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* btrfs: fix use after free iterating extrefsChris Mason2015-10-141-5/+3
| | | | | | | | | | | | | | | | | | | The code for btrfs inode-resolve has never worked properly for files with enough hard links to trigger extrefs. It was trying to get the leaf out of a path after freeing the path: btrfs_release_path(path); leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, slot); The fix here is to use the extent buffer we cloned just a little higher up to avoid deadlocks caused by using the leaf in the path. Signed-off-by: Chris Mason <clm@fb.com> cc: stable@vger.kernel.org # v3.7+ cc: Mark Fasheh <mfasheh@suse.de> Reviewed-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de>
* btrfs: check unsupported filters in balance argumentsDavid Sterba2015-10-142-0/+13
| | | | | | | | | | | | | | We don't verify that all the balance filter arguments supplemented by the flags are actually known to the kernel. Thus we let it silently pass and do nothing. At the moment this means only the 'limit' filter, but we're going to add a few more soon so it's better to have that fixed. Also in older stable kernels so that it works with newer userspace tools. Cc: stable@vger.kernel.org # 3.16+ Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* BTRFS: support NFSv2 exportNeilBrown2015-10-061-5/+5
| | | | | | | | | | | | | | The "fh_len" passed to ->fh_to_* is not guaranteed to be that same as that returned by encode_fh - it may be larger. With NFSv2, the filehandle is fixed length, so it may appear longer than expected and be zero-padded. So we must test that fh_len is at least some value, not exactly equal to it. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: David Sterba <dsterba@suse.cz>
* Btrfs: open_ctree: Fix possible memory leakchandan2015-10-061-0/+4
| | | | | | | | After reading one of chunk or tree root tree's root node from disk, if the root node does not have EXTENT_BUFFER_UPTODATE flag set, we fail to release the memory used by the root node. Fix this. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
* Btrfs: fix deadlock when finalizing block group creationFilipe Manana2015-10-063-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Josef ran into a deadlock while a transaction handle was finalizing the creation of its block groups, which produced the following trace: [260445.593112] fio D ffff88022a9df468 0 8924 4518 0x00000084 [260445.593119] ffff88022a9df468 ffffffff81c134c0 ffff880429693c00 ffff88022a9df488 [260445.593126] ffff88022a9e0000 ffff8803490d7b00 ffff8803490d7b18 ffff88022a9df4b0 [260445.593132] ffff8803490d7af8 ffff88022a9df488 ffffffff8175a437 ffff8803490d7b00 [260445.593137] Call Trace: [260445.593145] [<ffffffff8175a437>] schedule+0x37/0x80 [260445.593189] [<ffffffffa0850f37>] btrfs_tree_lock+0xa7/0x1f0 [btrfs] [260445.593197] [<ffffffff810db7c0>] ? prepare_to_wait_event+0xf0/0xf0 [260445.593225] [<ffffffffa07eac44>] btrfs_lock_root_node+0x34/0x50 [btrfs] [260445.593253] [<ffffffffa07eff6b>] btrfs_search_slot+0x88b/0xa00 [btrfs] [260445.593295] [<ffffffffa08389df>] ? free_extent_buffer+0x4f/0x90 [btrfs] [260445.593324] [<ffffffffa07f1a06>] btrfs_insert_empty_items+0x66/0xc0 [btrfs] [260445.593351] [<ffffffffa07ea94a>] ? btrfs_alloc_path+0x1a/0x20 [btrfs] [260445.593394] [<ffffffffa08403b9>] btrfs_finish_chunk_alloc+0x1c9/0x570 [btrfs] [260445.593427] [<ffffffffa08002ab>] btrfs_create_pending_block_groups+0x11b/0x200 [btrfs] [260445.593459] [<ffffffffa0800964>] do_chunk_alloc+0x2a4/0x2e0 [btrfs] [260445.593491] [<ffffffffa0803815>] find_free_extent+0xa55/0xd90 [btrfs] [260445.593524] [<ffffffffa0803c22>] btrfs_reserve_extent+0xd2/0x220 [btrfs] [260445.593532] [<ffffffff8119fe5d>] ? account_page_dirtied+0xdd/0x170 [260445.593564] [<ffffffffa0803e78>] btrfs_alloc_tree_block+0x108/0x4a0 [btrfs] [260445.593597] [<ffffffffa080c9de>] ? btree_set_page_dirty+0xe/0x10 [btrfs] [260445.593626] [<ffffffffa07eb5cd>] __btrfs_cow_block+0x12d/0x5b0 [btrfs] [260445.593654] [<ffffffffa07ebbff>] btrfs_cow_block+0x11f/0x1c0 [btrfs] [260445.593682] [<ffffffffa07ef8c7>] btrfs_search_slot+0x1e7/0xa00 [btrfs] [260445.593724] [<ffffffffa08389df>] ? free_extent_buffer+0x4f/0x90 [btrfs] [260445.593752] [<ffffffffa07f1a06>] btrfs_insert_empty_items+0x66/0xc0 [btrfs] [260445.593830] [<ffffffffa07ea94a>] ? btrfs_alloc_path+0x1a/0x20 [btrfs] [260445.593905] [<ffffffffa08403b9>] btrfs_finish_chunk_alloc+0x1c9/0x570 [btrfs] [260445.593946] [<ffffffffa08002ab>] btrfs_create_pending_block_groups+0x11b/0x200 [btrfs] [260445.593990] [<ffffffffa0815798>] btrfs_commit_transaction+0xa8/0xb40 [btrfs] [260445.594042] [<ffffffffa085abcd>] ? btrfs_log_dentry_safe+0x6d/0x80 [btrfs] [260445.594089] [<ffffffffa082bc84>] btrfs_sync_file+0x294/0x350 [btrfs] [260445.594115] [<ffffffff8123e29b>] vfs_fsync_range+0x3b/0xa0 [260445.594133] [<ffffffff81023891>] ? syscall_trace_enter_phase1+0x131/0x180 [260445.594149] [<ffffffff8123e35d>] do_fsync+0x3d/0x70 [260445.594169] [<ffffffff81023bb8>] ? syscall_trace_leave+0xb8/0x110 [260445.594187] [<ffffffff8123e600>] SyS_fsync+0x10/0x20 [260445.594204] [<ffffffff8175de6e>] entry_SYSCALL_64_fastpath+0x12/0x71 This happened because the same transaction handle created a large number of block groups and while finalizing their creation (inserting new items and updating existing items in the chunk and device trees) a new metadata extent had to be allocated and no free space was found in the current metadata block groups, which made find_free_extent() attempt to allocate a new block group via do_chunk_alloc(). However at do_chunk_alloc() we ended up allocating a new system chunk too and exceeded the threshold of 2Mb of reserved chunk bytes, which makes do_chunk_alloc() enter the final part of block group creation again (at btrfs_create_pending_block_groups()) and attempt to lock again the root of the chunk tree when it's already write locked by the same task. Similarly we can deadlock on extent tree nodes/leafs if while we are running delayed references we end up creating a new metadata block group in order to allocate a new node/leaf for the extent tree (as part of a CoW operation or growing the tree), as btrfs_create_pending_block_groups inserts items into the extent tree as well. In this case we get the following trace: [14242.773581] fio D ffff880428ca3418 0 3615 3100 0x00000084 [14242.773588] ffff880428ca3418 ffff88042d66b000 ffff88042a03c800 ffff880428ca3438 [14242.773594] ffff880428ca4000 ffff8803e4b20190 ffff8803e4b201a8 ffff880428ca3460 [14242.773600] ffff8803e4b20188 ffff880428ca3438 ffffffff8175a437 ffff8803e4b20190 [14242.773606] Call Trace: [14242.773613] [<ffffffff8175a437>] schedule+0x37/0x80 [14242.773656] [<ffffffffa057ff07>] btrfs_tree_lock+0xa7/0x1f0 [btrfs] [14242.773664] [<ffffffff810db7c0>] ? prepare_to_wait_event+0xf0/0xf0 [14242.773692] [<ffffffffa0519c44>] btrfs_lock_root_node+0x34/0x50 [btrfs] [14242.773720] [<ffffffffa051ef6b>] btrfs_search_slot+0x88b/0xa00 [btrfs] [14242.773750] [<ffffffffa0520a06>] btrfs_insert_empty_items+0x66/0xc0 [btrfs] [14242.773758] [<ffffffff811ef4a2>] ? kmem_cache_alloc+0x1d2/0x200 [14242.773786] [<ffffffffa0520ad1>] btrfs_insert_item+0x71/0xf0 [btrfs] [14242.773818] [<ffffffffa052f292>] btrfs_create_pending_block_groups+0x102/0x200 [btrfs] [14242.773850] [<ffffffffa052f96e>] do_chunk_alloc+0x2ae/0x2f0 [btrfs] [14242.773934] [<ffffffffa0532825>] find_free_extent+0xa55/0xd90 [btrfs] [14242.773998] [<ffffffffa0532c22>] btrfs_reserve_extent+0xc2/0x1d0 [btrfs] [14242.774041] [<ffffffffa0532e38>] btrfs_alloc_tree_block+0x108/0x4a0 [btrfs] [14242.774078] [<ffffffffa051a5cd>] __btrfs_cow_block+0x12d/0x5b0 [btrfs] [14242.774118] [<ffffffffa051abff>] btrfs_cow_block+0x11f/0x1c0 [btrfs] [14242.774155] [<ffffffffa051e8c7>] btrfs_search_slot+0x1e7/0xa00 [btrfs] [14242.774194] [<ffffffffa0528021>] ? __btrfs_free_extent.isra.70+0x2e1/0xcb0 [btrfs] [14242.774235] [<ffffffffa0520a06>] btrfs_insert_empty_items+0x66/0xc0 [btrfs] [14242.774274] [<ffffffffa051994a>] ? btrfs_alloc_path+0x1a/0x20 [btrfs] [14242.774318] [<ffffffffa052c433>] __btrfs_run_delayed_refs+0xbb3/0x1020 [btrfs] [14242.774358] [<ffffffffa052f404>] btrfs_run_delayed_refs.part.78+0x74/0x280 [btrfs] [14242.774391] [<ffffffffa052f627>] btrfs_run_delayed_refs+0x17/0x20 [btrfs] [14242.774432] [<ffffffffa05be236>] commit_cowonly_roots+0x8d/0x2bd [btrfs] [14242.774474] [<ffffffffa059d07f>] ? __btrfs_run_delayed_items+0x1cf/0x210 [btrfs] [14242.774516] [<ffffffffa05adac3>] ? btrfs_qgroup_account_extents+0x83/0x130 [btrfs] [14242.774558] [<ffffffffa0544c40>] btrfs_commit_transaction+0x590/0xb40 [btrfs] [14242.774599] [<ffffffffa0589b9d>] ? btrfs_log_dentry_safe+0x6d/0x80 [btrfs] [14242.774642] [<ffffffffa055ac54>] btrfs_sync_file+0x294/0x350 [btrfs] [14242.774650] [<ffffffff8123e29b>] vfs_fsync_range+0x3b/0xa0 [14242.774657] [<ffffffff81023891>] ? syscall_trace_enter_phase1+0x131/0x180 [14242.774663] [<ffffffff8123e35d>] do_fsync+0x3d/0x70 [14242.774669] [<ffffffff81023bb8>] ? syscall_trace_leave+0xb8/0x110 [14242.774675] [<ffffffff8123e600>] SyS_fsync+0x10/0x20 [14242.774681] [<ffffffff8175de6e>] entry_SYSCALL_64_fastpath+0x12/0x71 Fix this by never recursing into the finalization phase of block group creation and making sure we never trigger the finalization of block group creation while running delayed references. Reported-by: Josef Bacik <jbacik@fb.com> Fixes: 00d80e342c0f ("Btrfs: fix quick exhaustion of the system array in the superblock") Signed-off-by: Filipe Manana <fdmanana@suse.com>
* Btrfs: update fix for read corruption of compressed and shared extentsFilipe Manana2015-10-061-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | My previous fix in commit 005efedf2c7d ("Btrfs: fix read corruption of compressed and shared extents") was effective only if the compressed extents cover a file range with a length that is not a multiple of 16 pages. That's because the detection of when we reached a different range of the file that shares the same compressed extent as the previously processed range was done at extent_io.c:__do_contiguous_readpages(), which covers subranges with a length up to 16 pages, because extent_readpages() groups the pages in clusters no larger than 16 pages. So fix this by tracking the start of the previously processed file range's extent map at extent_readpages(). The following test case for fstests reproduces the issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter # real QA test starts here _need_to_be_root _supported_fs btrfs _supported_os Linux _require_scratch _require_cloner rm -f $seqres.full test_clone_and_read_compressed_extent() { local mount_opts=$1 _scratch_mkfs >>$seqres.full 2>&1 _scratch_mount $mount_opts # Create our test file with a single extent of 64Kb that is going to # be compressed no matter which compression algo is used (zlib/lzo). $XFS_IO_PROG -f -c "pwrite -S 0xaa 0K 64K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now clone the compressed extent into an adjacent file offset. $CLONER_PROG -s 0 -d $((64 * 1024)) -l $((64 * 1024)) \ $SCRATCH_MNT/foo $SCRATCH_MNT/foo echo "File digest before unmount:" md5sum $SCRATCH_MNT/foo | _filter_scratch # Remount the fs or clear the page cache to trigger the bug in # btrfs. Because the extent has an uncompressed length that is a # multiple of 16 pages, all the pages belonging to the second range # of the file (64K to 128K), which points to the same extent as the # first range (0K to 64K), had their contents full of zeroes instead # of the byte 0xaa. This was a bug exclusively in the read path of # compressed extents, the correct data was stored on disk, btrfs # just failed to fill in the pages correctly. _scratch_remount echo "File digest after remount:" # Must match the digest we got before. md5sum $SCRATCH_MNT/foo | _filter_scratch } echo -e "\nTesting with zlib compression..." test_clone_and_read_compressed_extent "-o compress=zlib" _scratch_unmount echo -e "\nTesting with lzo compression..." test_clone_and_read_compressed_extent "-o compress=lzo" status=0 exit Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Tested-by: Timofey Titovets <nefelim4ag@gmail.com>
* Btrfs: send, fix corner case for reference overwrite detectionFilipe Manana2015-10-061-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the inode given to did_overwrite_ref() matches the current progress and has a reference that collides with the reference of other inode that has the same number as the current progress, we were always telling our caller that the inode's reference was overwritten, which is incorrect because the other inode might be a new inode (different generation number) in which case we must return false from did_overwrite_ref() so that its callers don't use an orphanized path for the inode (as it will never be orphanized, instead it will be unlinked and the new inode created later). The following test case for fstests reproduces the issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { rm -fr $send_files_dir rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter # real QA test starts here _supported_fs btrfs _supported_os Linux _require_scratch _need_to_be_root send_files_dir=$TEST_DIR/btrfs-test-$seq rm -f $seqres.full rm -fr $send_files_dir mkdir $send_files_dir _scratch_mkfs >>$seqres.full 2>&1 _scratch_mount # Create our test file with a single extent of 64K. mkdir -p $SCRATCH_MNT/foo $XFS_IO_PROG -f -c "pwrite -S 0xaa 0 64K" $SCRATCH_MNT/foo/bar \ | _filter_xfs_io _run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT \ $SCRATCH_MNT/mysnap1 _run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT \ $SCRATCH_MNT/mysnap2 echo "File digest before being replaced:" md5sum $SCRATCH_MNT/mysnap1/foo/bar | _filter_scratch # Remove the file and then create a new one in the same location with # the same name but with different content. This new file ends up # getting the same inode number as the previous one, because that inode # number was the highest inode number used by the snapshot's root and # therefore when attempting to find the a new inode number for the new # file, we end up reusing the same inode number. This happens because # currently btrfs uses the highest inode number summed by 1 for the # first inode created once a snapshot's root is loaded (done at # fs/btrfs/inode-map.c:btrfs_find_free_objectid in the linux kernel # tree). # Having these two different files in the snapshots with the same inode # number (but different generation numbers) caused the btrfs send code # to emit an incorrect path for the file when issuing an unlink # operation because it failed to realize they were different files. rm -f $SCRATCH_MNT/mysnap2/foo/bar $XFS_IO_PROG -f -c "pwrite -S 0xbb 0 96K" \ $SCRATCH_MNT/mysnap2/foo/bar | _filter_xfs_io _run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT/mysnap2 \ $SCRATCH_MNT/mysnap2_ro _run_btrfs_util_prog send $SCRATCH_MNT/mysnap1 -f $send_files_dir/1.snap _run_btrfs_util_prog send -p $SCRATCH_MNT/mysnap1 \ $SCRATCH_MNT/mysnap2_ro -f $send_files_dir/2.snap echo "File digest in the original filesystem after being replaced:" md5sum $SCRATCH_MNT/mysnap2_ro/foo/bar | _filter_scratch # Now recreate the filesystem by receiving both send streams and verify # we get the same file contents that the original filesystem had. _scratch_unmount _scratch_mkfs >>$seqres.full 2>&1 _scratch_mount _run_btrfs_util_prog receive -vv $SCRATCH_MNT -f $send_files_dir/1.snap _run_btrfs_util_prog receive -vv $SCRATCH_MNT -f $send_files_dir/2.snap echo "File digest in the new filesystem:" # Must match the digest from the new file. md5sum $SCRATCH_MNT/mysnap2_ro/foo/bar | _filter_scratch status=0 exit Reported-by: Martin Raiber <martin@urbackup.org> Fixes: 8b191a684968 ("Btrfs: incremental send, check if orphanized dir inode needs delayed rename") Signed-off-by: Filipe Manana <fdmanana@suse.com>
