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2019-09-12Btrfs: incremental send, fix file corruption when no-holes feature is enabledFilipe Manana
commit 6b1f72e5b82a5c2a4da4d1ebb8cc01913ddbea21 upstream. When using the no-holes feature, if we have a file with prealloc extents with a start offset beyond the file's eof, doing an incremental send can cause corruption of the file due to incorrect hole detection. Such case requires that the prealloc extent(s) exist in both the parent and send snapshots, and that a hole is punched into the file that covers all its extents that do not cross the eof boundary. Example reproducer: $ mkfs.btrfs -f -O no-holes /dev/sdb $ mount /dev/sdb /mnt/sdb $ xfs_io -f -c "pwrite -S 0xab 0 500K" /mnt/sdb/foobar $ xfs_io -c "falloc -k 1200K 800K" /mnt/sdb/foobar $ btrfs subvolume snapshot -r /mnt/sdb /mnt/sdb/base $ btrfs send -f /tmp/base.snap /mnt/sdb/base $ xfs_io -c "fpunch 0 500K" /mnt/sdb/foobar $ btrfs subvolume snapshot -r /mnt/sdb /mnt/sdb/incr $ btrfs send -p /mnt/sdb/base -f /tmp/incr.snap /mnt/sdb/incr $ md5sum /mnt/sdb/incr/foobar 816df6f64deba63b029ca19d880ee10a /mnt/sdb/incr/foobar $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt/sdc $ btrfs receive -f /tmp/base.snap /mnt/sdc $ btrfs receive -f /tmp/incr.snap /mnt/sdc $ md5sum /mnt/sdc/incr/foobar cf2ef71f4a9e90c2f6013ba3b2257ed2 /mnt/sdc/incr/foobar --> Different checksum, because the prealloc extent beyond the file's eof confused the hole detection code and it assumed a hole starting at offset 0 and ending at the offset of the prealloc extent (1200Kb) instead of ending at the offset 500Kb (the file's size). Fix this by ensuring we never cross the file's size when issuing the write operations for a hole. Fixes: 16e7549f045d33 ("Btrfs: incompatible format change to remove hole extents") CC: stable@vger.kernel.org # 3.14+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-12Btrfs: fix fsync not persisting changed attributes of a directoryFilipe Manana
commit 60d9f50308e5df19bc18c2fefab0eba4a843900a upstream. While logging an inode we follow its ancestors and for each one we mark it as logged in the current transaction, even if we have not logged it. As a consequence if we change an attribute of an ancestor, such as the UID or GID for example, and then explicitly fsync it, we end up not logging the inode at all despite returning success to user space, which results in the attribute being lost if a power failure happens after the fsync. Sample reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ chown 6007:6007 /mnt/dir $ sync $ chown 9003:9003 /mnt/dir $ touch /mnt/dir/file $ xfs_io -c fsync /mnt/dir/file # fsync our directory after fsync'ing the new file, should persist the # new values for the uid and gid. $ xfs_io -c fsync /mnt/dir <power failure> $ mount /dev/sdb /mnt $ stat -c %u:%g /mnt/dir 6007:6007 --> should be 9003:9003, the uid and gid were not persisted, despite the explicit fsync on the directory prior to the power failure Fix this by not updating the logged_trans field of ancestor inodes when logging an inode, since we have not logged them. Let only future calls to btrfs_log_inode() to mark inodes as logged. This could be triggered by my recent fsync fuzz tester for fstests, for which an fstests patch exists titled "fstests: generic, fsync fuzz tester with fsstress". Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-12Btrfs: fix race updating log root item during fsyncFilipe Manana
commit 06989c799f04810f6876900d4760c0edda369cf7 upstream. When syncing the log, the final phase of a fsync operation, we need to either create a log root's item or update the existing item in the log tree of log roots, and that depends on the current value of the log root's log_transid - if it's 1 we need to create the log root item, otherwise it must exist already and we update it. Since there is no synchronization between updating the log_transid and checking it for deciding whether the log root's item needs to be created or updated, we end up with a tiny race window that results in attempts to update the item to fail because the item was not yet created: CPU 1 CPU 2 btrfs_sync_log() lock root->log_mutex set log root's log_transid to 1 unlock root->log_mutex btrfs_sync_log() lock root->log_mutex sets log root's log_transid to 2 unlock root->log_mutex update_log_root() sees log root's log_transid with a value of 2 calls btrfs_update_root(), which fails with -EUCLEAN and causes transaction abort Until recently the race lead to a BUG_ON at btrfs_update_root(), but after the recent commit 7ac1e464c4d47 ("btrfs: Don't panic when we can't find a root key") we just abort the current transaction. A sample trace of the BUG_ON() on a SLE12 kernel: ------------[ cut here ]------------ kernel BUG at ../fs/btrfs/root-tree.c:157! Oops: Exception in kernel mode, sig: 5 [#1] SMP NR_CPUS=2048 NUMA pSeries (...) Supported: Yes, External CPU: 78 PID: 76303 Comm: rtas_errd Tainted: G X 4.4.156-94.57-default #1 task: c00000ffa906d010 ti: c00000ff42b08000 task.ti: c00000ff42b08000 NIP: d000000036ae5cdc LR: d000000036ae5cd8 CTR: 0000000000000000 REGS: c00000ff42b0b860 TRAP: 0700 Tainted: G X (4.4.156-94.57-default) MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 22444484 XER: 20000000 CFAR: d000000036aba66c SOFTE: 1 GPR00: d000000036ae5cd8 c00000ff42b0bae0 d000000036bda220 0000000000000054 GPR04: 0000000000000001 0000000000000000 c00007ffff8d37c8 0000000000000000 GPR08: c000000000e19c00 0000000000000000 0000000000000000 3736343438312079 GPR12: 3930373337303434 c000000007a3a800 00000000007fffff 0000000000000023 GPR16: c00000ffa9d26028 c00000ffa9d261f8 0000000000000010 c00000ffa9d2ab28 GPR20: c00000ff42b0bc48 0000000000000001 c00000ff9f0d9888 0000000000000001 GPR24: c00000ffa9d26000 c00000ffa9d261e8 c00000ffa9d2a800 c00000ff9f0d9888 GPR28: c00000ffa9d26028 c00000ffa9d2aa98 0000000000000001 c00000ffa98f5b20 NIP [d000000036ae5cdc] btrfs_update_root+0x25c/0x4e0 [btrfs] LR [d000000036ae5cd8] btrfs_update_root+0x258/0x4e0 [btrfs] Call Trace: [c00000ff42b0bae0] [d000000036ae5cd8] btrfs_update_root+0x258/0x4e0 [btrfs] (unreliable) [c00000ff42b0bba0] [d000000036b53610] btrfs_sync_log+0x2d0/0xc60 [btrfs] [c00000ff42b0bce0] [d000000036b1785c] btrfs_sync_file+0x44c/0x4e0 [btrfs] [c00000ff42b0bd80] [c00000000032e300] vfs_fsync_range+0x70/0x120 [c00000ff42b0bdd0] [c00000000032e44c] do_fsync+0x5c/0xb0 [c00000ff42b0be10] [c00000000032e8dc] SyS_fdatasync+0x2c/0x40 [c00000ff42b0be30] [c000000000009488] system_call+0x3c/0x100 Instruction dump: 7f43d378 4bffebb9 60000000 88d90008 3d220000 e8b90000 3b390009 e87a01f0 e8898e08 e8f90000 4bfd48e5 60000000 <0fe00000> e95b0060 39200004 394a0ea0 ---[ end trace 8f2dc8f919cabab8 ]--- So fix this by doing the check of log_transid and updating or creating the log root's item while holding the root's log_mutex. Fixes: 7237f1833601d ("Btrfs: fix tree logs parallel sync") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-12Btrfs: fix wrong ctime and mtime of a directory after log replayFilipe Manana
commit 5338e43abbab13791144d37fd8846847062351c6 upstream. When replaying a log that contains a new file or directory name that needs to be added to its parent directory, we end up updating the mtime and the ctime of the parent directory to the current time after we have set their values to the correct ones (set at fsync time), efectivelly losing them. Sample reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/file # fsync of the directory is optional, not needed $ xfs_io -c fsync /mnt/dir $ xfs_io -c fsync /mnt/dir/file $ stat -c %Y /mnt/dir 1557856079 <power failure> $ sleep 3 $ mount /dev/sdb /mnt $ stat -c %Y /mnt/dir 1557856082 --> should have been 1557856079, the mtime is updated to the current time when replaying the log Fix this by not updating the mtime and ctime to the current time at btrfs_add_link() when we are replaying a log tree. This could be triggered by my recent fsync fuzz tester for fstests, for which an fstests patch exists titled "fstests: generic, fsync fuzz tester with fsstress". Fixes: e02119d5a7b43 ("Btrfs: Add a write ahead tree log to optimize synchronous operations") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-02btrfs: Don't panic when we can't find a root keyQu Wenruo
commit 7ac1e464c4d473b517bb784f30d40da1f842482e upstream. When we failed to find a root key in btrfs_update_root(), we just panic. That's definitely not cool, fix it by outputting an unique error message, aborting current transaction and return -EUCLEAN. This should not normally happen as the root has been used by the callers in some way. Reviewed-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-02btrfs: fix panic during relocation after ENOSPC before writeback happensJosef Bacik
