This series backports two patches which fix known bugs in the xfs filesystem code to the v4.14.y stable tree.
They are each verified by the xfs tests xfs/439 and generic/585 respectively.
The first patch applies cleanly.
The second patch required slight massage due to the last code block being removed having changed slightly upstream due to rework. I think the backport is functionally equivalent. Only thing is I request comment that it is correct to use the following error path:
ASSERT(VFS_I(wip)->i_nlink == 0); error = xfs_iunlink_remove(tp, wip); if (error)
goto out_trans_cancel;
The old error patch out_bmap_cancel still exists here. However as nothing can have modified the deferred ops struct at this point I believe it is sufficient to go to the "out_trans_cancel" error label.
Darrick J. Wong (1): xfs: validate sb_logsunit is a multiple of the fs blocksize
kaixuxia (1): xfs: Fix deadlock between AGI and AGF with RENAME_WHITEOUT
fs/xfs/xfs_inode.c | 85 +++++++++++++++++++++++----------------------- fs/xfs/xfs_log.c | 14 +++++++- 2 files changed, 55 insertions(+), 44 deletions(-)
From: "Darrick J. Wong" darrick.wong@oracle.com
commit 9c92ee208b1faa0ef2cc899b85fd0607b6fac7fe upstream.
Make sure the log stripe unit is sane before proceeding with mounting. AFAICT this means that logsunit has to be 0, 1, or a multiple of the fs block size. Found this by setting the LSB of logsunit in xfs/350 and watching the system crash as soon as we try to write to the log.
Signed-off-by: Darrick J. Wong darrick.wong@oracle.com Reviewed-by: Brian Foster bfoster@redhat.com Signed-off-by: Suraj Jitindar Singh surajjs@amazon.com --- fs/xfs/xfs_log.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 4e768e606998..360e32220f93 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -608,6 +608,7 @@ xfs_log_mount( xfs_daddr_t blk_offset, int num_bblks) { + bool fatal = xfs_sb_version_hascrc(&mp->m_sb); int error = 0; int min_logfsbs;
@@ -659,9 +660,20 @@ xfs_log_mount( XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks), XFS_MAX_LOG_BYTES); error = -EINVAL; + } else if (mp->m_sb.sb_logsunit > 1 && + mp->m_sb.sb_logsunit % mp->m_sb.sb_blocksize) { + xfs_warn(mp, + "log stripe unit %u bytes must be a multiple of block size", + mp->m_sb.sb_logsunit); + error = -EINVAL; + fatal = true; } if (error) { - if (xfs_sb_version_hascrc(&mp->m_sb)) { + /* + * Log check errors are always fatal on v5; or whenever bad + * metadata leads to a crash. + */ + if (fatal) { xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!"); ASSERT(0); goto out_free_log;
From: kaixuxia xiakaixu1987@gmail.com
commit bc56ad8c74b8588685c2875de0df8ab6974828ef upstream.
When performing rename operation with RENAME_WHITEOUT flag, we will hold AGF lock to allocate or free extents in manipulating the dirents firstly, and then doing the xfs_iunlink_remove() call last to hold AGI lock to modify the tmpfile info, so we the lock order AGI->AGF.
The big problem here is that we have an ordering constraint on AGF and AGI locking - inode allocation locks the AGI, then can allocate a new extent for new inodes, locking the AGF after the AGI. Hence the ordering that is imposed by other parts of the code is AGI before AGF. So we get an ABBA deadlock between the AGI and AGF here.
