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authorJaegeuk Kim <jaegeuk@kernel.org>2014-12-18 19:32:36 -0800
committerJaegeuk Kim <jaegeuk@kernel.org>2015-01-09 17:02:25 -0800
commitdd802406e396c22dfb5aa0d16196f04d515be49e (patch)
treedd7c8361203983936bc6ef5f6c61234a69eadfd0
parentdb9f7c1a9561e998d6227bcc1c19bc4c1fbbca1b (diff)
f2fs: avoid double lock for cp_rwsem
The __f2fs_add_link is covered by cp_rwsem all the time. This calls init_inode_metadata, which conducts some acl operations including memory allocation with GFP_KERNEL previously. But, under memory pressure, f2fs_write_data_page can be called, which also grabs cp_rwsem too. In this case, this incurs a deadlock pointed by Chao. Thread #1 Thread #2 down_read down_write down_read -> here down_read should wait forever. Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
-rw-r--r--fs/f2fs/acl.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
index 1ccb26bc2a0b..7f12d28ad94c 100644
--- a/fs/f2fs/acl.c
+++ b/fs/f2fs/acl.c
@@ -62,7 +62,7 @@ static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
if (count == 0)
return NULL;
- acl = posix_acl_alloc(count, GFP_KERNEL);
+ acl = posix_acl_alloc(count, GFP_NOFS);
if (!acl)
return ERR_PTR(-ENOMEM);
@@ -116,7 +116,7 @@ static void *f2fs_acl_to_disk(const struct posix_acl *acl, size_t *size)
int i;
f2fs_acl = kmalloc(sizeof(struct f2fs_acl_header) + acl->a_count *
- sizeof(struct f2fs_acl_entry), GFP_KERNEL);
+ sizeof(struct f2fs_acl_entry), GFP_NOFS);
if (!f2fs_acl)
return ERR_PTR(-ENOMEM);