commit ff612ba7849964b1898fd3ccd1f56941129c6aab upstream. We've been seeing the following sporadically throughout our fleet panic: kernel BUG at fs/btrfs/relocation.c:4584! netversion: 5.0-0 Backtrace: #0 [ffffc90003adb880] machine_kexec at ffffffff81041da8 #1 [ffffc90003adb8c8] __crash_kexec at ffffffff8110396c #2 [ffffc90003adb988] crash_kexec at ffffffff811048ad #3 [ffffc90003adb9a0] oops_end at ffffffff8101c19a #4 [ffffc90003adb9c0] do_trap at ffffffff81019114 #5 [ffffc90003adba00] do_error_trap at ffffffff810195d0 #6 [ffffc90003adbab0] invalid_op at ffffffff81a00a9b [exception RIP: btrfs_reloc_cow_block+692] RIP: ffffffff8143b614 RSP: ffffc90003adbb68 RFLAGS: 00010246 RAX: fffffffffffffff7 RBX: ffff8806b9c32000 RCX: ffff8806aad00690 RDX: ffff880850b295e0 RSI: ffff8806b9c32000 RDI: ffff88084f205bd0 RBP: ffff880849415000 R8: ffffc90003adbbe0 R9: ffff88085ac90000 R10: ffff8805f7369140 R11: 0000000000000000 R12: ffff880850b295e0 R13: ffff88084f205bd0 R14: 0000000000000000 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffffc90003adbbb0] __btrfs_cow_block at ffffffff813bf1cd #8 [ffffc90003adbc28] btrfs_cow_block at ffffffff813bf4b3 #9 [ffffc90003adbc78] btrfs_search_slot at ffffffff813c2e6c The way relocation moves data extents is by creating a reloc inode and preallocating extents in this inode and then copying the data into these preallocated extents. Once we've done this for all of our extents, we'll write out these dirty pages, which marks the extent written, and goes into btrfs_reloc_cow_block(). From here we get our current reloc_control, which _should_ match the reloc_control for the current block group we're relocating. However if we get an ENOSPC in this path at some point we'll bail out, never initiating writeback on this inode. Not a huge deal, unless we happen to be doing relocation on a different block group, and this block group is now rc->stage == UPDATE_DATA_PTRS. This trips the BUG_ON() in btrfs_reloc_cow_block(), because we expect to be done modifying the data inode. We are in fact done modifying the metadata for the data inode we're currently using, but not the one from the failed block group, and thus we BUG_ON(). (This happens when writeback finishes for extents from the previous group, when we are at btrfs_finish_ordered_io() which updates the data reloc tree (inode item, drops/adds extent items, etc).) Fix this by writing out the reloc data inode always, and then breaking out of the loop after that point to keep from tripping this BUG_ON() later. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> [ add note from Filipe ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-02Btrfs: fix data bytes_may_use underflow with fallocate due to failed quota ↵Robbie Ko
reserve commit 39ad317315887c2cb9a4347a93a8859326ddf136 upstream. When doing fallocate, we first add the range to the reserve_list and then reserve the quota. If quota reservation fails, we'll release all reserved parts of reserve_list. However, cur_offset is not updated to indicate that this range is already been inserted into the list. Therefore, the same range is freed twice. Once at list_for_each_entry loop, and once at the end of the function. This will result in WARN_ON on bytes_may_use when we free the remaining space. At the end, under the 'out' label we have a call to: btrfs_free_reserved_data_space(inode, data_reserved, alloc_start, alloc_end - cur_offset); The start offset, third argument, should be cur_offset. Everything from alloc_start to cur_offset was freed by the list_for_each_entry_safe_loop. Fixes: 18513091af94 ("btrfs: update btrfs_space_info's bytes_may_use timely") Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Robbie Ko <robbieko@synology.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-02btrfs: sysfs: don't leak memory when failing add fsidTobin C. Harding
commit e32773357d5cc271b1d23550b3ed026eb5c2a468 upstream. A failed call to kobject_init_and_add() must be followed by a call to kobject_put(). Currently in the error path when adding fs_devices we are missing this call. This could be fixed by calling btrfs_sysfs_remove_fsid() if btrfs_sysfs_add_fsid() returns an error or by adding a call to kobject_put() directly in btrfs_sysfs_add_fsid(). Here we choose the second option because it prevents the slightly unusual error path handling requirements of kobject from leaking out into btrfs functions. Add a call to kobject_put() in the error path of kobject_add_and_init(). This causes the release method to be called if kobject_init_and_add() fails. open_tree() is the function that calls btrfs_sysfs_add_fsid() and the error code in this function is already written with the assumption that the release method is called during the error path of open_tree() (as seen by the call to btrfs_sysfs_remove_fsid() under the fail_fsdev_sysfs label). Cc: stable@vger.kernel.org # v4.4+ Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tobin C. Harding <tobin@kernel.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-02btrfs: sysfs: Fix error path kobject memory leakTobin C. Harding
commit 450ff8348808a89cc27436771aa05c2b90c0eef1 upstream. If a call to kobject_init_and_add() fails we must call kobject_put() otherwise we leak memory. Calling kobject_put() when kobject_init_and_add() fails drops the refcount back to 0 and calls the ktype release method (which in turn calls the percpu destroy and kfree). Add call to kobject_put() in the error path of call to kobject_init_and_add(). Cc: stable@vger.kernel.org # v4.4+ Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tobin C. Harding <tobin@kernel.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-02Btrfs: fix race between ranged fsync and writeback of adjacent rangesFilipe Manana
commit 0c713cbab6200b0ab6473b50435e450a6e1de85d upstream. When we do a full fsync (the bit BTRFS_INODE_NEEDS_FULL_SYNC is set in the inode) that happens to be ranged, which happens during a msync() or writes for files opened with O_SYNC for example, we can end up with a corrupt log, due to different file extent items representing ranges that overlap with each other, or hit some assertion failures. When doing a ranged fsync we only flush delalloc and wait for ordered exents within that range. If while we are logging items from our inode ordered extents for adjacent ranges complete, we end up in a race that can make us insert the file extent items that overlap with others we logged previously and the assertion failures. For example, if tree-log.c:copy_items() receives a leaf that has the following file extents items, all with a length of 4K and therefore there is an implicit hole in the range 68K to 72K - 1: (257 EXTENT_ITEM 64K), (257 EXTENT_ITEM 72K), (257 EXTENT_ITEM 76K), ... It copies them to the log tree. However due to the need to detect implicit holes, it may release the path, in order to look at the previous leaf to detect an implicit hole, and then later it will search again in the tree for the first file extent item key, with the goal of locking again the leaf (which might have changed due to concurrent changes to other inodes). However when it locks again the leaf containing the first key, the key corresponding to the extent at offset 72K may not be there anymore since there is an ordered extent for that range that is finishing (that is, somewhere in the middle of btrfs_finish_ordered_io()), and it just removed the file extent item but has not yet replaced it with a new file extent item, so the part of copy_items() that does hole detection will decide that there is a hole in the range starting from 68K to 76K - 1, and therefore insert a file extent item to represent that hole, having a key offset of 68K. After that we now have a log tree with 2 different extent items that have overlapping ranges: 1) The file extent item copied before copy_items() released the path, which has a key offset of 72K and a length of 4K, representing the file range 72K to 76K - 1. 