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authorFrederic Weisbecker <fweisbec@gmail.com>2009-12-30 09:12:03 +0300
committerFrederic Weisbecker <fweisbec@gmail.com>2010-01-02 03:57:32 +0300
commitc674905ca74ad0ae5b048afb1ef68663a0d7e987 (patch)
tree3f269bdda58519c012cf0505e36cee158ec7064b /fs/reiserfs/namei.c
parent3f14fea6bbd3444dd46a2af3a2e219e792616645 (diff)
downloadlinux-c674905ca74ad0ae5b048afb1ef68663a0d7e987.tar.xz
reiserfs: Fix unwanted recursive reiserfs lock in reiserfs_unlink()
reiserfs_unlink() may or may not be called under the reiserfs lock. But it also takes the reiserfs lock and can then acquire it recursively which leads to do_journal_begin_r() that fails to relax the reiserfs lock before grabbing the journal mutex, creating an unexpected lock inversion. We need to ensure reiserfs_unlink() won't get the reiserfs lock recursively using reiserfs_write_lock_once(). This fixes the following warning that precedes a lock inversion report (reiserfs lock <-> journal mutex). ------------[ cut here ]------------ WARNING: at fs/reiserfs/lock.c:95 reiserfs_lock_check_recursive+0x3a/0x50() Hardware name: MS-7418 Unwanted recursive reiserfs lock! Pid: 3208, comm: dbench Not tainted 2.6.32-atom #177 Call Trace: [<c114327a>] ? reiserfs_lock_check_recursive+0x3a/0x50 [<c114327a>] ? reiserfs_lock_check_recursive+0x3a/0x50 [<c10373a7>] warn_slowpath_common+0x67/0xc0 [<c114327a>] ? reiserfs_lock_check_recursive+0x3a/0x50 [<c1037446>] warn_slowpath_fmt+0x26/0x30 [<c114327a>] reiserfs_lock_check_recursive+0x3a/0x50 [<c113c213>] do_journal_begin_r+0x83/0x360 [<c105eb16>] ? __lock_acquire+0x1296/0x19e0 [<c1142a57>] ? xattr_unlink+0x57/0xb0 [<c113c670>] journal_begin+0x80/0x130 [<c1116d5d>] reiserfs_unlink+0x7d/0x2d0 [<c1142a57>] ? xattr_unlink+0x57/0xb0 [<c1142a57>] ? xattr_unlink+0x57/0xb0 [<c1142a57>] ? xattr_unlink+0x57/0xb0 [<c1142a64>] xattr_unlink+0x64/0xb0 [<c1143169>] delete_one_xattr+0x29/0x100 [<c11427ab>] reiserfs_for_each_xattr+0x10b/0x290 [<c1143140>] ? delete_one_xattr+0x0/0x100 [<c1401ca9>] ? mutex_lock_nested+0x299/0x340 [<c11429aa>] reiserfs_delete_xattrs+0x1a/0x60 [<c11432f9>] ? reiserfs_write_lock_once+0x29/0x50 [<c111ea1f>] reiserfs_delete_inode+0x9f/0x150 [<c11b0d0f>] ? _atomic_dec_and_lock+0x4f/0x70 [<c111e980>] ? reiserfs_delete_inode+0x0/0x150 [<c10c9c32>] generic_delete_inode+0xa2/0x170 [<c10c9d4f>] generic_drop_inode+0x4f/0x70 [<c10c8b07>] iput+0x47/0x50 [<c10c0965>] do_unlinkat+0xd5/0x160 [<c10505c6>] ? up_read+0x16/0x30 [<c1022ab7>] ? do_page_fault+0x187/0x330 [<c1002fd8>] ? restore_all_notrace+0x0/0x18 [<c1022930>] ? do_page_fault+0x0/0x330 [<c105cbe4>] ? trace_hardirqs_on_caller+0x124/0x170 [<c10c0a00>] sys_unlink+0x10/0x20 [<c1002ec4>] sysenter_do_call+0x12/0x32 ---[ end trace 2e35d71a6cc69d0c ]--- Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Christian Kujau <lists@nerdbynature.de> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'fs/reiserfs/namei.c')
-rw-r--r--fs/reiserfs/namei.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index e296ff72a6cc..9d4dcf0b07cb 100644
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -921,6 +921,7 @@ static int reiserfs_unlink(struct inode *dir, struct dentry *dentry)
struct reiserfs_transaction_handle th;
int jbegin_count;
unsigned long savelink;
+ int depth;
inode = dentry->d_inode;
@@ -932,7 +933,7 @@ static int reiserfs_unlink(struct inode *dir, struct dentry *dentry)
JOURNAL_PER_BALANCE_CNT * 2 + 2 +
4 * REISERFS_QUOTA_TRANS_BLOCKS(dir->i_sb);
- reiserfs_write_lock(dir->i_sb);
+ depth = reiserfs_write_lock_once(dir->i_sb);
retval = journal_begin(&th, dir->i_sb, jbegin_count);
if (retval)
goto out_unlink;
@@ -993,7 +994,7 @@ static int reiserfs_unlink(struct inode *dir, struct dentry *dentry)
retval = journal_end(&th, dir->i_sb, jbegin_count);
reiserfs_check_path(&path);
- reiserfs_write_unlock(dir->i_sb);
+ reiserfs_write_unlock_once(dir->i_sb, depth);
return retval;
end_unlink:
@@ -1003,7 +1004,7 @@ static int reiserfs_unlink(struct inode *dir, struct dentry *dentry)
if (err)
retval = err;
out_unlink:
- reiserfs_write_unlock(dir->i_sb);
+ reiserfs_write_unlock_once(dir->i_sb, depth);
return retval;
}