- 26 Apr, 2017 3 commits
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Filipe Manana authored
When attempting to COW a file range (we are starting writeback and doing COW), if we manage to reserve an extent for the range we will write into but fail after reserving it and before creating the respective ordered extent, we end up in an error path where we attempt to decrement the data space's bytes_may_use counter after we already did it while reserving the extent, leading to a warning/trace like the following: [ 847.621524] ------------[ cut here ]------------ [ 847.625441] WARNING: CPU: 5 PID: 4905 at fs/btrfs/extent-tree.c:4316 btrfs_free_reserved_data_space_noquota+0x60/0x9f [btrfs] [ 847.633704] Modules linked in: btrfs crc32c_generic xor raid6_pq acpi_cpufreq i2c_piix4 ppdev psmouse tpm_tis serio_raw pcspkr parport_pc tpm_tis_core i2c_core sg [ 847.644616] CPU: 5 PID: 4905 Comm: xfs_io Not tainted 4.10.0-rc8-btrfs-next-37+ #2 [ 847.648601] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 847.648601] Call Trace: [ 847.648601] dump_stack+0x67/0x90 [ 847.648601] __warn+0xc2/0xdd [ 847.648601] warn_slowpath_null+0x1d/0x1f [ 847.648601] btrfs_free_reserved_data_space_noquota+0x60/0x9f [btrfs] [ 847.648601] btrfs_clear_bit_hook+0x140/0x258 [btrfs] [ 847.648601] clear_state_bit+0x87/0x128 [btrfs] [ 847.648601] __clear_extent_bit+0x222/0x2b7 [btrfs] [ 847.648601] clear_extent_bit+0x17/0x19 [btrfs] [ 847.648601] extent_clear_unlock_delalloc+0x3b/0x6b [btrfs] [ 847.648601] cow_file_range.isra.39+0x387/0x39a [btrfs] [ 847.648601] run_delalloc_nocow+0x4d7/0x70e [btrfs] [ 847.648601] ? arch_local_irq_save+0x9/0xc [ 847.648601] run_delalloc_range+0xa7/0x2b5 [btrfs] [ 847.648601] writepage_delalloc.isra.31+0xb9/0x15c [btrfs] [ 847.648601] __extent_writepage+0x249/0x2e8 [btrfs] [ 847.648601] extent_write_cache_pages.constprop.33+0x28b/0x36c [btrfs] [ 847.648601] ? arch_local_irq_save+0x9/0xc [ 847.648601] ? mark_lock+0x24/0x201 [ 847.648601] extent_writepages+0x4b/0x5c [btrfs] [ 847.648601] ? btrfs_writepage_start_hook+0xed/0xed [btrfs] [ 847.648601] btrfs_writepages+0x28/0x2a [btrfs] [ 847.648601] do_writepages+0x23/0x2c [ 847.648601] __filemap_fdatawrite_range+0x5a/0x61 [ 847.648601] filemap_fdatawrite_range+0x13/0x15 [ 847.648601] btrfs_fdatawrite_range+0x20/0x46 [btrfs] [ 847.648601] start_ordered_ops+0x19/0x23 [btrfs] [ 847.648601] btrfs_sync_file+0x136/0x42c [btrfs] [ 847.648601] vfs_fsync_range+0x8c/0x9e [ 847.648601] vfs_fsync+0x1c/0x1e [ 847.648601] do_fsync+0x31/0x4a [ 847.648601] SyS_fsync+0x10/0x14 [ 847.648601] entry_SYSCALL_64_fastpath+0x18/0xad [ 847.648601] RIP: 0033:0x7f5b05200800 [ 847.648601] RSP: 002b:00007ffe204f71c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004a [ 847.648601] RAX: ffffffffffffffda RBX: ffffffff8109637b RCX: 00007f5b05200800 [ 847.648601] RDX: 00000000008bd0a0 RSI: 00000000008bd2e0 RDI: 0000000000000003 [ 847.648601] RBP: ffffc90001d67f98 R08: 000000000000ffff R09: 000000000000001f [ 847.648601] R10: 00000000000001f6 R11: 0000000000000246 R12: 0000000000000046 [ 847.648601] R13: ffffc90001d67f78 R14: 00007f5b054be740 R15: 00007f5b054be740 [ 847.648601] ? trace_hardirqs_off_caller+0x3f/0xaa [ 847.685787] ---[ end trace 2a4a3e15382508e8 ]--- So fix this by not attempting to decrement the data space info's bytes_may_use counter if we already reserved the extent and an error happened before creating the ordered extent. We are already correctly freeing the reserved extent if an error happens, so there's no additional measure needed. Signed-off-by:
Filipe Manana <fdmanana@suse.com> Reviewed-by:
Liu Bo <bo.li.liu@oracle.com>
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Qu Wenruo authored