* Btrfs: keep dropped roots in cache until transaction commitJosef Bacik2015-09-223-2/+37
| | | | | | | | | | | | | | | | | When dropping a snapshot we need to account for the qgroup changes. If we drop the snapshot in all one go then the backref code will fail to find blocks from the snapshot we dropped since it won't be able to find the root in the fs root cache. This can lead to us failing to find refs from other roots that pointed at blocks in the now deleted root. To handle this we need to not remove the fs roots from the cache until after we process the qgroup operations. Do this by adding dropped roots to a list on the transaction, and letting the transaction remove the roots at the same time it drops the commit roots. This will keep all of the backref searching code in sync properly, and fixes a problem Mark was seeing with snapshot delete and qgroups. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Tested-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: Direct I/O: Fix space accountingchandan2015-09-212-23/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following call trace is seen when generic/095 test is executed, WARNING: CPU: 3 PID: 2769 at /home/chandan/code/repos/linux/fs/btrfs/inode.c:8967 btrfs_destroy_inode+0x284/0x2a0() Modules linked in: CPU: 3 PID: 2769 Comm: umount Not tainted 4.2.0-rc5+ #31 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20150306_163512-brownie 04/01/2014 ffffffff81c08150 ffff8802ec9cbce8 ffffffff81984058 ffff8802ffd8feb0 0000000000000000 ffff8802ec9cbd28 ffffffff81050385 ffff8802ec9cbd38 ffff8802d12f8588 ffff8802d12f8588 ffff8802f15ab000 ffff8800bb96c0b0 Call Trace: [<ffffffff81984058>] dump_stack+0x45/0x57 [<ffffffff81050385>] warn_slowpath_common+0x85/0xc0 [<ffffffff81050465>] warn_slowpath_null+0x15/0x20 [<ffffffff81340294>] btrfs_destroy_inode+0x284/0x2a0 [<ffffffff8117ce07>] destroy_inode+0x37/0x60 [<ffffffff8117cf39>] evict+0x109/0x170 [<ffffffff8117cfd5>] dispose_list+0x35/0x50 [<ffffffff8117dd3a>] evict_inodes+0xaa/0x100 [<ffffffff81165667>] generic_shutdown_super+0x47/0xf0 [<ffffffff81165951>] kill_anon_super+0x11/0x20 [<ffffffff81302093>] btrfs_kill_super+0x13/0x110 [<ffffffff81165c99>] deactivate_locked_super+0x39/0x70 [<ffffffff811660cf>] deactivate_super+0x5f/0x70 [<ffffffff81180e1e>] cleanup_mnt+0x3e/0x90 [<ffffffff81180ebd>] __cleanup_mnt+0xd/0x10 [<ffffffff81069c06>] task_work_run+0x96/0xb0 [<ffffffff81003a3d>] do_notify_resume+0x3d/0x50 [<ffffffff8198cbc2>] int_signal+0x12/0x17 This means that the inode had non-zero "outstanding extents" during eviction. This occurs because, during direct I/O a task which successfully used up its reserved data space would set BTRFS_INODE_DIO_READY bit and does not clear the bit after finishing the DIO write. A future DIO write could actually fail and the unused reserve space won't be freed because of the previously set BTRFS_INODE_DIO_READY bit. Clearing the BTRFS_INODE_DIO_READY bit in btrfs_direct_IO() caused the following issue, |-----------------------------------+-------------------------------------| | Task A | Task B | |-----------------------------------+-------------------------------------| | Start direct i/o write on inode X.| | | reserve space | | | Allocate ordered extent | | | release reserved space | | | Set BTRFS_INODE_DIO_READY bit. | | | | splice() | | | Transfer data from pipe buffer to | | | destination file. | | | - kmap(pipe buffer page) | | | - Start direct i/o write on | | | inode X. | | | - reserve space | | | - dio_refill_pages() | | | - sdio->blocks_available == 0 | | | - Since a kernel address is | | | being passed instead of a | | | user space address, | | | iov_iter_get_pages() returns | | | -EFAULT. | | | - Since BTRFS_INODE_DIO_READY is | | | set, we don't release reserved | | | space. | | | - Clear BTRFS_INODE_DIO_READY bit.| | -EIOCBQUEUED is returned. | | |-----------------------------------+-------------------------------------| Hence this commit introduces "struct btrfs_dio_data" to track the usage of reserved data space. The remaining unused "reserve space" can now be freed reliably. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: skip waiting on ordered range for special filesJeff Mahoney2015-09-151-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | In btrfs_evict_inode, we properly truncate the page cache for evicted inodes but then we call btrfs_wait_ordered_range for every inode as well. It's the right thing to do for regular files but results in incorrect behavior for device inodes for block devices. filemap_fdatawrite_range gets called with inode->i_mapping which gets resolved to the block device inode before getting passed to wbc_attach_fdatawrite_inode and ultimately to inode_to_bdi. What happens next depends on whether there's an open file handle associated with the inode. If there is, we write to the block device, which is unexpected behavior. If there isn't, we through normally and inode->i_data is used. We can also end up racing against open/close which can result in crashes when i_mapping points to a block device inode that has been closed. Since there can't be any page cache associated with special file inodes, it's safe to skip the btrfs_wait_ordered_range call entirely and avoid the problem. Cc: <stable@vger.kernel.org> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=100911 Tested-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de> Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com>
* Btrfs: fix read corruption of compressed and shared extentsFilipe Manana2015-09-151-8/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a file has a range pointing to a compressed extent, followed by another range that points to the same compressed extent and a read operation attempts to read both ranges (either completely or part of them), the pages that correspond to the second range are incorrectly filled with zeroes. Consider the following example: File layout [0 - 8K] [8K - 24K] | | | | points to extent X, points to extent X, offset 4K, length of 8K offset 0, length 16K [extent X, compressed length = 4K uncompressed length = 16K] If a readpages() call spans the 2 ranges, a single bio to read the extent is submitted - extent_io.c:submit_extent_page() would only create a new bio to cover the second range pointing to the extent if the extent it points to had a different logical address than the extent associated with the first range. This has a consequence of the compressed read end io handler (compression.c:end_compressed_bio_read()) finish once the extent is decompressed into the pages covering the first range, leaving the remaining pages (belonging to the second range) filled with zeroes (done by compression.c:btrfs_clear_biovec_end()). So fix this by submitting the current bio whenever we find a range pointing to a compressed extent that was preceded by a range with a different extent map. This is the simplest solution for this corner case. Making the end io callback populate both ranges (or more, if we have multiple pointing to the same extent) is a much more complex solution since each bio is tightly coupled with a single extent map and the extent maps associated to the ranges pointing to the shared extent can have different offsets and lengths. The following test case for fstests triggers the issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter # real QA test starts here _need_to_be_root _supported_fs btrfs _supported_os Linux _require_scratch _require_cloner rm -f $seqres.full test_clone_and_read_compressed_extent() { local mount_opts=$1 _scratch_mkfs >>$seqres.full 2>&1 _scratch_mount $mount_opts # Create a test file with a single extent that is compressed (the # data we write into it is highly compressible no matter which # compression algorithm is used, zlib or lzo). $XFS_IO_PROG -f -c "pwrite -S 0xaa 0K 4K" \ -c "pwrite -S 0xbb 4K 8K" \ -c "pwrite -S 0xcc 12K 4K" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now clone our extent into an adjacent offset. $CLONER_PROG -s $((4 * 1024)) -d $((16 * 1024)) -l $((8 * 1024)) \ $SCRATCH_MNT/foo $SCRATCH_MNT/foo # Same as before but for this file we clone the extent into a lower # file offset. $XFS_IO_PROG -f -c "pwrite -S 0xaa 8K 4K" \ -c "pwrite -S 0xbb 12K 8K" \ -c "pwrite -S 0xcc 20K 4K" \ $SCRATCH_MNT/bar | _filter_xfs_io $CLONER_PROG -s $((12 * 1024)) -d 0 -l $((8 * 1024)) \ $SCRATCH_MNT/bar $SCRATCH_MNT/bar echo "File digests before unmounting filesystem:" md5sum $SCRATCH_MNT/foo | _filter_scratch md5sum $SCRATCH_MNT/bar | _filter_scratch # Evicting the inode or clearing the page cache before reading # again the file would also trigger the bug - reads were returning # all bytes in the range corresponding to the second reference to # the extent with a value of 0, but the correct data was persisted # (it was a bug exclusively in the read path). The issue happened # only if the same readpages() call targeted pages belonging to the # first and second ranges that point to the same compressed extent. _scratch_remount echo "File digests after mounting filesystem again:" # Must match the same digests we got before. md5sum $SCRATCH_MNT/foo | _filter_scratch md5sum $SCRATCH_MNT/bar | _filter_scratch } echo -e "\nTesting with zlib compression..." test_clone_and_read_compressed_extent "-o compress=zlib" _scratch_unmount echo -e "\nTesting with lzo compression..." test_clone_and_read_compressed_extent "-o compress=lzo" status=0 exit Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Qu Wenruo<quwenruo@cn.fujitsu.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
* Btrfs: remove unnecessary locking of cleaner_mutex to avoid deadlockFilipe Manana2015-09-102-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After commmit e44163e17796 ("btrfs: explictly delete unused block groups in close_ctree and ro-remount"), added in the 4.3 merge window, we have calls to btrfs_delete_unused_bgs() while holding the cleaner_mutex. This can cause a deadlock with a concurrent block group relocation (when a filesystem balance or shrink operation is in progress for example) because btrfs_delete_unused_bgs() locks delete_unused_bgs_mutex and the relocation path locks first delete_unused_bgs_mutex and then it locks cleaner_mutex, resulting in a classic ABBA deadlock: CPU 0 CPU 1 lock fs_info->cleaner_mutex __btrfs_balance() || btrfs_shrink_device() lock fs_info->delete_unused_bgs_mutex btrfs_relocate_chunk() btrfs_relocate_block_group() lock fs_info->cleaner_mutex btrfs_delete_unused_bgs() lock fs_info->delete_unused_bgs_mutex Fix this by not taking the cleaner_mutex before calling btrfs_delete_unused_bgs() because it's no longer needed after commit 67c5e7d464bc ("Btrfs: fix race between balance and unused block group deletion"). The mutex fs_info->delete_unused_bgs_mutex, the spinlock fs_info->unused_bgs_lock and a block group's spinlock are enough to get correct serialization between tasks running relocation and unused block group deletion (as well as between multiple tasks concurrently calling btrfs_delete_unused_bgs()). This issue was discussed (in the mailing list) during the review of the patch titled "btrfs: explictly delete unused block groups in close_ctree and ro-remount" and it was agreed that acquiring the cleaner mutex had to be dropped after the patch titled "Btrfs: fix race between balance and unused block group deletion" got merged (both patches were submitted at about the same time, but one landed in kernel 4.2 and the other in the 4.3 merge window). Signed-off-by: Filipe Manana <fdmanana@suse.com>
* Btrfs: don't initialize a space info as full to prevent ENOSPCFilipe Manana2015-09-081-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 2e6e518335f8 ("Btrfs: fix block group ->space_info null pointer dereference") accidently marked a space info as full when initializing it with a value of 0 total bytes. This introduces an ENOSPC problem when writing file data if we mount a filesystem that has no data block groups allocated, because the data space info is initialized with 0 total bytes, marked as full, and it never gets its total bytes incremented by a (positive) value to unmark it as full (because there are no data block groups loaded when the fs is mounted). For metadata and system spaces this issue can never happen since we always have at least one metadata block group and one system block group (even for an empty filesystem). So fix this by just not initializing a space info as full, reverting the offending part of the commit mentioned above. The following test case for fstests reproduces the issue: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter # real QA test starts here _need_to_be_root _supported_fs btrfs _supported_os Linux _require_scratch rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 # Mount our filesystem without space caches enabled so that we do not # get any space used from the initial data block group that mkfs creates # (space caches used space from data block groups). _scratch_mount "-o nospace_cache" # Need an fs with at least 2Gb to make sure mkfs.btrfs does not create # an fs using mixed block groups (used both for data and metadata). We # really need to have dedicated block groups for data to reproduce the # issue and mkfs.btrfs defaults to mixed block groups only for small # filesystems (up to 1Gb). _require_fs_space $SCRATCH_MNT $((2 * 1024 * 1024)) # Run balance with the purpose of deleting the unused data block group # that mkfs created. We could also wait for the background kthread to # automatically delete the unused block group, but we do not have a way # to make it run and wait for it to complete, so just do a balance # instead of some unreliable sleep _run_btrfs_util_prog balance start -dusage=0 $SCRATCH_MNT # Now unmount the filesystem, mount it again (either with or with space # caches enabled, it does not matter to trigger the problem) and attempt # to create a file with some data - this used to fail with ENOSPC # because there were no data block groups when the filesystem was # mounted and the data space info object was marked as full when # initialized (because it had 0 total bytes), which prevented the file # write path from attempting to allocate a data block group and fail # immediately with ENOSPC. _scratch_remount echo "hello world" > $SCRATCH_MNT/foobar echo "Silence is golden" status=0 exit Signed-off-by: Filipe Manana <fdmanana@suse.com>
* Btrfs: cleanup: remove unnecessary check before btrfs_free_path is calledTsutomu Itoh2015-08-313-6/+3
| | | | | | | | | We need not check path before btrfs_free_path() is called because path is checked in btrfs_free_path(). Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: async_thread: Fix workqueue 'max_active' value when initializingQu Wenruo2015-08-312-24/+35