2) And a file extent item representing a hole that has a key offset of 68K and a length of 8K, representing the range 68K to 76K - 1. This item was inserted after releasing the path, and overlaps with the extent item inserted before. The overlapping extent items can cause all sorts of unpredictable and incorrect behaviour, either when replayed or if a fast (non full) fsync happens later, which can trigger a BUG_ON() when calling btrfs_set_item_key_safe() through __btrfs_drop_extents(), producing a trace like the following: [61666.783269] ------------[ cut here ]------------ [61666.783943] kernel BUG at fs/btrfs/ctree.c:3182! [61666.784644] invalid opcode: 0000 [#1] PREEMPT SMP (...) [61666.786253] task: ffff880117b88c40 task.stack: ffffc90008168000 [61666.786253] RIP: 0010:btrfs_set_item_key_safe+0x7c/0xd2 [btrfs] [61666.786253] RSP: 0018:ffffc9000816b958 EFLAGS: 00010246 [61666.786253] RAX: 0000000000000000 RBX: 000000000000000f RCX: 0000000000030000 [61666.786253] RDX: 0000000000000000 RSI: ffffc9000816ba4f RDI: ffffc9000816b937 [61666.786253] RBP: ffffc9000816b998 R08: ffff88011dae2428 R09: 0000000000001000 [61666.786253] R10: 0000160000000000 R11: 6db6db6db6db6db7 R12: ffff88011dae2418 [61666.786253] R13: ffffc9000816ba4f R14: ffff8801e10c4118 R15: ffff8801e715c000 [61666.786253] FS: 00007f6060a18700(0000) GS:ffff88023f5c0000(0000) knlGS:0000000000000000 [61666.786253] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [61666.786253] CR2: 00007f6060a28000 CR3: 0000000213e69000 CR4: 00000000000006e0 [61666.786253] Call Trace: [61666.786253] __btrfs_drop_extents+0x5e3/0xaad [btrfs] [61666.786253] ? time_hardirqs_on+0x9/0x14 [61666.786253] btrfs_log_changed_extents+0x294/0x4e0 [btrfs] [61666.786253] ? release_extent_buffer+0x38/0xb4 [btrfs] [61666.786253] btrfs_log_inode+0xb6e/0xcdc [btrfs] [61666.786253] ? lock_acquire+0x131/0x1c5 [61666.786253] ? btrfs_log_inode_parent+0xee/0x659 [btrfs] [61666.786253] ? arch_local_irq_save+0x9/0xc [61666.786253] ? btrfs_log_inode_parent+0x1f5/0x659 [btrfs] [61666.786253] btrfs_log_inode_parent+0x223/0x659 [btrfs] [61666.786253] ? arch_local_irq_save+0x9/0xc [61666.786253] ? lockref_get_not_zero+0x2c/0x34 [61666.786253] ? rcu_read_unlock+0x3e/0x5d [61666.786253] btrfs_log_dentry_safe+0x60/0x7b [btrfs] [61666.786253] btrfs_sync_file+0x317/0x42c [btrfs] [61666.786253] vfs_fsync_range+0x8c/0x9e [61666.786253] SyS_msync+0x13c/0x1c9 [61666.786253] entry_SYSCALL_64_fastpath+0x18/0xad A sample of a corrupt log tree leaf with overlapping extents I got from running btrfs/072: item 14 key (295 108 200704) itemoff 2599 itemsize 53 extent data disk bytenr 0 nr 0 extent data offset 0 nr 458752 ram 458752 item 15 key (295 108 659456) itemoff 2546 itemsize 53 extent data disk bytenr 4343541760 nr 770048 extent data offset 606208 nr 163840 ram 770048 item 16 key (295 108 663552) itemoff 2493 itemsize 53 extent data disk bytenr 4343541760 nr 770048 extent data offset 610304 nr 155648 ram 770048 item 17 key (295 108 819200) itemoff 2440 itemsize 53 extent data disk bytenr 4334788608 nr 4096 extent data offset 0 nr 4096 ram 4096 The file extent item at offset 659456 (item 15) ends at offset 823296 (659456 + 163840) while the next file extent item (item 16) starts at offset 663552. Another different problem that the race can trigger is a failure in the assertions at tree-log.c:copy_items(), which expect that the first file extent item key we found before releasing the path exists after we have released path and that the last key we found before releasing the path also exists after releasing the path: $ cat -n fs/btrfs/tree-log.c 4080 if (need_find_last_extent) { 4081 /* btrfs_prev_leaf could return 1 without releasing the path */ 4082 btrfs_release_path(src_path); 4083 ret = btrfs_search_slot(NULL, inode->root, &first_key, 4084 src_path, 0, 0); 4085 if (ret < 0) 4086 return ret; 4087 ASSERT(ret == 0); (...) 4103 if (i >= btrfs_header_nritems(src_path->nodes[0])) { 4104 ret = btrfs_next_leaf(inode->root, src_path); 4105 if (ret < 0) 4106 return ret; 4107 ASSERT(ret == 0); 4108 src = src_path->nodes[0]; 4109 i = 0; 4110 need_find_last_extent = true; 4111 } (...) The second assertion implicitly expects that the last key before the path release still exists, because the surrounding while loop only stops after we have found that key. When this assertion fails it produces a stack like this: [139590.037075] assertion failed: ret == 0, file: fs/btrfs/tree-log.c, line: 4107 [139590.037406] ------------[ cut here ]------------ [139590.037707] kernel BUG at fs/btrfs/ctree.h:3546! [139590.038034] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI [139590.038340] CPU: 1 PID: 31841 Comm: fsstress Tainted: G W 5.0.0-btrfs-next-46 #1 (...) [139590.039354] RIP: 0010:assfail.constprop.24+0x18/0x1a [btrfs] (...) [139590.040397] RSP: 0018:ffffa27f48f2b9b0 EFLAGS: 00010282 [139590.040730] RAX: 0000000000000041 RBX: ffff897c635d92c8 RCX: 0000000000000000 [139590.041105] RDX: 0000000000000000 RSI: ffff897d36a96868 RDI: ffff897d36a96868 [139590.041470] RBP: ffff897d1b9a0708 R08: 0000000000000000 R09: 0000000000000000 [139590.041815] R10: 0000000000000008 R11: 0000000000000000 R12: 0000000000000013 [139590.042159] R13: 0000000000000227 R14: ffff897cffcbba88 R15: 0000000000000001 [139590.042501] FS: 00007f2efc8dee80(0000) GS:ffff897d36a80000(0000) knlGS:0000000000000000 [139590.042847] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [139590.043199] CR2: 00007f8c064935e0 CR3: 0000000232252002 CR4: 00000000003606e0 [139590.043547] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [139590.043899] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [139590.044250] Call Trace: [139590.044631] copy_items+0xa3f/0x1000 [btrfs] [139590.045009] ? generic_bin_search.constprop.32+0x61/0x200 [btrfs] [139590.045396] btrfs_log_inode+0x7b3/0xd70 [btrfs] [139590.045773] btrfs_log_inode_parent+0x2b3/0xce0 [btrfs] [139590.046143] ? do_raw_spin_unlock+0x49/0xc0 [139590.046510] btrfs_log_dentry_safe+0x4a/0x70 [btrfs] [139590.046872] btrfs_sync_file+0x3b6/0x440 [btrfs] [139590.047243] btrfs_file_write_iter+0x45b/0x5c0 [btrfs] [139590.047592] __vfs_write+0x129/0x1c0 [139590.047932] vfs_write+0xc2/0x1b0 [139590.048270] ksys_write+0x55/0xc0 [139590.048608] do_syscall_64+0x60/0x1b0 [139590.048946] entry_SYSCALL_64_after_hwframe+0x49/0xbe [139590.049287] RIP: 0033:0x7f2efc4be190 (...) [139590.050342] RSP: 002b:00007ffe743243a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [139590.050701] RAX: ffffffffffffffda RBX: 0000000000008d58 RCX: 00007f2efc4be190 [139590.051067] RDX: 0000000000008d58 RSI: 00005567eca0f370 RDI: 0000000000000003 [139590.051459] RBP: 0000000000000024 R08: 0000000000000003 R09: 0000000000008d60 [139590.051863] R10: 0000000000000078 R11: 0000000000000246 R12: 0000000000000003 [139590.052252] R13: 00000000003d3507 R14: 00005567eca0f370 R15: 0000000000000000 (...) [139590.055128] ---[ end trace 193f35d0215cdeeb ]--- So fix this race between a full ranged fsync and writeback of adjacent ranges by flushing all delalloc and waiting for all ordered extents to complete before logging the inode. This is the simplest way to solve the problem because currently the full fsync path does not deal with ranges at all (it assumes a full range from 0 to LLONG_MAX) and it always needs to look at adjacent ranges for hole detection. For use cases of ranged fsyncs this can make a few fsyncs slower but on the other hand it can make some following fsyncs to other ranges do less work or no need to do anything at all. A full fsync is rare anyway and happens only once after loading/creating an inode and once after less common operations such as a shrinking truncate. This is an issue that exists for a long time, and was often triggered by generic/127, because it does mmap'ed writes and msync (which triggers a ranged fsync). Adding support for the tree checker to detect overlapping extents (next patch in the series) and trigger a WARN() when such cases are found, and then calling btrfs_check_leaf_full() at the end of btrfs_insert_file_extent() made the issue much easier to detect. Running btrfs/072 with that change to the tree checker and making fsstress open files always with O_SYNC made it much easier to trigger the issue (as triggering it with generic/127 is very rare). CC: stable@vger.kernel.org # 3.16+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-02Btrfs: avoid fallback to transaction commit during fsync of files with holesFilipe Manana