[BUG] If run_delalloc_range() returns error and there is already some ordered extents created, btrfs will be hanged with the following backtrace: Call Trace: __schedule+0x2d4/0xae0 schedule+0x3d/0x90 btrfs_start_ordered_extent+0x160/0x200 [btrfs] ? wake_atomic_t_function+0x60/0x60 btrfs_run_ordered_extent_work+0x25/0x40 [btrfs] btrfs_scrubparity_helper+0x1c1/0x620 [btrfs] btrfs_flush_delalloc_helper+0xe/0x10 [btrfs] process_one_work+0x2af/0x720 ? process_one_work+0x22b/0x720 worker_thread+0x4b/0x4f0 kthread+0x10f/0x150 ? process_one_work+0x720/0x720 ? kthread_create_on_node+0x40/0x40 ret_from_fork+0x2e/0x40 [CAUSE] |<------------------ delalloc range --------------------------->| | OE 1 | OE 2 | ... | OE n | |<>| |<---------- cleanup range --------->| || \_=> First page handled by end_extent_writepage() in __extent_writepage() The problem is caused by error handler of run_delalloc_range(), which doesn't handle any created ordered extents, leaving them waiting on btrfs_finish_ordered_io() to finish. However after run_delalloc_range() returns error, __extent_writepage() won't submit bio, so btrfs_writepage_end_io_hook() won't be triggered except the first page, and btrfs_finish_ordered_io() won't be triggered for created ordered extents either. So OE 2~n will hang forever, and if OE 1 is larger than one page, it will also hang. [FIX] Introduce btrfs_cleanup_ordered_extents() function to cleanup created ordered extents and finish them manually. The function is based on existing btrfs_endio_direct_write_update_ordered() function, and modify it to act just like btrfs_writepage_endio_hook() but handles specified range other than one page. After fix, delalloc error will be handled like: |<------------------ delalloc range --------------------------->| | OE 1 | OE 2 | ... | OE n | |<>|<-------- ----------->|<------ old error handler --------->| || || || \_=> Cleaned up by cleanup_ordered_extents() \_=> First page handled by end_extent_writepage() in __extent_writepage() Signed-off-by:
Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by:
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Qu Wenruo authored
[BUG] When btrfs_reloc_clone_csum() reports error, it can underflow metadata and leads to kernel assertion on outstanding extents in run_delalloc_nocow() and cow_file_range(). BTRFS info (device vdb5): relocating block group 12582912 flags data BTRFS info (device vdb5): found 1 extents assertion failed: inode->outstanding_extents >= num_extents, file: fs/btrfs//extent-tree.c, line: 5858 Currently, due to another bug blocking ordered extents, the bug is only reproducible under certain block group layout and using error injection. a) Create one data block group with one 4K extent in it. To avoid the bug that hangs btrfs due to ordered extent which never finishes b) Make btrfs_reloc_clone_csum() always fail c) Relocate that block group [CAUSE] run_delalloc_nocow() and cow_file_range() handles error from btrfs_reloc_clone_csum() wrongly: (The ascii chart shows a more generic case of this bug other than the bug mentioned above) |<------------------ delalloc range --------------------------->| | OE 1 | OE 2 | ... | OE n | |<----------- cleanup range --------------->| |<----------- ----------->| \/ btrfs_finish_ordered_io() range So error handler, which calls extent_clear_unlock_delalloc() with EXTENT_DELALLOC and EXTENT_DO_ACCOUNT bits, and btrfs_finish_ordered_io() will both cover OE n, and free its metadata, causing metadata under flow. [Fix] The fix is to ensure after calling btrfs_add_ordered_extent(), we only call error handler after increasing the iteration offset, so that cleanup range won't cover any created ordered extent. |<------------------ delalloc range --------------------------->| | OE 1 | OE 2 | ... | OE n | |<----------- ----------->|<---------- cleanup range --------->| \/ btrfs_finish_ordered_io() range Signed-off-by:
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- 11 Apr, 2017 4 commits
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Liu Bo authored
KASAN reports that there is a use-after-free case of bio in btrfs_map_bio. If we need to submit IOs to several disks at a time, the original bio would get cloned and mapped to the destination disk, but we really should use the original bio instead of a cloned bio to do the sanity check because cloned bios are likely to be freed by its endio. Reported-by:
Diego <diegocg@gmail.com> Signed-off-by:
David Sterba <dsterba@suse.com> Signed-off-by:
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Liu Bo authored
Commit 2dabb324 ("Btrfs: Direct I/O read: Work on sectorsized blocks") introduced this bug during iterating bio pages in dio read's endio hook, and it could end up with segment fault of the dio reading task. So the reason is 'if (nr_sectors--)', and it makes the code assume that there is one more block in the same page, so page offset is increased and the bio which is created to repair the bad block then has an incorrect bvec.bv_offset, and a later access of the page content would throw a segmentation fault. This also adds ASSERT to check page offset against page size. Signed-off-by:
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Liu Bo authored
When doing directIO repair, we have this oops: [ 1458.532816] general protection fault: 0000 [#1] SMP ... [ 1458.536291] Workqueue: btrfs-endio-repair btrfs_endio_repair_helper [btrfs] [ 1458.536893] task: ffff88082a42d100 task.stack: ffffc90002b3c000 [ 1458.537499] RIP: 0010:btrfs_retry_endio+0x7e/0x1a0 [btrfs] ... [ 1458.543261] Call Trace: [ 1458.543958] ? rcu_read_lock_sched_held+0xc4/0xd0 [ 1458.544374] bio_endio+0xed/0x100 [ 1458.544750] end_workqueue_fn+0x3c/0x40 [btrfs] [ 1458.545257] normal_work_helper+0x9f/0x900 [btrfs] [ 1458.545762] btrfs_endio_repair_helper+0x12/0x20 [btrfs] [ 1458.546224] process_one_work+0x34d/0xb70 [ 1458.546570] ? process_one_work+0x29e/0xb70 [ 1458.546938] worker_thread+0x1cf/0x960 [ 1458.547263] ? process_one_work+0xb70/0xb70 [ 1458.547624] kthread+0x17d/0x180 [ 1458.547909] ? kthread_create_on_node+0x70/0x70 [ 1458.548300] ret_from_fork+0x31/0x40 It turns out that btrfs_retry_endio is trying to get inode from a directIO page. This fixes the problem by using the saved inode pointer, done->inode. btrfs_retry_endio_nocsum has the same problem, and it's fixed as well. Also cleanup unused @start (which is too trivial for a separate patch). Cc: David Sterba <dsterba@suse.cz> Signed-off-by:
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Adam Borowski authored
The opposite case was already handled right in the very next switch entry. And also when turning on nossd, drop ssd_spread. Reported-by:
Hans van Kranenburg <hans.van.kranenburg@mendix.com> Signed-off-by:
Adam Borowski <kilobyte@angband.pl> Reviewed-by:
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- 29 Mar, 2017 4 commits
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Chris Mason authored
Merge branch 'for-chris-4.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.11
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Dan Carpenter authored
This isn't super serious because you need CAP_ADMIN to run this code. I added this integer overflow check last year but apparently I am rubbish at writing integer overflow checks... There are two issues. First, access_ok() works on unsigned long type and not u64 so on 32 bit systems the access_ok() could be checking a truncated size. The other issue is that we should be using a stricter limit so we don't overflow the kzalloc() setting ctx->clone_roots later in the function after the access_ok(): alloc_size = sizeof(struct clone_root) * (arg->clone_sources_count + 1); sctx->clone_roots = kzalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN); Fixes: f5ecec3c ("btrfs: send: silence an integer overflow warning") Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by:
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Goldwyn Rodrigues authored