Process A: Call trace: ? __schedule+0x2bd/0x620 schedule+0x33/0x90 schedule_timeout+0x17d/0x290 __down_common+0xef/0x125 ? xfs_buf_find+0x215/0x6c0 [xfs] down+0x3b/0x50 xfs_buf_lock+0x34/0xf0 [xfs] xfs_buf_find+0x215/0x6c0 [xfs] xfs_buf_get_map+0x37/0x230 [xfs] xfs_buf_read_map+0x29/0x190 [xfs] xfs_trans_read_buf_map+0x13d/0x520 [xfs] xfs_read_agf+0xa6/0x180 [xfs] ? schedule_timeout+0x17d/0x290 xfs_alloc_read_agf+0x52/0x1f0 [xfs] xfs_alloc_fix_freelist+0x432/0x590 [xfs] ? down+0x3b/0x50 ? xfs_buf_lock+0x34/0xf0 [xfs] ? xfs_buf_find+0x215/0x6c0 [xfs] xfs_alloc_vextent+0x301/0x6c0 [xfs] xfs_ialloc_ag_alloc+0x182/0x700 [xfs] ? _xfs_trans_bjoin+0x72/0xf0 [xfs] xfs_dialloc+0x116/0x290 [xfs] xfs_ialloc+0x6d/0x5e0 [xfs] ? xfs_log_reserve+0x165/0x280 [xfs] xfs_dir_ialloc+0x8c/0x240 [xfs] xfs_create+0x35a/0x610 [xfs] xfs_generic_create+0x1f1/0x2f0 [xfs] ...
Process B: Call trace: ? __schedule+0x2bd/0x620 ? xfs_bmapi_allocate+0x245/0x380 [xfs] schedule+0x33/0x90 schedule_timeout+0x17d/0x290 ? xfs_buf_find+0x1fd/0x6c0 [xfs] __down_common+0xef/0x125 ? xfs_buf_get_map+0x37/0x230 [xfs] ? xfs_buf_find+0x215/0x6c0 [xfs] down+0x3b/0x50 xfs_buf_lock+0x34/0xf0 [xfs] xfs_buf_find+0x215/0x6c0 [xfs] xfs_buf_get_map+0x37/0x230 [xfs] xfs_buf_read_map+0x29/0x190 [xfs] xfs_trans_read_buf_map+0x13d/0x520 [xfs] xfs_read_agi+0xa8/0x160 [xfs] xfs_iunlink_remove+0x6f/0x2a0 [xfs] ? current_time+0x46/0x80 ? xfs_trans_ichgtime+0x39/0xb0 [xfs] xfs_rename+0x57a/0xae0 [xfs] xfs_vn_rename+0xe4/0x150 [xfs] ...
In this patch we move the xfs_iunlink_remove() call to before acquiring the AGF lock to preserve correct AGI/AGF locking order.
Signed-off-by: kaixuxia kaixuxia@tencent.com Reviewed-by: Brian Foster bfoster@redhat.com Reviewed-by: Darrick J. Wong darrick.wong@oracle.com Signed-off-by: Darrick J. Wong darrick.wong@oracle.com
Minor massage required to backport to apply due to removal of out_bmap_cancel: error path label upstream as a result of code rework. Only change was to the last code block removed by the patch. Functionally equivalent to upstream.