commit ebb929060aeb162417b4c1307e63daee47b208d9 upstream. When we are doing a full fsync (bit BTRFS_INODE_NEEDS_FULL_SYNC set) of a file that has holes and has file extent items spanning two or more leafs, we can end up falling to back to a full transaction commit due to a logic bug that leads to failure to insert a duplicate file extent item that is meant to represent a hole between the last file extent item of a leaf and the first file extent item in the next leaf. The failure (EEXIST error) leads to a transaction commit (as most errors when logging an inode do). For example, we have the two following leafs: Leaf N: ----------------------------------------------- | ..., ..., ..., (257, FILE_EXTENT_ITEM, 64K) | ----------------------------------------------- The file extent item at the end of leaf N has a length of 4Kb, representing the file range from 64K to 68K - 1. Leaf N + 1: ----------------------------------------------- | (257, FILE_EXTENT_ITEM, 72K), ..., ..., ... | ----------------------------------------------- The file extent item at the first slot of leaf N + 1 has a length of 4Kb too, representing the file range from 72K to 76K - 1. During the full fsync path, when we are at tree-log.c:copy_items() with leaf N as a parameter, after processing the last file extent item, that represents the extent at offset 64K, we take a look at the first file extent item at the next leaf (leaf N + 1), and notice there's a 4K hole between the two extents, and therefore we insert a file extent item representing that hole, starting at file offset 68K and ending at offset 72K - 1. However we don't update the value of *last_extent, which is used to represent the end offset (plus 1, non-inclusive end) of the last file extent item inserted in the log, so it stays with a value of 68K and not with a value of 72K. Then, when copy_items() is called for leaf N + 1, because the value of *last_extent is smaller then the offset of the first extent item in the leaf (68K < 72K), we look at the last file extent item in the previous leaf (leaf N) and see it there's a 4K gap between it and our first file extent item (again, 68K < 72K), so we decide to insert a file extent item representing the hole, starting at file offset 68K and ending at offset 72K - 1, this insertion will fail with -EEXIST being returned from btrfs_insert_file_extent() because we already inserted a file extent item representing a hole for this offset (68K) in the previous call to copy_items(), when processing leaf N. The -EEXIST error gets propagated to the fsync callback, btrfs_sync_file(), which falls back to a full transaction commit. Fix this by adjusting *last_extent after inserting a hole when we had to look at the next leaf. Fixes: 4ee3fad34a9c ("Btrfs: fix fsync after hole punching when using no-holes feature") Cc: stable@vger.kernel.org # 4.14+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-02Btrfs: do not abort transaction at btrfs_update_root() after failure to COW pathFilipe Manana
commit 72bd2323ec87722c115a5906bc6a1b31d11e8f54 upstream. Currently when we fail to COW a path at btrfs_update_root() we end up always aborting the transaction. However all the current callers of btrfs_update_root() are able to deal with errors returned from it, many do end up aborting the transaction themselves (directly or not, such as the transaction commit path), other BUG_ON() or just gracefully cancel whatever they were doing. When syncing the fsync log, we call btrfs_update_root() through tree-log.c:update_log_root(), and if it returns an -ENOSPC error, the log sync code does not abort the transaction, instead it gracefully handles the error and returns -EAGAIN to the fsync handler, so that it falls back to a transaction commit. Any other error different from -ENOSPC, makes the log sync code abort the transaction. So remove the transaction abort from btrfs_update_log() when we fail to COW a path to update the root item, so that if an -ENOSPC failure happens we avoid aborting the current transaction and have a chance of the fsync succeeding after falling back to a transaction commit. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203413 Fixes: 79787eaab46121 ("btrfs: replace many BUG_ONs with proper error handling") Cc: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-02Revert "btrfs: Honour FITRIM range constraints during free space trim"Paul Gortmaker
This reverts commit bdc4fc32478fec8cd3a9e2a60c06e287ffee042c. Following the revert found in 4.19.47, which says: From: David Sterba <dsterba@suse.com> There is currently no corresponding patch in master due to additional changes that would be significantly different from plain revert in the respective stable branch. The range argument was not handled correctly and could cause trim to overlap allocated areas or reach beyond the end of the device. The address space that fitrim normally operates on is in logical coordinates, while the discards are done on the physical device extents. This distinction cannot be made with the current ioctl interface and caused the confusion. The bug depends on the layout of block groups and does not always happen. The whole-fs trim (run by default by the fstrim tool) is not affected. Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30Btrfs: do not start a transaction at iterate_extent_inodes()Filipe Manana
commit bfc61c36260ca990937539cd648ede3cd749bc10 upstream. When finding out which inodes have references on a particular extent, done by backref.c:iterate_extent_inodes(), from the BTRFS_IOC_LOGICAL_INO (both v1 and v2) ioctl and from scrub we use the transaction join API to grab a reference on the currently running transaction, since in order to give accurate results we need to inspect the delayed references of the currently running transaction. However, if there is currently no running transaction, the join operation will create a new transaction. This is inefficient as the transaction will eventually be committed, doing unnecessary IO and introducing a potential point of failure that will lead to a transaction abort due to -ENOSPC, as recently reported [1]. That's because the join, creates the transaction but does not reserve any space, so when attempting to update the root item of the root passed to btrfs_join_transaction(), during the transaction commit, we can end up failling with -ENOSPC. Users of a join operation are supposed to actually do some filesystem changes and reserve space by some means, which is not the case of iterate_extent_inodes(), it is a read-only operation for all contextes from which it is called. The reported [1] -ENOSPC failure stack trace is the following: heisenberg kernel: ------------[ cut here ]------------ heisenberg kernel: BTRFS: Transaction aborted (error -28) heisenberg kernel: WARNING: CPU: 0 PID: 7137 at fs/btrfs/root-tree.c:136 btrfs_update_root+0x22b/0x320 [btrfs] (...) heisenberg kernel: CPU: 0 PID: 7137 Comm: btrfs-transacti Not tainted 4.19.0-4-amd64 #1 Debian 4.19.28-2 heisenberg kernel: Hardware name: FUJITSU LIFEBOOK U757/FJNB2A5, BIOS Version 1.21 03/19/2018 heisenberg kernel: RIP: 0010:btrfs_update_root+0x22b/0x320 [btrfs] (...) heisenberg kernel: RSP: 0018:ffffb5448828bd40 EFLAGS: 00010286 heisenberg kernel: RAX: 0000000000000000 RBX: ffff8ed56bccef50 RCX: 0000000000000006 heisenberg kernel: RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff8ed6bda166a0 heisenberg kernel: RBP: 00000000ffffffe4 R08: 00000000000003df R09: 0000000000000007 heisenberg kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff8ed63396a078 heisenberg kernel: R13: ffff8ed092d7c800 R14: ffff8ed64f5db028 R15: ffff8ed6bd03d068 heisenberg kernel: FS: 0000000000000000(0000) GS:ffff8ed6bda00000(0000) knlGS:0000000000000000 heisenberg kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 heisenberg kernel: CR2: 00007f46f75f8000 CR3: 0000000310a0a002 CR4: 00000000003606f0 heisenberg kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 heisenberg kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 heisenberg kernel: Call Trace: heisenberg kernel: commit_fs_roots+0x166/0x1d0 [btrfs] heisenberg kernel: ? _cond_resched+0x15/0x30 heisenberg kernel: ? btrfs_run_delayed_refs+0xac/0x180 [btrfs] heisenberg kernel: btrfs_commit_transaction+0x2bd/0x870 [btrfs] heisenberg kernel: ? start_transaction+0x9d/0x3f0 [btrfs] heisenberg kernel: transaction_kthread+0x147/0x180 [btrfs] heisenberg kernel: ? btrfs_cleanup_transaction+0x530/0x530 [btrfs] heisenberg kernel: kthread+0x112/0x130 heisenberg kernel: ? kthread_bind+0x30/0x30 heisenberg kernel: ret_from_fork+0x35/0x40 heisenberg kernel: ---[ end trace 05de912e30e012d9 ]--- So fix that by using the attach API, which does not create a transaction when there is currently no running transaction. [1] https://lore.kernel.org/linux-btrfs/b2a668d7124f1d3e410367f587926f622b3f03a4.camel@scientia.net/ Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30Btrfs: do not start a transaction during fiemapFilipe Manana