Using an int value is causing qg->reserved to become negative and exclusive -EDQUOT to be reached prematurely. This affects exclusive qgroups only. TEST CASE: DEVICE=/dev/vdb MOUNTPOINT=/mnt SUBVOL=$MOUNTPOINT/tmp umount $SUBVOL umount $MOUNTPOINT mkfs.btrfs -f $DEVICE mount /dev/vdb $MOUNTPOINT btrfs quota enable $MOUNTPOINT btrfs subvol create $SUBVOL umount $MOUNTPOINT mount /dev/vdb $MOUNTPOINT mount -o subvol=tmp $DEVICE $SUBVOL btrfs qgroup limit -e 3G $SUBVOL btrfs quota rescan /mnt -w for i in `seq 1 44000`; do dd if=/dev/zero of=/mnt/tmp/test_$i bs=10k count=1 if [[ $? > 0 ]]; then btrfs qgroup show -pcref $SUBVOL exit 1 fi done Signed-off-by:Goldwyn Rodrigues <rgoldwyn@suse.com> [ add reproducer to changelog ] Signed-off-by:
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Liu Bo authored
Commit 20a7db8a ("btrfs: add dummy callback for readpage_io_failed and drop checks") made a cleanup around readpage_io_failed_hook, and it was supposed to keep the original sematics, but it also unexpectedly disabled repair during read for dup, raid1 and raid10. This fixes the problem by letting data's inode call the generic readpage_io_failed callback by returning -EAGAIN from its readpage_io_failed_hook in order to notify end_bio_extent_readpage to do the rest. We don't call it directly because the generic one takes an offset from end_bio_extent_readpage() to calculate the index in the checksum array and inode's readpage_io_failed_hook doesn't offer that offset. Cc: David Sterba <dsterba@suse.cz> Signed-off-by:
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- 17 Mar, 2017 2 commits
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Zygo Blaxell authored
This is a story about 4 distinct (and very old) btrfs bugs. Commit c8b97818 ("Btrfs: Add zlib compression support") added three data corruption bugs for inline extents (bugs #1-3). Commit 93c82d57 ("Btrfs: zero page past end of inline file items") fixed bug #1: uncompressed inline extents followed by a hole and more extents could get non-zero data in the hole as they were read. The fix was to add a memset in btrfs_get_extent to zero out the hole. Commit 166ae5a4 ("btrfs: fix inline compressed read err corruption") fixed bug #2: compressed inline extents which contained non-zero bytes might be replaced with zero bytes in some cases. This patch removed an unhelpful memset from uncompress_inline, but the case where memset is required was missed. There is also a memset in the decompression code, but this only covers decompressed data that is shorter than the ram_bytes from the extent ref record. This memset doesn't cover the region between the end of the decompressed data and the end of the page. It has also moved around a few times over the years, so there's no single patch to refer to. This patch fixes bug #3: compressed inline extents followed by a hole and more extents could get non-zero data in the hole as they were read (i.e. bug #3 is the same as bug #1, but s/uncompressed/compressed/). The fix is the same: zero out the hole in the compressed case too, by putting a memset back in uncompress_inline, but this time with correct parameters. The last and oldest bug, bug #0, is the cause of the offending inline extent/hole/extent pattern. Bug #0 is a subtle and mostly-harmless quirk of behavior somewhere in the btrfs write code. In a few special cases, an inline extent and hole are allowed to persist where they normally would be combined with later extents in the file. A fast reproducer for bug #0 is presented below. A few offending extents are also created in the wild during large rsync transfers with the -S flag. A Linux kernel build (git checkout; make allyesconfig; make -j8) will produce a handful of offending files as well. Once an offending file is created, it can present different content to userspace each time it is read. Bug #0 is at least 4 and possibly 8 years old. I verified every vX.Y kernel back to v3.5 has this behavior. There are fossil records of this bug's effects in commits all the way back to v2.6.32. I have no reason to believe bug #0 wasn't present at the beginning of btrfs compression support in v2.6.29, but I can't easily test kernels that old to be sure. It is not clear whether bug #0 is worth fixing. A fix would likely require injecting extra reads into currently write-only paths, and most of the exceptional cases caused by