| | | | | | | | | | | | | | | | | | At initializing time, for threshold-able workqueue, it's max_active of kernel workqueue should be 1 and grow if it hits threshold. But due to the bad naming, there is both 'max_active' for kernel workqueue and btrfs workqueue. So wrong value is given at workqueue initialization. This patch fixes it, and to avoid further misunderstanding, change the member name of btrfs_workqueue to 'current_active' and 'limit_active'. Also corresponding comment is added for readability. Reported-by: Alex Lyakas <alex.btrfs@zadarastorage.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: Add raid56 support for updatingZhao Lei2015-08-313-39/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | num_tolerated_disk_barrier_failures in btrfs_balance Code for updating fs_info->num_tolerated_disk_barrier_failures in btrfs_balance() lacks raid56 support. Reason: Above code was wroten in 2012-08-01, together with btrfs_calc_num_tolerated_disk_barrier_failures()'s first version. Then, btrfs_calc_num_tolerated_disk_barrier_failures() got updated later to support raid56, but code in btrfs_balance() was not updated together. Fix: Merge above similar code to a common function: btrfs_get_num_tolerated_disk_barrier_failures() and make it support both case. It can fix this bug with a bonus of cleanup, and make these code never in above no-sync state from now on. Suggested-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: Cleanup for btrfs_calc_num_tolerated_disk_barrier_failuresZhao Lei2015-08-311-40/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1: Use ARRAY_SIZE(types) to replace a static-value variant: int num_types = 4; 2: Use 'continue' on condition to reduce one level tab if (!XXX) { code; ... } -> if (XXX) continue; code; ... 3: Put setting 'num_tolerated_disk_barrier_failures = 2' to (num_tolerated_disk_barrier_failures > 2) condition to make make logic neat. if (num_tolerated_disk_barrier_failures > 0 && XXX) num_tolerated_disk_barrier_failures = 0; else if (num_tolerated_disk_barrier_failures > 1) { if (XXX) num_tolerated_disk_barrier_failures = 1; else if (XXX) num_tolerated_disk_barrier_failures = 2; -> if (num_tolerated_disk_barrier_failures > 0 && XXX) num_tolerated_disk_barrier_failures = 0; if (num_tolerated_disk_barrier_failures > 1 && XXX) num_tolerated_disk_barrier_failures = ; if (num_tolerated_disk_barrier_failures > 2 && XXX) num_tolerated_disk_barrier_failures = 2; 4: Remove comment of: num_mirrors - 1: if RAID1 or RAID10 is configured and more than 2 mirrors are used. which is not fit with code. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: Remove noused chunk_tree and chunk_objectid from ↵Zhao Lei2015-08-311-8/+2
| | | | | | | | | scrub_enumerate_chunks and scrub_chunk These variables are not used from introduced version, remove them. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: Update out-of-date "skip parity stripe" commentZhao Lei2015-08-311-1/+1
| | | | | | | Because btrfs support scrub raid56 parity stripe now. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: fix compile when block cgroups are not enabledChris Mason2015-08-212-0/+5
| | | | | | | | | | | bio->bi_css and bio->bi_ioc don't exist when block cgroups are not on. This adds an ifdef around them. It's not perfect, but our use of bi_ioc is being removed in the 4.3 merge window. The bi_css usage really should go into bio_clone, but I want to make sure that doesn't introduce problems for other bio_clone use cases. Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: fix file read corruption after extent cloning and fsyncFilipe Manana2015-08-191-0/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we partially clone one extent of a file into a lower offset of the file, fsync the file, power fail and then mount the fs to trigger log replay, we can get multiple checksum items in the csum tree that overlap each other and result in checksum lookup failures later. Those failures can make file data read requests assume a checksum value of 0, but they will not return an error (-EIO for example) to userspace exactly because the expected checksum value 0 is a special value that makes the read bio endio callback return success and set all the bytes of the corresponding page with the value 0x01 (at fs/btrfs/inode.c:__readpage_endio_check()). From a userspace perspective this is equivalent to file corruption because we are not returning what was written to the file. Details about how this can happen, and why, are included inline in the following reproducer test case for fstests and the comment added to tree-log.c. seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { _cleanup_flakey rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter . ./common/dmflakey # real QA test starts here _need_to_be_root _supported_fs btrfs _supported_os Linux _require_scratch _require_dm_flakey _require_cloner _require_metadata_journaling $SCRATCH_DEV rm -f $seqres.full _scratch_mkfs >>$seqres.full 2>&1 _init_flakey _mount_flakey # Create our test file with a single 100K extent starting at file # offset 800K. We fsync the file here to make the fsync log tree gets # a single csum item that covers the whole 100K extent, which causes # the second fsync, done after the cloning operation below, to not # leave in the log tree two csum items covering two sub-ranges # ([0, 20K[ and [20K, 100K[)) of our extent. $XFS_IO_PROG -f -c "pwrite -S 0xaa 800K 100K" \ -c "fsync" \ $SCRATCH_MNT/foo | _filter_xfs_io # Now clone part of our extent into file offset 400K. This adds a file # extent item to our inode's metadata that points to the 100K extent # we created before, using a data offset of 20K and a data length of # 20K, so that it refers to the sub-range [20K, 40K[ of our original # extent. $CLONER_PROG -s $((800 * 1024 + 20 * 1024)) -d $((400 * 1024)) \ -l $((20 * 1024)) $SCRATCH_MNT/foo $SCRATCH_MNT/foo # Now fsync our file to make sure the extent cloning is durably # persisted. This fsync will not add a second csum item to the log # tree containing the checksums for the blocks in the sub-range # [20K, 40K[ of our extent, because there was already a csum item in # the log tree covering the whole extent, added by the first fsync # we did before. $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo echo "File digest before power failure:" md5sum $SCRATCH_MNT/foo | _filter_scratch # Silently drop all writes and ummount to simulate a crash/power # failure. _load_flakey_table $FLAKEY_DROP_WRITES _unmount_flakey # Allow writes again, mount to trigger log replay and validate file # contents. # The fsync log replay first processes the file extent item # corresponding to the file offset 400K (the one which refers to the # [20K, 40K[ sub-range of our 100K extent) and then processes the file # extent item for file offset 800K. It used to happen that when # processing the later, it erroneously left in the csum tree 2 csum # items that overlapped each other, 1 for the sub-range [20K, 40K[ and # 1 for the whole range of our extent. This introduced a problem where # subsequent lookups for the checksums of blocks within the range # [40K, 100K[ of our extent would not find anything because lookups in # the csum tree ended up looking only at the smaller csum item, the # one covering the subrange [20K, 40K[. This made read requests assume # an expected checksum with a value of 0 for those blocks, which caused # checksum verification failure when the read operations finished. # However those checksum failure did not result in read requests # returning an error to user space (like -EIO for e.g.) because the # expected checksum value had the special value 0, and in that case # btrfs set all bytes of the corresponding pages with the value 0x01 # and produce the following warning in dmesg/syslog: # # "BTRFS warning (device dm-0): csum failed ino 257 off 917504 csum\ # 1322675045 expected csum 0" # _load_flakey_table $FLAKEY_ALLOW_WRITES _mount_flakey echo "File digest after log replay:" # Must match the same digest he had after cloning the extent and # before the power failure happened. md5sum $SCRATCH_MNT/foo | _filter_scratch _unmount_flakey status=0 exit Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: check if previous transaction aborted to avoid fs corruptionFilipe Manana2015-08-191-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While we are committing a transaction, it's possible the previous one is still finishing its commit and therefore we wait for it to finish first. However we were not checking if that previous transaction ended up getting aborted after we waited for it