commit 03628cdbc64db6262e50d0357960a4e9562676a1 upstream. During fiemap, for regular extents (non inline) we need to check if they are shared and if they are, set the shared bit. Checking if an extent is shared requires checking the delayed references of the currently running transaction, since some reference might have not yet hit the extent tree and be only in the in-memory delayed references. However we were using a transaction join for this, which creates a new transaction when there is no transaction currently running. That means that two more potential failures can happen: creating the transaction and committing it. Further, if no write activity is currently happening in the system, and fiemap calls keep being done, we end up creating and committing transactions that do nothing. In some extreme cases this can result in the commit of the transaction created by fiemap to fail with ENOSPC when updating the root item of a subvolume tree because a join does not reserve any space, leading to a trace like the following: heisenberg kernel: ------------[ cut here ]------------ heisenberg kernel: BTRFS: Transaction aborted (error -28) heisenberg kernel: WARNING: CPU: 0 PID: 7137 at fs/btrfs/root-tree.c:136 btrfs_update_root+0x22b/0x320 [btrfs] (...) heisenberg kernel: CPU: 0 PID: 7137 Comm: btrfs-transacti Not tainted 4.19.0-4-amd64 #1 Debian 4.19.28-2 heisenberg kernel: Hardware name: FUJITSU LIFEBOOK U757/FJNB2A5, BIOS Version 1.21 03/19/2018 heisenberg kernel: RIP: 0010:btrfs_update_root+0x22b/0x320 [btrfs] (...) heisenberg kernel: RSP: 0018:ffffb5448828bd40 EFLAGS: 00010286 heisenberg kernel: RAX: 0000000000000000 RBX: ffff8ed56bccef50 RCX: 0000000000000006 heisenberg kernel: RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff8ed6bda166a0 heisenberg kernel: RBP: 00000000ffffffe4 R08: 00000000000003df R09: 0000000000000007 heisenberg kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff8ed63396a078 heisenberg kernel: R13: ffff8ed092d7c800 R14: ffff8ed64f5db028 R15: ffff8ed6bd03d068 heisenberg kernel: FS: 0000000000000000(0000) GS:ffff8ed6bda00000(0000) knlGS:0000000000000000 heisenberg kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 heisenberg kernel: CR2: 00007f46f75f8000 CR3: 0000000310a0a002 CR4: 00000000003606f0 heisenberg kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 heisenberg kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 heisenberg kernel: Call Trace: heisenberg kernel: commit_fs_roots+0x166/0x1d0 [btrfs] heisenberg kernel: ? _cond_resched+0x15/0x30 heisenberg kernel: ? btrfs_run_delayed_refs+0xac/0x180 [btrfs] heisenberg kernel: btrfs_commit_transaction+0x2bd/0x870 [btrfs] heisenberg kernel: ? start_transaction+0x9d/0x3f0 [btrfs] heisenberg kernel: transaction_kthread+0x147/0x180 [btrfs] heisenberg kernel: ? btrfs_cleanup_transaction+0x530/0x530 [btrfs] heisenberg kernel: kthread+0x112/0x130 heisenberg kernel: ? kthread_bind+0x30/0x30 heisenberg kernel: ret_from_fork+0x35/0x40 heisenberg kernel: ---[ end trace 05de912e30e012d9 ]--- Since fiemap (and btrfs_check_shared()) is a read-only operation, do not do a transaction join to avoid the overhead of creating a new transaction (if there is currently no running transaction) and introducing a potential point of failure when the new transaction gets committed, instead use a transaction attach to grab a handle for the currently running transaction if any. Reported-by: Christoph Anton Mitterer <calestyo@scientia.net> Link: https://lore.kernel.org/linux-btrfs/b2a668d7124f1d3e410367f587926f622b3f03a4.camel@scientia.net/ Fixes: afce772e87c36c ("btrfs: fix check_shared for fiemap ioctl") CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30Btrfs: send, flush dellaloc in order to avoid data lossFilipe Manana
commit 9f89d5de8631c7930898a601b6612e271aa2261c upstream. When we set a subvolume to read-only mode we do not flush dellaloc for any of its inodes (except if the filesystem is mounted with -o flushoncommit), since it does not affect correctness for any subsequent operations - except for a future send operation. The send operation will not be able to see the delalloc data since the respective file extent items, inode item updates, backreferences, etc, have not hit yet the subvolume and extent trees. Effectively this means data loss, since the send stream will not contain any data from existing delalloc. Another problem from this is that if the writeback starts and finishes while the send operation is in progress, we have the subvolume tree being being modified concurrently which can result in send failing unexpectedly with EIO or hitting runtime errors, assertion failures or hitting BUG_ONs, etc. Simple reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ btrfs subvolume create /mnt/sv $ xfs_io -f -c "pwrite -S 0xea 0 108K" /mnt/sv/foo $ btrfs property set /mnt/sv ro true $ btrfs send -f /tmp/send.stream /mnt/sv $ od -t x1 -A d /mnt/sv/foo 0000000 ea ea ea ea ea ea ea ea ea ea ea ea ea ea ea ea * 0110592 $ umount /mnt $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ btrfs receive -f /tmp/send.stream /mnt $ echo $? 0 $ od -t x1 -A d /mnt/sv/foo 0000000 # ---> empty file Since this a problem that affects send only, fix it in send by flushing dellaloc for all the roots used by the send operation before send starts to process the commit roots. This is a problem that affects send since it was introduced (commit 31db9f7c23fbf7 ("Btrfs: introduce BTRFS_IOC_SEND for btrfs send/receive")) but backporting it to older kernels has some dependencies: - For kernels between 3.19 and 4.20, it depends on commit 3cd24c698004d2 ("btrfs: use tagged writepage to mitigate livelock of snapshot") because the function btrfs_start_delalloc_snapshot() does not exist before that commit. So one has to either pick that commit or replace the calls to btrfs_start_delalloc_snapshot() in this patch with calls to btrfs_start_delalloc_inodes(). - For kernels older than 3.19 it also requires commit e5fa8f865b3324 ("Btrfs: ensure send always works on roots without orphans") because it depends on the function ensure_commit_roots_uptodate() which that commits introduced. - No dependencies for 5.0+ kernels. A test case for fstests follows soon. CC: stable@vger.kernel.org # 3.19+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30btrfs: Honour FITRIM range constraints during free space trimNikolay Borisov
commit c2d1b3aae33605a61cbab445d8ae1c708ccd2698 upstream. Up until now trimming the freespace was done irrespective of what the arguments of the FITRIM ioctl were. For example fstrim's -o/-l arguments will be entirely ignored. Fix it by correctly handling those paramter. This requires breaking if the found freespace extent is after the end of the passed range as well as completing trim after trimming fstrim_range::len bytes. Fixes: 499f377f49f0 ("btrfs: iterate over unused chunk space in FITRIM") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30btrfs: Correctly free extent buffer in case btree_read_extent_buffer_pages failsNikolay Borisov
commit 537f38f019fa0b762dbb4c0fc95d7fcce9db8e2d upstream. If a an eb fails to be read for whatever reason - it's corrupted on disk and parent transid/key validations fail or IO for eb pages fail then this buffer must be removed from the buffer cache. Currently the code calls free_extent_buffer if an error occurs. Unfortunately this doesn't achieve the desired behavior since btrfs_find_create_tree_block returns with eb->refs == 2. On the other hand free_extent_buffer will only decrement the refs once leaving it added to the buffer cache radix tree. This enables later code to look up the buffer from the cache and utilize it potentially leading to a crash. The correct way to free the buffer is call free_extent_buffer_stale. This function will correctly call atomic_dec explicitly for the buffer and subsequently call release_extent_buffer which will decrement the final reference thus correctly remove the invalid buffer from buffer cache. This change affects only newly allocated buffers since they have eb->refs == 2. Link: https://bugzilla.kernel.org/show_bug.cgi?id=202755 Reported-by: Jungyeon <jungyeon@gatech.edu> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30btrfs: Check the first key and level for cached extent bufferQu Wenruo
