XFS: memory leak in xfs_inactive() - is xfs_trans_free() enough or do we need xfs_trans_cancel() ?
RFC PATCH 1/1 XFS: memory leak in xfs_inactive() - is xfs_trans_free() enough or do we need xfs_trans_cancel() ?
Hi,
The Coverity checker found a memory leak in xfs_inactive().
The offending code is this bit :
1671 tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
At conditional (1): "truncate != 0" taking true path
1672 if (truncate) {
1673 /*
1674 * Do the xfs_itruncate_start() call before
1675 * reserving any log space because itruncate_start
1676 * will call into the buffer cache and we can't
1677 * do that within a transaction.
1678 */
1679 xfs_ilock(ip, XFS_IOLOCK_EXCL);
1680
1681 error = xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, 0);
At conditional (2): "error != 0" taking true path
1682 if (error) {
1683 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
Event leaked_storage: Returned without freeing storage "tp" Also see events: [alloc_fn][var_assign]
1684 return VN_INACTIVE_CACHE;
1685 }
So, the code allocates a transaction, but in the case where 'truncate' is !=0 and xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, 0); happens to return an error, we'll just return from the function without dealing with the memory allocated byxfs_trans_alloc() and assigned to 'tp', thus it'll be orphaned/leaked - not good.
What I'm wondering is this; is it enough, at this point, to call xfs_trans_free(tp); (it would seem to me that would be OK, but I'm not intimite with this code) or do we need a full xfs_trans_cancel(tp, 0); ???
In case I'm right and xfs_trans_free(tp); is all we need, then please consider the patch below. Otherwise please NACK the patch and I'll cook up another one :-)
Fix memory leak on error in xfs_inactive().
---
fs/xfs/xfs_vnodeops.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
fs/xfs/xfs_vnodeops.c +1 -0
@@ -1681,6 +1681,7 @@ xfs_inactive( error =xfs_itruncate_start (ip,XFS_ITRUNC_DEFINITE ,0 );if (error) {xfs_iunlock (ip,XFS_IOLOCK_EXCL ); +xfs_trans_free (tp);return VN_INACTIVE_CACHE ; }
Signature · 3 lines
Jesper Juhl <[email protected]> Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html Plain text mails only, please http://www.expita.com/nomime.html
Quoted 3 lines · Jesper Juhl
Hi,
The Coverity checker found a memory leak in
xfs_inactive().
....
Quoted 5 lines
So, the code allocates a transaction, but in the case where 'truncate' is !=0 and
xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, 0); happens to return an error, we'll just return from the function without dealing with the memory allocatedbyxfs_trans_alloc()and assigned to 'tp', thus it'll be orphaned/leaked - not good.
Yeah, introduced by:
Thanks for reporting the problem, Jesper.
Quoted 3 lines
What I'm wondering is this; is it enough, at this point, to call
xfs_trans_free(tp); (it would seem to me that would be OK, but I'm not intimite with this code) or do we need a fullxfs_trans_cancel(tp, 0); ???
xfs_trans_free() is not supposed to be called by anything but the transaction code (it's static). So a xfs_trans_cancel() would need to be issued.
Quoted 3 lines
In case I'm right and
xfs_trans_free(tp); is all we need, then please consider the patch below. Otherwise please NACK the patch and I'll cook up another one :-)
NACK ;)
xfs_trans_cancel() is needed. Patch below.
Cheers,
Dave.
Signature · 20 lines
Dave Chinner
Principal Engineer
SGI Australian Software Group
---
fs/xfs/xfs_vnodeops.c | 1 +
1 file changed, 1 insertion(+)
Index: 2.6.x-xfs-new/fs/xfs/xfs_vnodeops.c
===================================================================
--- 2.6.x-xfs-new.orig/fs/xfs/xfs_vnodeops.c 2007-05-11 16:04:03.000000000 +1000
+++ 2.6.x-xfs-new/fs/xfs/xfs_vnodeops.c 2007-05-17 12:37:25.671399078 +1000
@@ -1710,6 +1710,7 @@ xfs_inactive(
error = xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, 0);
if (error) {
+ xfs_trans_cancel(tp, 0);
xfs_iunlock(ip, XFS_IOLOCK_EXCL);
return VN_INACTIVE_CACHE;
}Quoted 11 lines · On Thursday 17 May 2007 04:40:24 David Chinner wrote:
Quoted 3 lines · Jesper Juhl
Hi,
The Coverity checker found a memory leak in
xfs_inactive().....