to commit, so we ended up committing the current transaction which can lead to fs corruption because the new superblock can point to trees that have had one or more nodes/leafs that were never durably persisted. The following sequence diagram exemplifies how this is possible: CPU 0 CPU 1 transaction N starts (...) btrfs_commit_transaction(N) cur_trans->state = TRANS_STATE_COMMIT_START; (...) cur_trans->state = TRANS_STATE_COMMIT_DOING; (...) cur_trans->state = TRANS_STATE_UNBLOCKED; root->fs_info->running_transaction = NULL; btrfs_start_transaction() --> starts transaction N + 1 btrfs_write_and_wait_transaction(trans, root); --> starts writing all new or COWed ebs created at transaction N creates some new ebs, COWs some existing ebs but doesn't COW or deletes eb X btrfs_commit_transaction(N + 1) (...) cur_trans->state = TRANS_STATE_COMMIT_START; (...) wait_for_commit(root, prev_trans); --> prev_trans == transaction N btrfs_write_and_wait_transaction() continues writing ebs --> fails writing eb X, we abort transaction N and set bit BTRFS_FS_STATE_ERROR on fs_info->fs_state, so no new transactions can start after setting that bit cleanup_transaction() btrfs_cleanup_one_transaction() wakes up task at CPU 1 continues, doesn't abort because cur_trans->aborted (transaction N + 1) is zero, and no checks for bit BTRFS_FS_STATE_ERROR in fs_info->fs_state are made btrfs_write_and_wait_transaction(trans, root); --> succeeds, no errors during writeback write_ctree_super(trans, root, 0); --> succeeds --> we have now a superblock that points us to some root that uses eb X, which was never written to disk In this scenario future attempts to read eb X from disk results in an error message like "parent transid verify failed on X wanted Y found Z". So fix this by aborting the current transaction if after waiting for the previous transaction we verify that it was aborted. Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: use __GFP_NOFAIL in alloc_btrfs_bioMichal Hocko2015-08-191-3/+1
| | | | | | | | | | | | | | | | | | alloc_btrfs_bio relies on GFP_NOFS allocation when committing the transaction but this allocation context is rather weak wrt. reclaim capabilities. The page allocator currently tries hard to not fail these allocations if they are small (<=PAGE_ALLOC_COSTLY_ORDER) but it can still fail if the _current_ process is the OOM killer victim. Moreover there is an attempt to move away from the default no-fail behavior and allow these allocation to fail more eagerly. This would lead to: [ 37.928625] kernel BUG at fs/btrfs/extent_io.c:4045 which is clearly undesirable and the nofail behavior should be explicit if the allocation failure cannot be tolerated. Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: Prevent from early transaction abortMichal Hocko2015-08-191-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Btrfs relies on GFP_NOFS allocation when committing the transaction but this allocation context is rather weak wrt. reclaim capabilities. The page allocator currently tries hard to not fail these allocations if they are small (<=PAGE_ALLOC_COSTLY_ORDER) so this is not a problem currently but there is an attempt to move away from the default no-fail behavior and allow these allocation to fail more eagerly. And this would lead to a pre-mature transaction abort as follows: [ 55.328093] Call Trace: [ 55.328890] [<ffffffff8154e6f0>] dump_stack+0x4f/0x7b [ 55.330518] [<ffffffff8108fa28>] ? console_unlock+0x334/0x363 [ 55.332738] [<ffffffff8110873e>] __alloc_pages_nodemask+0x81d/0x8d4 [ 55.334910] [<ffffffff81100752>] pagecache_get_page+0x10e/0x20c [ 55.336844] [<ffffffffa007d916>] alloc_extent_buffer+0xd0/0x350 [btrfs] [ 55.338973] [<ffffffffa0059d8c>] btrfs_find_create_tree_block+0x15/0x17 [btrfs] [ 55.341329] [<ffffffffa004f728>] btrfs_alloc_tree_block+0x18c/0x405 [btrfs] [ 55.343566] [<ffffffffa003fa34>] split_leaf+0x1e4/0x6a6 [btrfs] [ 55.345577] [<ffffffffa0040567>] btrfs_search_slot+0x671/0x831 [btrfs] [ 55.347679] [<ffffffff810682d7>] ? get_parent_ip+0xe/0x3e [ 55.349434] [<ffffffffa0041cb2>] btrfs_insert_empty_items+0x5d/0xa8 [btrfs] [ 55.351681] [<ffffffffa004ecfb>] __btrfs_run_delayed_refs+0x7a6/0xf35 [btrfs] [ 55.353979] [<ffffffffa00512ea>] btrfs_run_delayed_refs+0x6e/0x226 [btrfs] [ 55.356212] [<ffffffffa0060e21>] ? start_transaction+0x192/0x534 [btrfs] [ 55.358378] [<ffffffffa0060e21>] ? start_transaction+0x192/0x534 [btrfs] [ 55.360626] [<ffffffffa0060221>] btrfs_commit_transaction+0x4c/0xaba [btrfs] [ 55.362894] [<ffffffffa0060e21>] ? start_transaction+0x192/0x534 [btrfs] [ 55.365221] [<ffffffffa0073428>] btrfs_sync_file+0x29c/0x310 [btrfs] [ 55.367273] [<ffffffff81186808>] vfs_fsync_range+0x8f/0x9e [ 55.369047] [<ffffffff81186833>] vfs_fsync+0x1c/0x1e [ 55.370654] [<ffffffff81186869>] do_fsync+0x34/0x4e [ 55.372246] [<ffffffff81186ab3>] SyS_fsync+0x10/0x14 [ 55.373851] [<ffffffff81554f97>] system_call_fastpath+0x12/0x6f [ 55.381070] BTRFS: error (device hdb1) in btrfs_run_delayed_refs:2821: errno=-12 Out of memory [ 55.382431] BTRFS warning (device hdb1): Skipping commit of aborted transaction. [ 55.382433] BTRFS warning (device hdb1): cleanup_transaction:1692: Aborting unused transaction(IO failure). [ 55.384280] ------------[ cut here ]------------ [ 55.384312] WARNING: CPU: 0 PID: 3010 at fs/btrfs/delayed-ref.c:438 btrfs_select_ref_head+0xd9/0xfe [btrfs]() [...] [ 55.384337] Call Trace: [ 55.384353] [<ffffffff8154e6f0>] dump_stack+0x4f/0x7b [ 55.384357] [<ffffffff8107f717>] ? down_trylock+0x2d/0x37 [ 55.384359] [<ffffffff81046977>] warn_slowpath_common+0xa1/0xbb [ 55.384398] [<ffffffffa00a1d6b>] ? btrfs_select_ref_head+0xd9/0xfe [btrfs] [ 55.384400] [<ffffffff81046a34>] warn_slowpath_null+0x1a/0x1c [ 55.384423] [<ffffffffa00a1d6b>] btrfs_select_ref_head+0xd9/0xfe [btrfs] [ 55.384446] [<ffffffffa004e5f7>] ? __btrfs_run_delayed_refs+0xa2/0xf35 [btrfs] [ 55.384455] [<ffffffffa004e600>] __btrfs_run_delayed_refs+0xab/0xf35 [btrfs] [ 55.384476] [<ffffffffa00512ea>] btrfs_run_delayed_refs+0x6e/0x226 [btrfs] [ 55.384499] [<ffffffffa0060e21>] ? start_transaction+0x192/0x534 [btrfs] [ 55.384521] [<ffffffffa0060e21>] ? start_transaction+0x192/0x534 [btrfs] [ 55.384543] [<ffffffffa0060221>] btrfs_commit_transaction+0x4c/0xaba [btrfs] [ 55.384565] [<ffffffffa0060e21>] ? start_transaction+0x192/0x534 [btrfs] [ 55.384588] [<ffffffffa0073428>] btrfs_sync_file+0x29c/0x310 [btrfs] [ 55.384591] [<ffffffff81186808>] vfs_fsync_range+0x8f/0x9e [ 55.384592] [<ffffffff81186833>] vfs_fsync+0x1c/0x1e [ 55.384593] [<ffffffff81186869>] do_fsync+0x34/0x4e [ 55.384594] [<ffffffff81186ab3>] SyS_fsync+0x10/0x14 [ 55.384595] [<ffffffff81554f97>] system_call_fastpath+0x12/0x6f [...] [ 55.384608] ---[ end trace c29799da1d4dd621 ]--- [ 55.437323] BTRFS info (device hdb1): forced readonly [ 55.438815] BTRFS info (device hdb1): delayed_refs has NO entry Fix this by being explicit about the no-fail behavior of this allocation path and use __GFP_NOFAIL. Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: Remove unused arguments in tree-log.cZhaolei2015-08-191-14/+11
| | | | | | | | | | | | Following arguments are not used in tree-log.c: insert_one_name(): path, type wait_log_commit(): trans wait_for_writer(): trans This patch remove them. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: Remove useless condition in start_log_trans()Zhaolei2015-08-191-26/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Dan Carpenter <dan.carpenter@oracle.com> reported a smatch warning for start_log_trans(): fs/btrfs/tree-log.c:178 start_log_trans() warn: we tested 'root->log_root' before and it was 'false' fs/btrfs/tree-log.c 147 if (root->log_root) { We test "root->log_root" here. ... Reason: Condition of: fs/btrfs/tree-log.c:178: if (!root->log_root) { is not necessary after commit: 7237f1833 It caused a smatch warning, and no functionally error. Fix: Deleting above condition will make smatch shut up, but a better way is to do cleanup for start_log_trans() to remove duplicated code and make code more readable. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* Merge branch 'jeffm-discard-4.3' into for-linus-4.3Chris Mason2015-08-099-58/+342