Signed-off-by: Suraj Jitindar Singh surajjs@amazon.com --- fs/xfs/xfs_inode.c | 85 +++++++++++++++++++++++----------------------- 1 file changed, 42 insertions(+), 43 deletions(-)
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index cb4833d06467..7cfbe2b0f886 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -3035,7 +3035,8 @@ xfs_rename( &dfops, &first_block, spaceres);
/* - * Set up the target. + * Check for expected errors before we dirty the transaction + * so we can return an error without a transaction abort. */ if (target_ip == NULL) { /* @@ -3047,6 +3048,46 @@ xfs_rename( if (error) goto out_trans_cancel; } + } else { + /* + * If target exists and it's a directory, check that whether + * it can be destroyed. + */ + if (S_ISDIR(VFS_I(target_ip)->i_mode) && + (!xfs_dir_isempty(target_ip) || + (VFS_I(target_ip)->i_nlink > 2))) { + error = -EEXIST; + goto out_trans_cancel; + } + } + + /* + * Directory entry creation below may acquire the AGF. Remove + * the whiteout from the unlinked list first to preserve correct + * AGI/AGF locking order. This dirties the transaction so failures + * after this point will abort and log recovery will clean up the + * mess. + * + * For whiteouts, we need to bump the link count on the whiteout + * inode. After this point, we have a real link, clear the tmpfile + * state flag from the inode so it doesn't accidentally get misused + * in future. + */ + if (wip) { + ASSERT(VFS_I(wip)->i_nlink == 0); + error = xfs_iunlink_remove(tp, wip); + if (error) + goto out_trans_cancel; + + xfs_bumplink(tp, wip); + xfs_trans_log_inode(tp, wip, XFS_ILOG_CORE); + VFS_I(wip)->i_state &= ~I_LINKABLE; + } + + /* + * Set up the target. + */ + if (target_ip == NULL) { /* * If target does not exist and the rename crosses * directories, adjust the target directory link count @@ -3067,22 +3108,6 @@ xfs_rename( goto out_bmap_cancel; } } else { /* target_ip != NULL */ - /* - * If target exists and it's a directory, check that both - * target and source are directories and that target can be - * destroyed, or that neither is a directory. - */ - if (S_ISDIR(VFS_I(target_ip)->i_mode)) { - /* - * Make sure target dir is empty. - */ - if (!(xfs_dir_isempty(target_ip)) || - (VFS_I(target_ip)->i_nlink > 2)) { - error = -EEXIST; - goto out_trans_cancel; - } - } - /* * Link the source inode under the target name. * If the source inode is a directory and we are moving @@ -3175,32 +3200,6 @@ xfs_rename( if (error) goto out_bmap_cancel;
- /* - * For whiteouts, we need to bump the link count on the whiteout inode. - * This means that failures all the way up to this point leave the inode - * on the unlinked list and so cleanup is a simple matter of dropping - * the remaining reference to it. If we fail here after bumping the link - * count, we're shutting down the filesystem so we'll never see the - * intermediate state on disk. - */ - if (wip) { - ASSERT(VFS_I(wip)->i_nlink == 0); - error = xfs_bumplink(tp, wip); - if (error) - goto out_bmap_cancel; - error = xfs_iunlink_remove(tp, wip); - if (error) - goto out_bmap_cancel; - xfs_trans_log_inode(tp, wip, XFS_ILOG_CORE); - - /* - * Now we have a real link, clear the "I'm a tmpfile" state - * flag from the inode so it doesn't accidentally get misused in - * future. - */ - VFS_I(wip)->i_state &= ~I_LINKABLE; - } - xfs_trans_ichgtime(tp, src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE); if (new_parent)
On Fri, Apr 24, 2020 at 04:05:32PM -0700, Suraj Jitindar Singh wrote:
From: kaixuxia xiakaixu1987@gmail.com
commit bc56ad8c74b8588685c2875de0df8ab6974828ef upstream.
When performing rename operation with RENAME_WHITEOUT flag, we will hold AGF lock to allocate or free extents in manipulating the dirents firstly, and then doing the xfs_iunlink_remove() call last to hold AGI lock to modify the tmpfile info, so we the lock order AGI->AGF.
The big problem here is that we have an ordering constraint on AGF and AGI locking - inode allocation locks the AGI, then can allocate a new extent for new inodes, locking the AGF after the AGI. Hence the ordering that is imposed by other parts of the code is AGI before AGF. So we get an ABBA deadlock between the AGI and AGF here.
