepare_write(NULL, page, 0, len-1);
@@ -2654,6 +2656,12 @@
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 = {
.readlink = generic_readlink,
.follow_link = page_follow_link_light,
@@ -2672,6 +2680,7 @@
EXPORT_SYMBOL(page_follow_link_light);
EXPORT_SYMBOL(page_put_link);
EXPORT_SYMBOL(page_readlink);
+EXPORT_SYMBOL(__page_symlink);
EXPORT_SYMBOL(page_symlink);
EXPORT_SYMBOL(page_symlink_inode_operations);
EXPORT_SYMBOL(path_lookup);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 51c0c93..128d008 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1664,6 +1664,8 @@
extern int page_readlink(struct dentry *, char __user *, int);
extern void *page_follow_link_light(struct dentry *, struct nameidata *);
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 struct inode_operations page_symlink_inode_operations;
extern int generic_readlink(struct dentry *, char __user *, int);