Quoted 5 lines
So, the code allocates a transaction, but in the case where 'truncate' is !=0 and
xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, 0); happens to return an error, we'll just return from the function without dealing with the memory allocatedbyxfs_trans_alloc()and assigned to 'tp', thus it'll be orphaned/leaked - not good.
Quoted 6 lines
Yeah, introduced by:
Thanks for reporting the problem, Jesper.
You are welcome.
That commit introduces the same problem in xfs_inactive_free_eofblocks(). Patch to fix it below.
Quoted 7 lines
Quoted 3 lines
What I'm wondering is this; is it enough, at this point, to call
xfs_trans_free(tp); (it would seem to me that would be OK, but I'm not intimite with this code) or do we need a fullxfs_trans_cancel(tp, 0); ???
xfs_trans_free()is not supposed to be called by anything but the transaction code (it's static). So axfs_trans_cancel()would need to be issued.
Makes sense. Thanks. I completely missed the static nature :-/
Fix XFS memory leak; allocated transaction not freed in xfs_inactive_free_eofblocks() in failure case.
---
fs/xfs/xfs_vnodeops.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
fs/xfs/xfs_vnodeops.c +1 -0
@@ -1260,6 +1260,7 @@ xfs_inactive_free_eofblocks( error =xfs_itruncate_start (ip,XFS_ITRUNC_DEFINITE , ip->i_size);if (error) { +xfs_trans_cancel (tp,0 );xfs_iunlock (ip,XFS_IOLOCK_EXCL );return error; }
Any chance the patches below that fix two mem leaks in XFS will make it in in time for 2.6.22? I believe they should...
Quoted 55 lines · Jesper Juhl
Quoted 11 lines · On Thursday 17 May 2007 04:40:24 David Chinner wrote:
Quoted 3 lines · Jesper Juhl
Hi,
The Coverity checker found a memory leak in
xfs_inactive().....
Quoted 5 lines
So, the code allocates a transaction, but in the case where 'truncate' is !=0 and
xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, 0); happens to return an error, we'll just return from the function without dealing with the memory allocatedbyxfs_trans_alloc()and assigned to 'tp', thus it'll be orphaned/leaked - not good.Quoted 6 lines
Yeah, introduced by:
Thanks for reporting the problem, Jesper.
You are welcome.
That commit introduces the same problem in
xfs_inactive_free_eofblocks(). Patch to fix it below.Quoted 7 lines
Quoted 3 lines
What I'm wondering is this; is it enough, at this point, to call
xfs_trans_free(tp); (it would seem to me that would be OK, but I'm not intimite with this code) or do we need a fullxfs_trans_cancel(tp, 0); ???
xfs_trans_free()is not supposed to be called by anything but the transaction code (it's static). So axfs_trans_cancel()would need to be issued.Makes sense. Thanks. I completely missed the static nature :-/
Fix XFS memory leak; allocated transaction not freed in
xfs_inactive_free_eofblocks()in failure case.Signed-off-by Jesper Juhl <[email protected]>--- fs/xfs/xfs_vnodeops.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)fs/xfs/xfs_vnodeops.c +1
-0@@ -1260,6 +1260,7 @@ xfs_inactive_free_eofblocks( error =xfs_itruncate_start (ip,XFS_ITRUNC_DEFINITE , ip->i_size);if (error) { +xfs_trans_cancel (tp,0 );xfs_iunlock (ip,XFS_IOLOCK_EXCL );return error; }
Signature · 3 lines
Jesper Juhl <[email protected]> Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html Plain text mails only, please http://www.expita.com/nomime.html