Process A: Call trace: ? __schedule+0x2bd/0x620 schedule+0x33/0x90 schedule_timeout+0x17d/0x290 __down_common+0xef/0x125 ? xfs_buf_find+0x215/0x6c0 [xfs] down+0x3b/0x50 xfs_buf_lock+0x34/0xf0 [xfs] xfs_buf_find+0x215/0x6c0 [xfs] xfs_buf_get_map+0x37/0x230 [xfs] xfs_buf_read_map+0x29/0x190 [xfs] xfs_trans_read_buf_map+0x13d/0x520 [xfs] xfs_read_agf+0xa6/0x180 [xfs] ? schedule_timeout+0x17d/0x290 xfs_alloc_read_agf+0x52/0x1f0 [xfs] xfs_alloc_fix_freelist+0x432/0x590 [xfs] ? down+0x3b/0x50 ? xfs_buf_lock+0x34/0xf0 [xfs] ? xfs_buf_find+0x215/0x6c0 [xfs] xfs_alloc_vextent+0x301/0x6c0 [xfs] xfs_ialloc_ag_alloc+0x182/0x700 [xfs] ? _xfs_trans_bjoin+0x72/0xf0 [xfs] xfs_dialloc+0x116/0x290 [xfs] xfs_ialloc+0x6d/0x5e0 [xfs] ? xfs_log_reserve+0x165/0x280 [xfs] xfs_dir_ialloc+0x8c/0x240 [xfs] xfs_create+0x35a/0x610 [xfs] xfs_generic_create+0x1f1/0x2f0 [xfs] ...
Process B: Call trace: ? __schedule+0x2bd/0x620 ? xfs_bmapi_allocate+0x245/0x380 [xfs] schedule+0x33/0x90 schedule_timeout+0x17d/0x290 ? xfs_buf_find+0x1fd/0x6c0 [xfs] __down_common+0xef/0x125 ? xfs_buf_get_map+0x37/0x230 [xfs] ? xfs_buf_find+0x215/0x6c0 [xfs] down+0x3b/0x50 xfs_buf_lock+0x34/0xf0 [xfs] xfs_buf_find+0x215/0x6c0 [xfs] xfs_buf_get_map+0x37/0x230 [xfs] xfs_buf_read_map+0x29/0x190 [xfs] xfs_trans_read_buf_map+0x13d/0x520 [xfs] xfs_read_agi+0xa8/0x160 [xfs] xfs_iunlink_remove+0x6f/0x2a0 [xfs] ? current_time+0x46/0x80 ? xfs_trans_ichgtime+0x39/0xb0 [xfs] xfs_rename+0x57a/0xae0 [xfs] xfs_vn_rename+0xe4/0x150 [xfs] ...
In this patch we move the xfs_iunlink_remove() call to before acquiring the AGF lock to preserve correct AGI/AGF locking order.
Signed-off-by: kaixuxia kaixuxia@tencent.com Reviewed-by: Brian Foster bfoster@redhat.com Reviewed-by: Darrick J. Wong darrick.wong@oracle.com Signed-off-by: Darrick J. Wong darrick.wong@oracle.com
Minor massage required to backport to apply due to removal of out_bmap_cancel: error path label upstream as a result of code rework. Only change was to the last code block removed by the patch. Functionally equivalent to upstream.
This patch also needs to be backported to 4.19. I can look into that tomorrow unless you can send a patch sooner :)
From: kaixuxia xiakaixu1987@gmail.com
commit bc56ad8c74b8588685c2875de0df8ab6974828ef upstream.
When performing rename operation with RENAME_WHITEOUT flag, we will hold AGF lock to allocate or free extents in manipulating the dirents firstly, and then doing the xfs_iunlink_remove() call last to hold AGI lock to modify the tmpfile info, so we the lock order AGI->AGF.
The big problem here is that we have an ordering constraint on AGF and AGI locking - inode allocation locks the AGI, then can allocate a new extent for new inodes, locking the AGF after the AGI. Hence the ordering that is imposed by other parts of the code is AGI before AGF. So we get an ABBA deadlock between the AGI and AGF here.