|\
| * btrfs: add missing discards when unpinning extents with -o discardJeff Mahoney2015-07-296-29/+105
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we clear the dirty bits in btrfs_delete_unused_bgs for extents in the empty block group, it results in btrfs_finish_extent_commit being unable to discard the freed extents. The block group removal patch added an alternate path to forget extents other than btrfs_finish_extent_commit. As a result, any extents that would be freed when the block group is removed aren't discarded. In my test run, with a large copy of mixed sized files followed by removal, it left nearly 2/3 of extents undiscarded. To clean up the block groups, we add the removed block group onto a list that will be discarded after transaction commit. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * btrfs: explictly delete unused block groups in close_ctree and ro-remountJeff Mahoney2015-07-292-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cleaner thread may already be sleeping by the time we enter close_ctree. If that's the case, we'll skip removing any unused block groups queued for removal, even during a normal umount. They'll be cleaned up automatically at next mount, but users expect a umount to be a clean synchronization point, especially when used on thin-provisioned storage with -odiscard. We also explicitly remove unused block groups in the ro-remount path for the same reason. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * btrfs: iterate over unused chunk space in FITRIMJeff Mahoney2015-07-293-24/+143
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since we now clean up block groups automatically as they become empty, iterating over block groups is no longer sufficient to discard unused space. This patch iterates over the unused chunk space and discards any regions that are unallocated, regardless of whether they were ever used. This is a change for btrfs but is consistent with other file systems. We do this in a transactionless manner since the discard process can take a substantial amount of time and a transaction would need to be started before the acquisition of the device list lock. That would mean a transaction would be held open across /all/ of the discards collectively. In order to prevent other threads from allocating or freeing chunks, we hold the chunks lock across the search and discard calls. We release it between searches to allow the file system to perform more-or-less normally. Since the running transaction can commit and disappear while we're using the transaction pointer, we take a reference to it and release it after the search. This is safe since it would happen normally at the end of the transaction commit after any locks are released anyway. We also take the commit_root_sem to protect against a transaction starting and committing while we're running. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * btrfs: skip superblocks during discardJeff Mahoney2015-07-291-4/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Btrfs doesn't track superblocks with extent records so there is nothing persistent on-disk to indicate that those blocks are in use. We track the superblocks in memory to ensure they don't get used by removing them from the free space cache when we load a block group from disk. Prior to 47ab2a6c6a (Btrfs: remove empty block groups automatically), that was fine since the block group would never be reclaimed so the superblock was always safe. Once we started removing the empty block groups, we were protected by the fact that discards weren't being properly issued for unused space either via FITRIM or -odiscard. The block groups were still being released, but the blocks remained on disk. In order to properly discard unused block groups, we need to filter out the superblocks from the discard range. Superblocks are located at fixed locations on each device, so it makes sense to filter them out in btrfs_issue_discard, which is used by both -odiscard and FITRIM. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * btrfs: btrfs_issue_discard ensure offset/length are aligned to sector boundariesJeff Mahoney2015-07-291-4/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's possible, though unexpected, to pass unaligned offsets and lengths to btrfs_issue_discard. We then shift the offset/length values to sector units. If an unaligned offset has been passed, it will result in the entire sector being discarded, possibly losing data. An unaligned length is safe but we'll end up returning an inaccurate number of discarded bytes. This patch aligns the offset to the 512B boundary, adjusts the length, and warns, since we shouldn't be discarding on an offset that isn't aligned with our sector size. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
| * btrfs: make btrfs_issue_discard return bytes discardedJeff Mahoney2015-07-291-5/+14
| | | | | | | | | | | | | | | | | | | | | | Initially this will just be the length argument passed to it, but the following patches will adjust that to reflect re-alignment and skipped blocks. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Tested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* | Btrfs: add support for blkio controllersChris Mason2015-08-095-4/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This attaches accounting information to bios as we submit them so the new blkio controllers can throttle on btrfs filesystems. Not much is required, we're just associating bios with blkcgs during clone, calling wbc_init_bio()/wbc_account_io() during writepages submission, and attaching the bios to the current context during direct IO. Finally if we are splitting bios during btrfs_map_bio, this attaches accounting information to the split. The end result is able to throttle nicely on single disk filesystems. A little more work is required for multi-device filesystems. Signed-off-by: Chris Mason <clm@fb.com>
* | Btrfs: remove unused mutex from struct 'btrfs_fs_info'Byongho Lee2015-08-092-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The code using 'ordered_extent_flush_mutex' mutex has removed by below commit. - 8d875f95da43c6a8f18f77869f2ef26e9594fecc btrfs: disable strict file flushes for renames and truncates But the mutex still lives in struct 'btrfs_fs_info'. So, this patch removes the mutex from struct 'btrfs_fs_info' and its initialization code. Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* | Btrfs: fix parity scrub of RAID 5/6 with missing deviceOmar Sandoval2015-08-091-4/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When testing the previous patch, Zhao Lei reported a similar bug when attempting to scrub a degraded RAID 5/6 filesystem with a missing device, leading to NULL pointer dereferences from the RAID 5/6 parity scrubbing code. The first cause was the same as in the previous patch: attempting to call bio_add_page() on a missing block device. To fix this, scrub_extent_for_parity() can just mark the sectors on the missing device as errors instead of attempting to read from it. Additionally, the code uses scrub_remap_extent() to map the extent of the corresponding data stripe, but the extent wasn't already mapped. If scrub_remap_extent() finds a missing block device, it doesn't initialize extent_dev, so we're left with a NULL struct btrfs_device. The solution is to use btrfs_map_block() directly. Reported-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
* | Btrfs: fix device replace of a missing RAID 5/6 deviceOmar Sandoval2015-08-091-10/+147