commit 448de471cd4cab0cedd15770082567a69a784a11 upstream. [BUG] When reading a file from a fuzzed image, kernel can panic like: BTRFS warning (device loop0): csum failed root 5 ino 270 off 0 csum 0x98f94189 expected csum 0x00000000 mirror 1 assertion failed: !memcmp_extent_buffer(b, &disk_key, offsetof(struct btrfs_leaf, items[0].key), sizeof(disk_key)), file: fs/btrfs/ctree.c, line: 2544 ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.h:3500! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:btrfs_search_slot.cold.24+0x61/0x63 [btrfs] Call Trace: btrfs_lookup_csum+0x52/0x150 [btrfs] __btrfs_lookup_bio_sums+0x209/0x640 [btrfs] btrfs_submit_bio_hook+0x103/0x170 [btrfs] submit_one_bio+0x59/0x80 [btrfs] extent_read_full_page+0x58/0x80 [btrfs] generic_file_read_iter+0x2f6/0x9d0 __vfs_read+0x14d/0x1a0 vfs_read+0x8d/0x140 ksys_read+0x52/0xc0 do_syscall_64+0x60/0x210 entry_SYSCALL_64_after_hwframe+0x49/0xbe [CAUSE] The fuzzed image has a corrupted leaf whose first key doesn't match its parent: checksum tree key (CSUM_TREE ROOT_ITEM 0) node 29741056 level 1 items 14 free 107 generation 19 owner CSUM_TREE fs uuid 3381d111-94a3-4ac7-8f39-611bbbdab7e6 chunk uuid 9af1c3c7-2af5-488b-8553-530bd515f14c ... key (EXTENT_CSUM EXTENT_CSUM 79691776) block 29761536 gen 19 leaf 29761536 items 1 free space 1726 generation 19 owner CSUM_TREE leaf 29761536 flags 0x1(WRITTEN) backref revision 1 fs uuid 3381d111-94a3-4ac7-8f39-611bbbdab7e6 chunk uuid 9af1c3c7-2af5-488b-8553-530bd515f14c item 0 key (EXTENT_CSUM EXTENT_CSUM 8798638964736) itemoff 1751 itemsize 2244 range start 8798638964736 end 8798641262592 length 2297856 When reading the above tree block, we have extent_buffer->refs = 2 in the context: - initial one from __alloc_extent_buffer() alloc_extent_buffer() |- __alloc_extent_buffer() |- atomic_set(&eb->refs, 1) - one being added to fs_info->buffer_radix alloc_extent_buffer() |- check_buffer_tree_ref() |- atomic_inc(&eb->refs) So if even we call free_extent_buffer() in read_tree_block or other similar situation, we only decrease the refs by 1, it doesn't reach 0 and won't be freed right now. The staled eb and its corrupted content will still be kept cached. Furthermore, we have several extra cases where we either don't do first key check or the check is not proper for all callers: - scrub We just don't have first key in this context. - shared tree block One tree block can be shared by several snapshot/subvolume trees. In that case, the first key check for one subvolume doesn't apply to another. So for the above reasons, a corrupted extent buffer can sneak into the buffer cache. [FIX] Call verify_level_key in read_block_for_search to do another verification. For that purpose the function is exported. Due to above reasons, although we can free corrupted extent buffer from cache, we still need the check in read_block_for_search(), for scrub and shared tree blocks. Link: https://bugzilla.kernel.org/show_bug.cgi?id=202755 Link: https://bugzilla.kernel.org/show_bug.cgi?id=202757 Link: https://bugzilla.kernel.org/show_bug.cgi?id=202759 Link: https://bugzilla.kernel.org/show_bug.cgi?id=202761 Link: https://bugzilla.kernel.org/show_bug.cgi?id=202767 Link: https://bugzilla.kernel.org/show_bug.cgi?id=202769 Reported-by: Yoon Jungyeon <jungyeon@gatech.edu> CC: stable@vger.kernel.org # 4.19+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-05btrfs: prop: fix vanished compression property after failed setAnand Jain
commit 272e5326c7837697882ce3162029ba893059b616 upstream. The compression property resets to NULL, instead of the old value if we fail to set the new compression parameter. $ btrfs prop get /btrfs compression compression=lzo $ btrfs prop set /btrfs compression zli ERROR: failed to set compression for /btrfs: Invalid argument $ btrfs prop get /btrfs compression This is because the compression property ->validate() is successful for 'zli' as the strncmp() used the length passed from the userspace. Fix it by using the expected string length in strncmp(). Fixes: 63541927c8d1 ("Btrfs: add support for inode properties") Fixes: 5c1aab1dd544 ("btrfs: Add zstd support") CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-05btrfs: prop: fix zstd compression parameter validationAnand Jain
commit 50398fde997f6be8faebdb5f38e9c9c467370f51 upstream. We let pass zstd compression parameter even if it is not fully valid. For example: $ btrfs prop set /btrfs compression zst $ btrfs prop get /btrfs compression compression=zst zlib and lzo are fine. Fix it by checking the correct prefix length. Fixes: 5c1aab1dd544 ("btrfs: Add zstd support") CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-05Btrfs: do not allow trimming when a fs is mounted with the nologreplay optionFilipe Manana
commit f35f06c35560a86e841631f0243b83a984dc11a9 upstream. Whan a filesystem is mounted with the nologreplay mount option, which requires it to be mounted in RO mode as well, we can not allow discard on free space inside block groups, because log trees refer to extents that are not pinned in a block group's free space cache (pinning the extents is precisely the first phase of replaying a log tree). So do not allow the fitrim ioctl to do anything when the filesystem is mounted with the nologreplay option, because later it can be mounted RW without that option, which causes log replay to happen and result in either a failure to replay the log trees (leading to a mount failure), a crash or some silent corruption. Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Fixes: 96da09192cda ("btrfs: Introduce new mount option to disable tree log replay") CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-12btrfs: qgroup: Make qgroup async transaction commit more aggressiveQu Wenruo
commit f5fef4593653dfa2a865c485bb81415de51d5c99 upstream. [BUG] Btrfs qgroup will still hit EDQUOT under the following case: $ dev=/dev/test/test $ mnt=/mnt/btrfs $ umount $mnt &> /dev/null $ umount $dev &> /dev/null $ mkfs.btrfs -f $dev $ mount $dev $mnt -o nospace_cache $ btrfs subv create $mnt/subv $ btrfs quota enable $mnt $ btrfs quota rescan -w $mnt $ btrfs qgroup limit -e 1G $mnt/subv $ fallocate -l 900M $mnt/subv/padding $ sync $ rm $mnt/subv/padding # Hit EDQUOT $ xfs_io -f -c "pwrite 0 512M" $mnt/subv/real_file [CAUSE] Since commit a514d63882c3 ("btrfs: qgroup: Commit transaction in advance to reduce early EDQUOT"), btrfs is not forced to commit transaction to reclaim more quota space. Instead, we just check pertrans metadata reservation against some threshold and try to do asynchronously transaction commit. However in above case, the pertrans metadata reservation is pretty small thus it will never trigger asynchronous transaction commit. [FIX] Instead of only accounting pertrans metadata reservation, we calculate how much free space we have, and if there isn't much free space left, commit transaction asynchronously to try to free some space. This may slow down the fs when we have less than 32M free qgroup space, but should reduce a lot of false EDQUOT, so the cost should be acceptable. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-07Btrfs: fix assertion failure on fsync with NO_HOLES enabledFilipe Manana
commit 0ccc3876e4b2a1559a4dbe3126dda4459d38a83b upstream. Back in commit a89ca6f24ffe4 ("Btrfs: fix fsync after truncate when no_holes feature is enabled") I added an assertion that is triggered when an inline extent is found to assert that the length of the (uncompressed) data the extent represents is the same as the i_size of the inode, since that is true most of the time I couldn't find or didn't remembered about any exception at that time. Later on the assertion was expanded twice to deal with a case of a compressed inline extent representing a range that matches the sector size followed by an expanding truncate, and another case where fallocate can update the i_size of the inode without adding or updating existing extents (if the fallocate range falls entirely within the first block of the file). These two expansion/fixes of the assertion were done by commit 7ed586d0a8241 ("Btrfs: fix assertion on fsync of regular file when using no-holes feature") and commit 6399fb5a0b69a ("Btrfs: fix assertion failure during fsync in no-holes mode"). These however missed the case where an falloc expands the i_size of an inode to exactly the sector size and inline extent exists, for example: $ mkfs.btrfs -f -O no-holes /dev/sdc $ mount /dev/sdc /mnt $ xfs_io -f -c "pwrite -S 0xab 0 1096" /mnt/foobar wrote 1096/1096 bytes at offset 0 1 KiB, 1 ops; 0.0002 sec (4.448 MiB/sec and 4255.3191 ops/sec) $ xfs_io -c "falloc 1096 3000" /mnt/foobar $ xfs_io -c "fsync" /mnt/foobar Segmentation fault $ dmesg [701253.602385] assertion failed: len == i_size || (len == fs_info->sectorsize && btrfs_file_extent_compression(leaf, extent) != BTRFS_COMPRESS_NONE) || (len < i_size && i_size < fs_info->sectorsize), file: fs/btrfs/tree-log.c, line: 4727 [701253.602962] ------------[ cut here ]------------ [701253.603224] kernel BUG at fs/btrfs/ctree.h:3533! [701253.603503] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI [701253.603774] CPU: 2 PID: 7192 Comm: xfs_io Tainted: G W 5.0.0-rc8-btrfs-next-45 #1 [701253.604054] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014 [701253.604650] RIP: 0010:assfail.constprop.23+0x18/0x1a [btrfs] (...) [701253.605591] RSP: 0018:ffffbb48c186bc48 EFLAGS: 00010286 [701253.605914] RAX: 00000000000000de RBX: ffff921d0a7afc08 RCX: 0000000000000000 [701253.606244] RDX: 0000000000000000 RSI: ffff921d36b16868 RDI: ffff921d36b16868 [701253.606580] RBP: ffffbb48c186bcf0 R08: 0000000000000000 R09: 0000000000000000 [701253.606913] R10: 0000000000000003 R11: 0000000000000000 R12: ffff921d05d2de18 [701253.607247] R13: ffff921d03b54000 R14: 0000000000000448 R15: ffff921d059ecf80 [701253.607769] FS: 00007f14da906700(0000) GS:ffff921d36b00000(0000) knlGS:0000000000000000 [701253.608163] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [701253.608516] CR2: 000056087ea9f278 CR3: 00000002268e8001 CR4: 00000000003606e0 [701253.608880] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [701253.609250] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [701253.609608] Call Trace: [701253.609994] btrfs_log_inode+0xdfb/0xe40 [btrfs] [701253.610383] btrfs_log_inode_parent+0x2be/0xa60 [btrfs] [701253.610770] ? do_raw_spin_unlock+0x49/0xc0 [701253.611150] btrfs_log_dentry_safe+0x4a/0x70 [btrfs] [701253.611537] btrfs_sync_file+0x3b2/0x440 [btrfs] [701253.612010] ? do_sysinfo+0xb0/0xf0 [701253.612552] do_fsync+0x38/0x60 [701253.612988] __x64_sys_fsync+0x10/0x20 [701253.613360] do_syscall_64+0x60/0x1b0 [701253.613733] entry_SYSCALL_64_after_hwframe+0x49/0xbe [701253.614103] RIP: 0033:0x7f14da4e66d0 (...) [701253.615250] RSP: 002b:00007fffa670fdb8 EFLAGS: 00000246 ORIG_RAX: 000000000000004a [701253.615647] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f14da4e66d0 [701253.616047] RDX: 000056087ea9c260 RSI: 000056087ea9c260 RDI: 0000000000000003 [701253.616450] RBP: 0000000000000001 R08: 0000000000000020 R09: 0000000000000010 [701253.616854] R10: 000000000000009b R11: 0000000000000246 R12: 000056087ea9c260 [701253.617257] R13: 000056087ea9c240 R14: 0000000000000000 R15: 000056087ea9dd10 (...) [701253.619941] ---[ end trace e088d74f132b6da5 ]--- Updating the assertion again to allow for this particular case would result in a meaningless assertion, plus there is currently no risk of logging content that would result in any corruption after a log replay if the size of the data encoded in an inline extent is greater than the inode's i_size (which is not currently possibe either with or without compression), therefore just remove the assertion. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> [PG: removed assert block is slightly different in 4.18.x code base] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-07btrfs: Avoid possible qgroup_rsv_size overflow in ↵Nikolay Borisov
btrfs_calculate_inode_block_rsv_size commit 139a56170de67101791d6e6c8e940c6328393fe9 upstream. qgroup_rsv_size is calculated as the product of outstanding_extent * fs_info->nodesize. The product is calculated with 32 bit precision since both variables are defined as u32. Yet qgroup_rsv_size expects a 64 bit result. Avoid possible multiplication overflow by casting outstanding_extent to u64. Such overflow would in the worst case (64K nodesize) require more than 65536 extents, which is quite large and i'ts not likely that it would happen in practice. Fixes-coverity-id: 1435101 Fixes: ff6bc37eb7f6 ("btrfs: qgroup: Use independent and accurate per inode qgroup rsv") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-07btrfs: raid56: properly unmap parity page in finish_parity_scrub()Andrea Righi
commit 3897b6f0a859288c22fb793fad11ec2327e60fcd upstream. Parity page is incorrectly unmapped in finish_parity_scrub(), triggering a reference counter bug on i386, i.e.: [ 157.662401] kernel BUG at mm/highmem.c:349! [ 157.666725] invalid opcode: 0000 [#1] SMP PTI The reason is that kunmap(p_page) was completely left out, so we never did an unmap for the p_page and the loop unmapping the rbio page was iterating over the wrong number of stripes: unmapping should be done with nr_data instead of rbio->real_stripes. Test case to reproduce the bug: - create a raid5 btrfs filesystem: # mkfs.btrfs -m raid5 -d raid5 /dev/sdb /dev/sdc /dev/sdd /dev/sde - mount it: # mount /dev/sdb /mnt - run btrfs scrub in a loop: # while :; do btrfs scrub start -BR /mnt; done BugLink: https://bugs.launchpad.net/bugs/1812845 Fixes: 5a6ac9eacb49 ("Btrfs, raid56: support parity scrub on raid56") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-07btrfs: don't report readahead errors and don't update statisticsDavid Sterba
commit 0cc068e6ee59c1fffbfa977d8bf868b7551d80ac upstream. As readahead is an optimization, all errors are usually filtered out, but still properly handled when the real read call is done. The commit 5e9d398240b2 ("btrfs: readpages() should submit IO as read-ahead") added REQ_RAHEAD to readpages() because that's only used for readahead (despite what one would expect from the callback name). This causes a flood of messages and inflated read error stats, so skip reporting in case it's readahead. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202403 Reported-by: LimeTech <tomm@lime-technology.com> Fixes: 5e9d398240b2 ("btrfs: readpages() should submit IO as read-ahead") CC: stable@vger.kernel.org # 4.19+ Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-07btrfs: remove WARN_ON in log_dir_itemsJosef Bacik
commit 2cc8334270e281815c3850c3adea363c51f21e0d upstream. When Filipe added the recursive directory logging stuff in 2f2ff0ee5e430 ("Btrfs: fix metadata inconsistencies after directory fsync") he specifically didn't take the directory i_mutex for the children directories that we need to log because of lockdep. This is generally fine, but can lead to this WARN_ON() tripping if we happen to run delayed deletion's in between our first search and our second search of dir_item/dir_indexes for this directory. We expect this to happen, so the WARN_ON() isn't necessary. Drop the WARN_ON() and add a comment so we know why this case can happen. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-04-07Btrfs: fix incorrect file size after shrinking truncate and fsyncFilipe Manana
commit bf504110bc8aa05df48b0e5f0aa84bfb81e0574b upstream. If we do a shrinking truncate against an inode which is already present in the respective log tree and then rename it, as part of logging the new name we end up logging an inode item that reflects the old size of the file (the one which we previously logged) and not the new smaller size. The decision to preserve the size previously logged was added by commit 1a4bcf470c886b ("Btrfs: fix fsync data loss after adding hard link to inode") in order to avoid data loss after replaying the log. However that decision is only needed for the case the logged inode size is smaller then the current size of the inode, as explained in that commit's change log. If the current size of the inode is smaller then the previously logged size, we know a shrinking truncate happened and therefore need to use that smaller size. Example to trigger the problem: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -f -c "pwrite -S 0xab 0 8000" /mnt/foo $ xfs_io -c "fsync" /mnt/foo $ xfs_io -c "truncate 3000" /mnt/foo $ mv /mnt/foo /mnt/bar $ xfs_io -c "fsync" /mnt/bar <power failure> $ mount /dev/sdb /mnt $ od -t x1 -A d /mnt/bar 0000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab * 0008000 Once we rename the file, we log its name (and inode item), and because the inode was already logged before in the current transaction, we log it with a size of 8000 bytes because that is the size we previously logged (with the first fsync). As part of the rename, besides logging the inode, we do also sync the log, which is done since commit d4682ba03ef618 ("Btrfs: sync log after logging new name"), so the next fsync against our inode is effectively a no-op, since no new changes happened since the rename operation. Even if did not sync the log during the rename operation, the same problem (fize size of 8000 bytes instead of 3000 bytes) would be visible after replaying the log if the log ended up getting synced to disk through some other means, such as for example by fsyncing some other modified file. In the example above the fsync after the rename operation is there just because not every filesystem may guarantee logging/journalling the inode (and syncing the log/journal) during the rename operation, for example it is needed for f2fs, but not for ext4 and xfs. Fix this scenario by, when logging a new name (which is triggered by rename and link operations), using the current size of the inode instead of the previously logged inode size. A test case for fstests follows soon. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202695 CC: stable@vger.kernel.org # 4.4+ Reported-by: Seulbae Kim <seulbae@gatech.edu> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-26Btrfs: fix corruption reading shared and compressed extents after hole punchingFilipe Manana