Process A: Call trace: ? __schedule+0x2bd/0x620 schedule+0x33/0x90 schedule_timeout+0x17d/0x290 __down_common+0xef/0x125 ? xfs_buf_find+0x215/0x6c0 [xfs] down+0x3b/0x50 xfs_buf_lock+0x34/0xf0 [xfs] xfs_buf_find+0x215/0x6c0 [xfs] xfs_buf_get_map+0x37/0x230 [xfs] xfs_buf_read_map+0x29/0x190 [xfs] xfs_trans_read_buf_map+0x13d/0x520 [xfs] xfs_read_agf+0xa6/0x180 [xfs] ? schedule_timeout+0x17d/0x290 xfs_alloc_read_agf+0x52/0x1f0 [xfs] xfs_alloc_fix_freelist+0x432/0x590 [xfs] ? down+0x3b/0x50 ? xfs_buf_lock+0x34/0xf0 [xfs] ? xfs_buf_find+0x215/0x6c0 [xfs] xfs_alloc_vextent+0x301/0x6c0 [xfs] xfs_ialloc_ag_alloc+0x182/0x700 [xfs] ? _xfs_trans_bjoin+0x72/0xf0 [xfs] xfs_dialloc+0x116/0x290 [xfs] xfs_ialloc+0x6d/0x5e0 [xfs] ? xfs_log_reserve+0x165/0x280 [xfs] xfs_dir_ialloc+0x8c/0x240 [xfs] xfs_create+0x35a/0x610 [xfs] xfs_generic_create+0x1f1/0x2f0 [xfs] ...
Process B: Call trace: ? __schedule+0x2bd/0x620 ? xfs_bmapi_allocate+0x245/0x380 [xfs] schedule+0x33/0x90 schedule_timeout+0x17d/0x290 ? xfs_buf_find+0x1fd/0x6c0 [xfs] __down_common+0xef/0x125 ? xfs_buf_get_map+0x37/0x230 [xfs] ? xfs_buf_find+0x215/0x6c0 [xfs] down+0x3b/0x50 xfs_buf_lock+0x34/0xf0 [xfs] xfs_buf_find+0x215/0x6c0 [xfs] xfs_buf_get_map+0x37/0x230 [xfs] xfs_buf_read_map+0x29/0x190 [xfs] xfs_trans_read_buf_map+0x13d/0x520 [xfs] xfs_read_agi+0xa8/0x160 [xfs] xfs_iunlink_remove+0x6f/0x2a0 [xfs] ? current_time+0x46/0x80 ? xfs_trans_ichgtime+0x39/0xb0 [xfs] xfs_rename+0x57a/0xae0 [xfs] xfs_vn_rename+0xe4/0x150 [xfs] ...
In this patch we move the xfs_iunlink_remove() call to before acquiring the AGF lock to preserve correct AGI/AGF locking order.
Signed-off-by: kaixuxia kaixuxia@tencent.com Reviewed-by: Brian Foster bfoster@redhat.com Reviewed-by: Darrick J. Wong darrick.wong@oracle.com Signed-off-by: Darrick J. Wong darrick.wong@oracle.com
Minor massage required due to upstream change making xfs_bumplink() a void function where as in the 4.19.y tree the return value is checked, even though it is always zero. Only change was to the last code block removed by the patch. Functionally equivalent to upstream.