bug #0 are already handled now. Whether we like them or not, bug #0's inline extents followed by holes are part of the btrfs de-facto disk format now, and we need to be able to read them without data corruption or an infoleak. So enough about bug #0, let's get back to bug #3 (this patch). An example of on-disk structure leading to data corruption found in the wild: item 61 key (606890 INODE_ITEM 0) itemoff 9662 itemsize 160 inode generation 50 transid 50 size 47424 nbytes 49141 block group 0 mode 100644 links 1 uid 0 gid 0 rdev 0 flags 0x0(none) item 62 key (606890 INODE_REF 603050) itemoff 9642 itemsize 20 inode ref index 3 namelen 10 name: DB_File.so item 63 key (606890 EXTENT_DATA 0) itemoff 8280 itemsize 1362 inline extent data size 1341 ram 4085 compress(zlib) item 64 key (606890 EXTENT_DATA 4096) itemoff 8227 itemsize 53 extent data disk byte 5367308288 nr 20480 extent data offset 0 nr 45056 ram 45056 extent compression(zlib) Different data appears in userspace during each read of the 11 bytes between 4085 and 4096. The extent in item 63 is not long enough to fill the first page of the file, so a memset is required to fill the space between item 63 (ending at 4085) and item 64 (beginning at 4096) with zero. Here is a reproducer from Liu Bo, which demonstrates another method of creating the same inline extent and hole pattern: Using 'page_poison=on' kernel command line (or enable CONFIG_PAGE_POISONING) run the following: # touch foo # chattr +c foo # xfs_io -f -c "pwrite -W 0 1000" foo # xfs_io -f -c "falloc 4 8188" foo # od -x foo # echo 3 >/proc/sys/vm/drop_caches # od -x foo This produce the following on my box: Correct output: file contains 1000 data bytes followed by zeros: 0000000 cdcd cdcd cdcd cdcd cdcd cdcd cdcd cdcd * 0001740 cdcd cdcd cdcd cdcd 0000 0000 0000 0000 0001760 0000 0000 0000 0000 0000 0000 0000 0000 * 0020000 Actual output: the data after the first 1000 bytes will be different each run: 0000000 cdcd cdcd cdcd cdcd cdcd cdcd cdcd cdcd * 0001740 cdcd cdcd cdcd cdcd 6c63 7400 635f 006d 0001760 5f74 6f43 7400 435f 0053 5f74 7363 7400 0002000 435f 0056 5f74 6164 7400 645f 0062 5f74 (...) Signed-off-by:
Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by:
Chris Mason <clm@fb.com> Signed-off-by:
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Liu Bo authored
The bug is a regression after commit (da2c7009 "btrfs: teach __process_pages_contig about PAGE_LOCK operation") and commit (76c0021d "Btrfs: use helper to simplify lock/unlock pages"). So if the dirty pages which are under writeback got truncated partially before we lock the dirty pages, we couldn't find all pages mapping to the delalloc range, and the bug didn't return an error so it kept going on and found that the delalloc range got truncated and got to unlock the dirty pages, and then the ASSERT could caught the error, and showed ----------------------------------------------------------------------------- assertion failed: page_ops & PAGE_LOCK, file: fs/btrfs/extent_io.c, line: 1716 ----------------------------------------------------------------------------- This fixes the bug by returning the proper -EAGAIN. Cc: David Sterba <dsterba@suse.com> Reported-by:
Dave Jones <davej@codemonkey.org.uk> Signed-off-by:
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- 07 Mar, 2017 1 commit
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Dmitry V. Levin authored
btrfs_err_str function is not called from anywhere and is replicated in the userspace headers for btrfs-progs. It's removal also fixes the following linux/btrfs.h userspace compilation error: /usr/include/linux/btrfs.h: In function 'btrfs_err_str': /usr/include/linux/btrfs.h:740:11: error: 'NULL' undeclared (first use in this function) return NULL; Suggested-by:Jeff Mahoney <jeffm@suse.com> Signed-off-by:
Dmitry V. Levin <ldv@altlinux.org> Reviewed-by:
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- 28 Feb, 2017 26 commits
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Chris Mason authored
