| Message ID | 20210325140339.6603-1-chandanrlinux@gmail.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | [1/2] xfs: Initialize xfs_alloc_arg->total correctly when allocating minlen extents | expand |
On Thu, Mar 25, 2021 at 07:33:38PM +0530, Chandan Babu R wrote: > xfs/538 can cause the following call trace to be printed when executing on a > multi-block directory configuration, > > WARNING: CPU: 1 PID: 2578 at fs/xfs/libxfs/xfs_bmap.c:717 xfs_bmap_extents_to_btree+0x520/0x5d0 > Call Trace: > ? xfs_buf_rele+0x4f/0x450 > xfs_bmap_add_extent_hole_real+0x747/0x960 > xfs_bmapi_allocate+0x39a/0x440 > xfs_bmapi_write+0x507/0x9e0 > xfs_da_grow_inode_int+0x1cd/0x330 > ? up+0x12/0x60 > xfs_dir2_grow_inode+0x62/0x110 > ? xfs_trans_log_inode+0x234/0x2d0 > xfs_dir2_sf_to_block+0x103/0x940 > ? xfs_dir2_sf_check+0x8c/0x210 > ? xfs_da_compname+0x19/0x30 > ? xfs_dir2_sf_lookup+0xd0/0x3d0 > xfs_dir2_sf_addname+0x10d/0x910 > xfs_dir_createname+0x1ad/0x210 > xfs_create+0x404/0x620 > xfs_generic_create+0x24c/0x320 > path_openat+0xda6/0x1030 > do_filp_open+0x88/0x130 > ? kmem_cache_alloc+0x50/0x210 > ? __cond_resched+0x16/0x40 > ? kmem_cache_alloc+0x50/0x210 > do_sys_openat2+0x97/0x150 > __x64_sys_creat+0x49/0x70 > do_syscall_64+0x33/0x40 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > This occurs because xfs_bmap_exact_minlen_extent_alloc() initializes > xfs_alloc_arg->total to xfs_bmalloca->minlen. In the context of > xfs_bmap_exact_minlen_extent_alloc(), xfs_bmalloca->minlen has a value of 1 > and hence the space allocator could choose an AG which has less than > xfs_bmalloca->total number of free blocks available. As the transaction > proceeds, one of the future space allocation requests could fail due to > non-availability of free blocks in the AG that was originally chosen. > > This commit fixes the bug by assigning xfs_alloc_arg->total to the value of > xfs_bmalloca->total. > > Fixes: 301519674699 ("xfs: Introduce error injection to allocate only minlen size extents for files") > Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com> Sounds resonable to me, I guess I'll give it a try... Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D > --- > fs/xfs/libxfs/xfs_bmap.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c > index e0905ad171f0..585f7e795023 100644 > --- a/fs/xfs/libxfs/xfs_bmap.c > +++ b/fs/xfs/libxfs/xfs_bmap.c > @@ -3586,7 +3586,8 @@ xfs_bmap_exact_minlen_extent_alloc( > args.fsbno = ap->blkno; > args.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE; > args.type = XFS_ALLOCTYPE_FIRST_AG; > - args.total = args.minlen = args.maxlen = ap->minlen; > + args.minlen = args.maxlen = ap->minlen; > + args.total = ap->total; > > args.alignment = 1; > args.minalignslop = 0; > -- > 2.29.2 >
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index e0905ad171f0..585f7e795023 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -3586,7 +3586,8 @@ xfs_bmap_exact_minlen_extent_alloc( args.fsbno = ap->blkno; args.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE; args.type = XFS_ALLOCTYPE_FIRST_AG; - args.total = args.minlen = args.maxlen = ap->minlen; + args.minlen = args.maxlen = ap->minlen; + args.total = ap->total; args.alignment = 1; args.minalignslop = 0;
xfs/538 can cause the following call trace to be printed when executing on a multi-block directory configuration, WARNING: CPU: 1 PID: 2578 at fs/xfs/libxfs/xfs_bmap.c:717 xfs_bmap_extents_to_btree+0x520/0x5d0 Call Trace: ? xfs_buf_rele+0x4f/0x450 xfs_bmap_add_extent_hole_real+0x747/0x960 xfs_bmapi_allocate+0x39a/0x440 xfs_bmapi_write+0x507/0x9e0 xfs_da_grow_inode_int+0x1cd/0x330 ? up+0x12/0x60 xfs_dir2_grow_inode+0x62/0x110 ? xfs_trans_log_inode+0x234/0x2d0 xfs_dir2_sf_to_block+0x103/0x940 ? xfs_dir2_sf_check+0x8c/0x210 ? xfs_da_compname+0x19/0x30 ? xfs_dir2_sf_lookup+0xd0/0x3d0 xfs_dir2_sf_addname+0x10d/0x910 xfs_dir_createname+0x1ad/0x210 xfs_create+0x404/0x620 xfs_generic_create+0x24c/0x320 path_openat+0xda6/0x1030 do_filp_open+0x88/0x130 ? kmem_cache_alloc+0x50/0x210 ? __cond_resched+0x16/0x40 ? kmem_cache_alloc+0x50/0x210 do_sys_openat2+0x97/0x150 __x64_sys_creat+0x49/0x70 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xae This occurs because xfs_bmap_exact_minlen_extent_alloc() initializes xfs_alloc_arg->total to xfs_bmalloca->minlen. In the context of xfs_bmap_exact_minlen_extent_alloc(), xfs_bmalloca->minlen has a value of 1 and hence the space allocator could choose an AG which has less than xfs_bmalloca->total number of free blocks available. As the transaction proceeds, one of the future space allocation requests could fail due to non-availability of free blocks in the AG that was originally chosen. This commit fixes the bug by assigning xfs_alloc_arg->total to the value of xfs_bmalloca->total. Fixes: 301519674699 ("xfs: Introduce error injection to allocate only minlen size extents for files") Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com> --- fs/xfs/libxfs/xfs_bmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)