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The original implementation of device replace on RAID 5/6 seems to have missed support for replacing a missing device. When this is attempted, we end up calling bio_add_page() on a bio with a NULL ->bi_bdev, which crashes when we try to dereference it. This happens because btrfs_map_block() has no choice but to return us the missing device because RAID 5/6 don't have any alternate mirrors to read from, and a missing device has a NULL bdev. The idea implemented here is to handle the missing device case separately, which better only happen when we're replacing a missing RAID 5/6 device. We use the new BTRFS_RBIO_REBUILD_MISSING operation to reconstruct the data from parity, check it with scrub_recheck_block_checksum(), and write it out with scrub_write_block_to_dev_replace(). Reported-by: Philip <bugzilla@philip-seeger.de> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=96141 Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
* | Btrfs: add RAID 5/6 BTRFS_RBIO_REBUILD_MISSING operationOmar Sandoval2015-08-093-14/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | The current RAID 5/6 recovery code isn't quite prepared to handle missing devices. In particular, it expects a bio that we previously attempted to use in the read path, meaning that it has valid pages allocated. However, missing devices have a NULL blkdev, and we can't call bio_add_page() on a bio with a NULL blkdev. We could do manual manipulation of bio->bi_io_vec, but that's pretty gross. So instead, add a separate path that allows us to manually add pages to the rbio. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
* | Btrfs: count devices correctly in readahead during RAID 5/6 replaceOmar Sandoval2015-08-091-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 5fbc7c59fd22 ("Btrfs: fix unfinished readahead thread for raid5/6 degraded mounting") fixed a problem where we would skip a missing device when we shouldn't have because there are no other mirrors to read from in RAID 5/6. After commit 2c8cdd6ee4e7 ("Btrfs, replace: write dirty pages into the replace target device"), the fix doesn't work when we're doing a missing device replace on RAID 5/6 because the replace device is counted as a mirror so we're tricked into thinking we can safely skip the missing device. The fix is to count only the real stripes and decide based on that. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
* | Btrfs: remove misleading handling of missing device scrubOmar Sandoval2015-08-091-15/+1
| | | | | | | | | | | | | | | | | | | | scrub_submit() claims that it can handle a bio with a NULL block device, but this is misleading, as calling bio_add_page() on a bio with a NULL ->bi_bdev would've already crashed. Delete this, as we're about to properly handle a missing block device. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
* | btrfs: fix clone / extent-same deadlocksMark Fasheh2015-08-091-26/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clone and extent same lock their source and target inodes in opposite order. In addition to this, the range locking in clone doesn't take ordering into account. Fix this by having clone use the same locking helpers as btrfs-extent-same. In addition, I do a small cleanup of the locking helpers, removing a case (both inodes being the same) which was poorly accounted for and never actually used by the callers. Signed-off-by: Mark Fasheh <mfasheh@suse.de> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
* | Btrfs: fix defrag to merge tail file extentLiu Bo2015-08-091-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The file layout is [extent 1]...[extent n][4k extent][HOLE][extent x] extent 1~n and 4k extent can be merged during defrag, and the whole defrag bytes is larger than our defrag thresh(256k), 4k extent as a tail is left unmerged since we check if its next extent can be merged (the next one is a hole, so the check will fail), the layout thus can be [new extent][4k extent][HOLE][extent x] (1~n) To fix it, beside looking at the next one, this also looks at the previous one by checking @defrag_end, which is set to 0 when we decide to stop merging contiguous extents, otherwise, we can merge the previous one with our extent. Also, this makes btrfs behave consistent with how xfs and ext4 do. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
* | Btrfs: fix warning in backref walkingLiu Bo2015-08-091-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we do backref walking, we search firstly in queued delayed refs and then the on-disk backrefs, but we parse differently for shared references, for delayed refs we also add 'ref->root' while for on-disk backrefs we don't, this can prevent us from merging refs indexed by the same bytenr and cause find_parent_nodes() to throw a warning at 'WARN_ON(ref->count < 0)', for example, when we have a shared data extent with 'ref_cnt=1' and a delayed shared data with a BTRFS_DROP_DELAYED_REF, that happens. For shared references, no matter if it's delayed or on-disk, ref->root is not at all used, instead it's ref->parent that really matters, so this has delayed refs handled as the same way as on-disk refs. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
* | btrfs: Add WARN_ON() for double lock in btrfs_tree_lock()Zhaolei2015-08-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | When a task trying to double lock a extent buffer, there are no lockdep warning about it because this lock may be in "blocking_lock" state, and make us hard to debug. This patch add a WARN_ON() for above condition, it can not report all deadlock cases(as lock between tasks), but at least helps us some. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* | btrfs: Remove root argument in extent_data_ref_count()Zhaolei2015-08-091-3/+2
| | | | | | | | | | | | | | Because it is never used. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* | btrfs: Fix wrong comment of btrfs_alloc_tree_block()Zhaolei2015-08-091-3/+0
| | | | | | | | | | | | | | | | These wrong comment was copyed from another function(expired) from init, this patch fixed them. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* | btrfs: abort transaction on btrfs_reloc_cow_block()Zhaolei2015-08-091-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When btrfs_reloc_cow_block() failed in __btrfs_cow_block(), current code just return a err-value to caller, but leave new_created extent buffer exist and locked. Then subsequent code (in relocate) try to lock above eb again, and caused deadlock without any dmesg. (eb lock use wait_event(), so no lockdep message) It is hard to do recover work in __btrfs_cow_block() at this error point, but we can abort transaction to avoid deadlock and operate on unstable state.a It also helps developer to find wrong place quickly. (better than a frozen fs without any dmesg before patch) Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* | btrfs: Remove unnecessary variants in relocation.cZhaolei2015-08-093-11/+7
| | | | | | | | | | | | | | | | These arguments are not used in functions, remove them for cleanup and make kernel stack happy. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* | btrfs: Cleanup: Remove chunk_objectid argument from btrfs_relocate_chunk()Zhaolei2015-08-091-8/+2
| | | | | | | | | | | | | | | | | | | | Remove chunk_objectid argument from btrfs_relocate_chunk() because it is not necessary, it can also cleanup some code in caller for prepare its value. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
* | btrfs: Cleanup: Remove objectid's init-value in create_reloc_inode()Zhaolei2015-08-091-1/+1
| | | | | | | | | | | | | | | | objectid's init-value is not used in any case, remove it. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
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