Signed-off-by: Suraj Jitindar Singh surajjs@amazon.com --- fs/xfs/xfs_inode.c | 85 +++++++++++++++++++++++----------------------- 1 file changed, 42 insertions(+), 43 deletions(-)
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index 5ed84d6c7059..f2d06e1e4906 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -2949,7 +2949,8 @@ xfs_rename( spaceres);
/* - * Set up the target. + * Check for expected errors before we dirty the transaction + * so we can return an error without a transaction abort. */ if (target_ip == NULL) { /* @@ -2961,6 +2962,46 @@ xfs_rename( if (error) goto out_trans_cancel; } + } else { + /* + * If target exists and it's a directory, check that whether + * it can be destroyed. + */ + if (S_ISDIR(VFS_I(target_ip)->i_mode) && + (!xfs_dir_isempty(target_ip) || + (VFS_I(target_ip)->i_nlink > 2))) { + error = -EEXIST; + goto out_trans_cancel; + } + } + + /* + * Directory entry creation below may acquire the AGF. Remove + * the whiteout from the unlinked list first to preserve correct + * AGI/AGF locking order. This dirties the transaction so failures + * after this point will abort and log recovery will clean up the + * mess. + * + * For whiteouts, we need to bump the link count on the whiteout + * inode. After this point, we have a real link, clear the tmpfile + * state flag from the inode so it doesn't accidentally get misused + * in future. + */ + if (wip) { + ASSERT(VFS_I(wip)->i_nlink == 0); + error = xfs_iunlink_remove(tp, wip); + if (error) + goto out_trans_cancel; + + xfs_bumplink(tp, wip); + xfs_trans_log_inode(tp, wip, XFS_ILOG_CORE); + VFS_I(wip)->i_state &= ~I_LINKABLE; + } + + /* + * Set up the target. + */ + if (target_ip == NULL) { /* * If target does not exist and the rename crosses * directories, adjust the target directory link count @@ -2980,22 +3021,6 @@ xfs_rename( goto out_trans_cancel; } } else { /* target_ip != NULL */ - /* - * If target exists and it's a directory, check that both - * target and source are directories and that target can be - * destroyed, or that neither is a directory. - */ - if (S_ISDIR(VFS_I(target_ip)->i_mode)) { - /* - * Make sure target dir is empty. - */ - if (!(xfs_dir_isempty(target_ip)) || - (VFS_I(target_ip)->i_nlink > 2)) { - error = -EEXIST; - goto out_trans_cancel; - } - } - /* * Link the source inode under the target name. * If the source inode is a directory and we are moving @@ -3086,32 +3111,6 @@ xfs_rename( if (error) goto out_trans_cancel;
- /* - * For whiteouts, we need to bump the link count on the whiteout inode. - * This means that failures all the way up to this point leave the inode - * on the unlinked list and so cleanup is a simple matter of dropping - * the remaining reference to it. If we fail here after bumping the link - * count, we're shutting down the filesystem so we'll never see the - * intermediate state on disk. - */ - if (wip) { - ASSERT(VFS_I(wip)->i_nlink == 0); - error = xfs_bumplink(tp, wip); - if (error) - goto out_trans_cancel; - error = xfs_iunlink_remove(tp, wip); - if (error) - goto out_trans_cancel; - xfs_trans_log_inode(tp, wip, XFS_ILOG_CORE); - - /* - * Now we have a real link, clear the "I'm a tmpfile" state - * flag from the inode so it doesn't accidentally get misused in - * future. - */ - VFS_I(wip)->i_state &= ~I_LINKABLE; - } - xfs_trans_ichgtime(tp, src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE); if (new_parent)
On Fri, Apr 24, 2020 at 04:05:30PM -0700, Suraj Jitindar Singh wrote:
This series backports two patches which fix known bugs in the xfs filesystem code to the v4.14.y stable tree.
They are each verified by the xfs tests xfs/439 and generic/585 respectively.
The first patch applies cleanly.
The second patch required slight massage due to the last code block being removed having changed slightly upstream due to rework. I think the backport is functionally equivalent. Only thing is I request comment that it is correct to use the following error path:
ASSERT(VFS_I(wip)->i_nlink == 0); error = xfs_iunlink_remove(tp, wip); if (error)
goto out_trans_cancel;The old error patch out_bmap_cancel still exists here. However as nothing can have modified the deferred ops struct at this point I believe it is sufficient to go to the "out_trans_cancel" error label.
Darrick J. Wong (1): xfs: validate sb_logsunit is a multiple of the fs blocksize
kaixuxia (1): xfs: Fix deadlock between AGI and AGF with RENAME_WHITEOUT
fs/xfs/xfs_inode.c | 85 +++++++++++++++++++++++----------------------- fs/xfs/xfs_log.c | 14 +++++++- 2 files changed, 55 insertions(+), 44 deletions(-)
All (including the 4.19 patch), now queued up, thanks.
greg k-h
linux-stable-mirror@lists.linaro.org
-
Greg KH -
Sasha Levin -
Suraj Jitindar Singh