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| author | Jan Kara <jack@suse.cz> | 2013-12-23 22:02:16 +0100 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2013-12-23 22:02:16 +0100 |
| commit | 4ea7772f828a2f1cf6fbf96a3e6f99ae149d2724 (patch) | |
| tree | 2515839eb42739317490f2365ea303435ea236f3 /fs | |
| parent | jbd: Revise KERN_EMERG error messages (diff) | |
| download | linux-4ea7772f828a2f1cf6fbf96a3e6f99ae149d2724.tar.xz linux-4ea7772f828a2f1cf6fbf96a3e6f99ae149d2724.zip | |
udf: Fix lockdep warning from udf_symlink()
Lockdep is complaining about UDF:
=============================================
[ INFO: possible recursive locking detected ]
3.12.0+ #16 Not tainted
---------------------------------------------
ln/7386 is trying to acquire lock:
(&ei->i_data_sem){+.+...}, at: [<ffffffff8142f06d>] udf_get_block+0x8d/0x130
but task is already holding lock:
(&ei->i_data_sem){+.+...}, at: [<ffffffff81431a8d>] udf_symlink+0x8d/0x690
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&ei->i_data_sem);
lock(&ei->i_data_sem);
*** DEADLOCK ***
This is because we hold i_data_sem of the symlink inode while calling
udf_add_entry() for the directory. I don't think this can ever lead to
deadlocks since we never hold i_data_sem for two inodes in any other
place.
The fix is simple - move unlock of i_data_sem for symlink inode up. We
don't need it for anything when linking symlink inode to directory.
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/udf/namei.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/udf/namei.c b/fs/udf/namei.c index 5f6fc17d6bc5..9737cba1357d 100644 --- a/fs/udf/namei.c +++ b/fs/udf/namei.c @@ -1010,6 +1010,7 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry, else udf_truncate_tail_extent(inode); mark_inode_dirty(inode); + up_write(&iinfo->i_data_sem); fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err); if (!fi) @@ -1023,7 +1024,6 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry, udf_write_fi(dir, &cfi, fi, &fibh, NULL, NULL); if (UDF_I(dir)->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) mark_inode_dirty(dir); - up_write(&iinfo->i_data_sem); if (fibh.sbh != fibh.ebh) brelse(fibh.ebh); brelse(fibh.sbh); |