aboutsummaryrefslogtreecommitdiffstats
path: root/fs
diff options
context:
space:
mode:
authorFrederic Weisbecker <fweisbec@gmail.com>2010-09-30 15:15:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-01 10:50:59 -0700
commit9d8117e72bf453dd9d85e0cd322ce4a0f8bccbc0 (patch)
treeb04c93fa9d41db9802c576f8dfaf74edb42ebc60 /fs
parent3f259d092c7a2fdf217823e8f1838530adb0cdb0 (diff)
downloadmrst-s0i3-test-9d8117e72bf453dd9d85e0cd322ce4a0f8bccbc0.tar.gz
mrst-s0i3-test-9d8117e72bf453dd9d85e0cd322ce4a0f8bccbc0.tar.xz
mrst-s0i3-test-9d8117e72bf453dd9d85e0cd322ce4a0f8bccbc0.zip
reiserfs: fix unwanted reiserfs lock recursion
Prevent from recursively locking the reiserfs lock in reiserfs_unpack() because we may call journal_begin() that requires the lock to be taken only once, otherwise it won't be able to release the lock while taking other mutexes, ending up in inverted dependencies between the journal mutex and the reiserfs lock for example. This fixes: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.35.4.4a #3 ------------------------------------------------------- lilo/1620 is trying to acquire lock: (&journal->j_mutex){+.+...}, at: [<d0325bff>] do_journal_begin_r+0x7f/0x340 [reiserfs] but task is already holding lock: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<d032a278>] reiserfs_write_lock+0x28/0x40 [reiserfs] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&REISERFS_SB(s)->lock){+.+.+.}: [<c10562b7>] lock_acquire+0x67/0x80 [<c12facad>] __mutex_lock_common+0x4d/0x410 [<c12fb0c8>] mutex_lock_nested+0x18/0x20 [<d032a278>] reiserfs_write_lock+0x28/0x40 [reiserfs] [<d0325c06>] do_journal_begin_r+0x86/0x340 [reiserfs] [<d0325f77>] journal_begin+0x77/0x140 [reiserfs] [<d0315be4>] reiserfs_remount+0x224/0x530 [reiserfs] [<c10b6a20>] do_remount_sb+0x60/0x110 [<c10cee25>] do_mount+0x625/0x790 [<c10cf014>] sys_mount+0x84/0xb0 [<c12fca3d>] syscall_call+0x7/0xb -> #0 (&journal->j_mutex){+.+...}: [<c10560f6>] __lock_acquire+0x1026/0x1180 [<c10562b7>] lock_acquire+0x67/0x80 [<c12facad>] __mutex_lock_common+0x4d/0x410 [<c12fb0c8>] mutex_lock_nested+0x18/0x20 [<d0325bff>] do_journal_begin_r+0x7f/0x340 [reiserfs] [<d0325f77>] journal_begin+0x77/0x140 [reiserfs] [<d0326271>] reiserfs_persistent_transaction+0x41/0x90 [reiserfs] [<d030d06c>] reiserfs_get_block+0x22c/0x1530 [reiserfs] [<c10db9db>] __block_prepare_write+0x1bb/0x3a0 [<c10dbbe6>] block_prepare_write+0x26/0x40 [<d030b738>] reiserfs_prepare_write+0x88/0x170 [reiserfs] [<d03294d6>] reiserfs_unpack+0xe6/0x120 [reiserfs] [<d0329782>] reiserfs_ioctl+0x272/0x320 [reiserfs] [<c10c3188>] vfs_ioctl+0x28/0xa0 [<c10c3bbd>] do_vfs_ioctl+0x32d/0x5c0 [<c10c3eb3>] sys_ioctl+0x63/0x70 [<c12fca3d>] syscall_call+0x7/0xb other info that might help us debug this: 2 locks held by lilo/1620: #0: (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [<d032945a>] reiserfs_unpack+0x6a/0x120 [reiserfs] #1: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<d032a278>] reiserfs_write_lock+0x28/0x40 [reiserfs] stack backtrace: Pid: 1620, comm: lilo Not tainted 2.6.35.4.4a #3 Call Trace: [<c10560f6>] __lock_acquire+0x1026/0x1180 [<c10562b7>] lock_acquire+0x67/0x80 [<c12facad>] __mutex_lock_common+0x4d/0x410 [<c12fb0c8>] mutex_lock_nested+0x18/0x20 [<d0325bff>] do_journal_begin_r+0x7f/0x340 [reiserfs] [<d0325f77>] journal_begin+0x77/0x140 [reiserfs] [<d0326271>] reiserfs_persistent_transaction+0x41/0x90 [reiserfs] [<d030d06c>] reiserfs_get_block+0x22c/0x1530 [reiserfs] [<c10db9db>] __block_prepare_write+0x1bb/0x3a0 [<c10dbbe6>] block_prepare_write+0x26/0x40 [<d030b738>] reiserfs_prepare_write+0x88/0x170 [reiserfs] [<d03294d6>] reiserfs_unpack+0xe6/0x120 [reiserfs] [<d0329782>] reiserfs_ioctl+0x272/0x320 [reiserfs] [<c10c3188>] vfs_ioctl+0x28/0xa0 [<c10c3bbd>] do_vfs_ioctl+0x32d/0x5c0 [<c10c3eb3>] sys_ioctl+0x63/0x70 [<c12fca3d>] syscall_call+0x7/0xb Reported-by: Jarek Poplawski <jarkao2@gmail.com> Tested-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: All since 2.6.32 <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/reiserfs/ioctl.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/reiserfs/ioctl.c b/fs/reiserfs/ioctl.c
index 679d5029f50..5cbb81e134a 100644
--- a/fs/reiserfs/ioctl.c
+++ b/fs/reiserfs/ioctl.c
@@ -170,6 +170,7 @@ int reiserfs_prepare_write(struct file *f, struct page *page,
int reiserfs_unpack(struct inode *inode, struct file *filp)
{
int retval = 0;
+ int depth;
int index;
struct page *page;
struct address_space *mapping;
@@ -189,7 +190,7 @@ int reiserfs_unpack(struct inode *inode, struct file *filp)
** us
*/
reiserfs_mutex_lock_safe(&inode->i_mutex, inode->i_sb);
- reiserfs_write_lock(inode->i_sb);
+ depth = reiserfs_write_lock_once(inode->i_sb);
write_from = inode->i_size & (blocksize - 1);
/* if we are on a block boundary, we are already unpacked. */
@@ -224,6 +225,6 @@ int reiserfs_unpack(struct inode *inode, struct file *filp)
out:
mutex_unlock(&inode->i_mutex);
- reiserfs_write_unlock(inode->i_sb);
+ reiserfs_write_unlock_once(inode->i_sb, depth);
return retval;
}