Merge branch 'for-chris-4.11-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.11
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David Sterba authored
Make extent_io_ops::readpage_io_failed_hook callback mandatory and define a dummy function for btrfs_extent_io_ops. As the failed IO callback is not performance critical, the branch vs extra trade off does not hurt. Signed-off-by: -
David Sterba authored
We know that eadpage_end_io_hook, submit_bio_hook and merge_bio_hook are always defined so we can drop the checks before we call them. Signed-off-by: -
David Sterba authored
Some of the callbacks defined in btree_extent_io_ops and btrfs_extent_io_ops do always exist so we don't need to check the existence before each call. This patch just reorders the definition and documents which are mandatory/optional. Signed-off-by: -
David Sterba authored
There's no error path in any of the instances, always return 0. Reviewed-by:
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David Sterba authored
The space check in btrfs_insert_xattr_item is duplicated in it's caller (do_setxattr) so we won't hit the BUG_ON. Continuing without any check could be disasterous so turn it to a proper error handling. Reviewed-by:
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David Sterba authored
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David Sterba authored
All callers dereference the 'tm' parameter before it gets to this function, the NULL check does not make much sense here. Reviewed-by:
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David Sterba authored
The value of max_out can be calculated from the parameters passed to the compressors, which is number of pages and the page size, and we don't have to needlessly pass it around. Signed-off-by: -
David Sterba authored
Signed-off-by: -
David Sterba authored
Move the buffer limit definitions out of compress_file_range. Reviewed-by:
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David Sterba authored
The parameter saying how many pages can be allocated at maximum can be merged with the output page counter, to save some stack space. The compression implementation will sink the parameter to a local variable so everything works as before. The nr_pages variables can also be simply merged in compress_file_range into one. Signed-off-by: -
David Sterba authored
The length parameter is basically duplicated for input and output in the top level caller of the compress_pages chain. We can simply use one variable for that and reduce stack consumption. The compression implementation will sink the parameter to a local variable so everything works as before. Signed-off-by: -
David Sterba authored
Signed-off-by: -
David Sterba authored
Signed-off-by: -
David Sterba authored
The function does not modify the input buffer, also update a typecast in one caller. Signed-off-by: -
David Sterba authored
Signed-off-by: -
Nikolay Borisov authored
Signed-off-by:
Nikolay Borisov <nborisov@suse.com> Signed-off-by:
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Nikolay Borisov authored
Signed-off-by:
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Nikolay Borisov authored
Signed-off-by:
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Nikolay Borisov authored
Signed-off-by:
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Nikolay Borisov authored
Signed-off-by:
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Nikolay Borisov authored
In addition to changing the signature, this patch also switches all the functions which are used as an argument to also take btrfs_inode. Namely those are: btrfs_get_extent and btrfs_get_extent_filemap. Signed-off-by:
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Nikolay Borisov authored
Signed-off-by:
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Nikolay Borisov authored
Signed-off-by:
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Nikolay Borisov authored
Signed-off-by:
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