commit 8e928218780e2f1cf2f5891c7575e8f0b284fcce upstream. In the past we had data corruption when reading compressed extents that are shared within the same file and they are consecutive, this got fixed by commit 005efedf2c7d0 ("Btrfs: fix read corruption of compressed and shared extents") and by commit 808f80b46790f ("Btrfs: update fix for read corruption of compressed and shared extents"). However there was a case that was missing in those fixes, which is when the shared and compressed extents are referenced with a non-zero offset. The following shell script creates a reproducer for this issue: #!/bin/bash mkfs.btrfs -f /dev/sdc &> /dev/null mount -o compress /dev/sdc /mnt/sdc # Create a file with 3 consecutive compressed extents, each has an # uncompressed size of 128Kb and a compressed size of 4Kb. for ((i = 1; i <= 3; i++)); do head -c 4096 /dev/zero for ((j = 1; j <= 31; j++)); do head -c 4096 /dev/zero | tr '\0' "\377" done done > /mnt/sdc/foobar sync echo "Digest after file creation: $(md5sum /mnt/sdc/foobar)" # Clone the first extent into offsets 128K and 256K. xfs_io -c "reflink /mnt/sdc/foobar 0 128K 128K" /mnt/sdc/foobar xfs_io -c "reflink /mnt/sdc/foobar 0 256K 128K" /mnt/sdc/foobar sync echo "Digest after cloning: $(md5sum /mnt/sdc/foobar)" # Punch holes into the regions that are already full of zeroes. xfs_io -c "fpunch 0 4K" /mnt/sdc/foobar xfs_io -c "fpunch 128K 4K" /mnt/sdc/foobar xfs_io -c "fpunch 256K 4K" /mnt/sdc/foobar sync echo "Digest after hole punching: $(md5sum /mnt/sdc/foobar)" echo "Dropping page cache..." sysctl -q vm.drop_caches=1 echo "Digest after hole punching: $(md5sum /mnt/sdc/foobar)" umount /dev/sdc When running the script we get the following output: Digest after file creation: 5a0888d80d7ab1fd31c229f83a3bbcc8 /mnt/sdc/foobar linked 131072/131072 bytes at offset 131072 128 KiB, 1 ops; 0.0033 sec (36.960 MiB/sec and 295.6830 ops/sec) linked 131072/131072 bytes at offset 262144 128 KiB, 1 ops; 0.0015 sec (78.567 MiB/sec and 628.5355 ops/sec) Digest after cloning: 5a0888d80d7ab1fd31c229f83a3bbcc8 /mnt/sdc/foobar Digest after hole punching: 5a0888d80d7ab1fd31c229f83a3bbcc8 /mnt/sdc/foobar Dropping page cache... Digest after hole punching: fba694ae8664ed0c2e9ff8937e7f1484 /mnt/sdc/foobar This happens because after reading all the pages of the extent in the range from 128K to 256K for example, we read the hole at offset 256K and then when reading the page at offset 260K we don't submit the existing bio, which is responsible for filling all the page in the range 128K to 256K only, therefore adding the pages from range 260K to 384K to the existing bio and submitting it after iterating over the entire range. Once the bio completes, the uncompressed data fills only the pages in the range 128K to 256K because there's no more data read from disk, leaving the pages in the range 260K to 384K unfilled. It is just a slightly different variant of what was solved by commit 005efedf2c7d0 ("Btrfs: fix read corruption of compressed and shared extents"). Fix this by forcing a bio submit, during readpages(), whenever we find a compressed extent map for a page that is different from the extent map for the previous page or has a different starting offset (in case it's the same compressed extent), instead of the extent map's original start offset. A test case for fstests follows soon. Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Fixes: 808f80b46790f ("Btrfs: update fix for read corruption of compressed and shared extents") Fixes: 005efedf2c7d0 ("Btrfs: fix read corruption of compressed and shared extents") Cc: stable@vger.kernel.org # 4.3+ Tested-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-26btrfs: ensure that a DUP or RAID1 block group has exactly two stripesJohannes Thumshirn
commit 349ae63f40638a28c6fce52e8447c2d14b84cc0c upstream. We recently had a customer issue with a corrupted filesystem. When trying to mount this image btrfs panicked with a division by zero in calc_stripe_length(). The corrupt chunk had a 'num_stripes' value of 1. calc_stripe_length() takes this value and divides it by the number of copies the RAID profile is expected to have to calculate the amount of data stripes. As a DUP profile is expected to have 2 copies this division resulted in 1/2 = 0. Later then the 'data_stripes' variable is used as a divisor in the stripe length calculation which results in a division by 0 and thus a kernel panic. When encountering a filesystem with a DUP block group and a 'num_stripes' value unequal to 2, refuse mounting as the image is corrupted and will lead to unexpected behaviour. Code inspection showed a RAID1 block group has the same issues. Fixes: e06cd3dd7cea ("Btrfs: add validadtion checks for chunk loading") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-26Btrfs: setup a nofs context for memory allocation at __btrfs_set_aclFilipe Manana
commit a0873490660246db587849a9e172f2b7b21fa88a upstream. We are holding a transaction handle when setting an acl, therefore we can not allocate the xattr value buffer using GFP_KERNEL, as we could deadlock if reclaim is triggered by the allocation, therefore setup a nofs context. Fixes: 39a27ec1004e8 ("btrfs: use GFP_KERNEL for xattr and acl allocations") CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-26Btrfs: setup a nofs context for memory allocation at btrfs_create_tree()Filipe Manana
commit b89f6d1fcb30a8cbdc18ce00c7d93792076af453 upstream. We are holding a transaction handle when creating a tree, therefore we can not allocate the root using GFP_KERNEL, as we could deadlock if reclaim is triggered by the allocation, therefore setup a nofs context. Fixes: 74e4d82757f74 ("btrfs: let callers of btrfs_alloc_root pass gfp flags") CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-01btrfs: use tagged writepage to mitigate livelock of snapshotEthan Lien
commit 3cd24c698004d2f7668e0eb9fc1f096f533c791b upstream. Snapshot is expected to be fast. But if there are writers steadily creating dirty pages in our subvolume, the snapshot may take a very long time to complete. To fix the problem, we use tagged writepage for snapshot flusher as we do in the generic write_cache_pages(), so we can omit pages dirtied after the snapshot command. This does not change the semantics regarding which data get to the snapshot, if there are pages being dirtied during the snapshotting operation. There's a sync called before snapshot is taken in old/new case, any IO in flight just after that may be in the snapshot but this depends on other system effects that might still sync the IO. We do a simple snapshot speed test on a Intel D-1531 box: fio --ioengine=libaio --iodepth=32 --bs=4k --rw=write --size=64G --direct=0 --thread=1 --numjobs=1 --time_based --runtime=120 --filename=/mnt/sub/testfile --name=job1 --group_reporting & sleep 5; time btrfs sub snap -r /mnt/sub /mnt/snap; killall fio original: 1m58sec patched: 6.54sec This is the best case for this patch since for a sequential write case, we omit nearly all pages dirtied after the snapshot command. For a multi writers, random write test: fio --ioengine=libaio --iodepth=32 --bs=4k --rw=randwrite --size=64G --direct=0 --thread=1 --numjobs=4 --time_based --runtime=120 --filename=/mnt/sub/testfile --name=job1 --group_reporting & sleep 5; time btrfs sub snap -r /mnt/sub /mnt/snap; killall fio original: 15.83sec patched: 10.35sec The improvement is smaller compared to the sequential write case, since we omit only half of the pages dirtied after snapshot command. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Ethan Lien <ethanlien@synology.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-03-01btrfs: harden agaist duplicate fsid on scanned devicesAnand Jain
commit a9261d4125c97ce8624e9941b75dee1b43ad5df9 upstream. It's not that impossible to imagine that a device OR a btrfs image is copied just by using the dd or the cp command. Which in case both the copies of the btrfs will have the same fsid. If on the system with automount enabled, the copied FS gets scanned. We have a known bug in btrfs, that we let the device path be changed after the device has been mounted. So using this loop hole the new copied device would appears as if its mounted immediately after it's been copied. For example: Initially.. /dev/mmcblk0p4 is mounted as / $ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT mmcblk0 179:0 0 29.2G 0 disk |-mmcblk0p4 179:4 0 4G 0 part / |-mmcblk0p2 179:2 0 500M 0 part /boot |-mmcblk0p3 179:3 0 256M 0 part [SWAP] `-mmcblk0p1 179:1 0 256M 0 part /boot/efi $ btrfs fi show Label: none uuid: 07892354-ddaa-4443-90ea-f76a06accaba Total devices 1 FS bytes used 1.40GiB devid 1 size 4.00GiB used 3.00GiB path /dev/mmcblk0p4 Copy mmcblk0 to sda $ dd if=/dev/mmcblk0 of=/dev/sda And immediately after the copy completes the change in the device superblock is notified which the automount scans using btrfs device scan and the new device sda becomes the mounted root device. $ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 1 14.9G 0 disk |-sda4 8:4 1 4G 0 part / |-sda2 8:2 1 500M 0 part |-sda3 8:3 1 256M 0 part `-sda1 8:1 1 256M 0 part mmcblk0 179:0 0 29.2G 0 disk |-mmcblk0p4 179:4 0 4G 0 part |-mmcblk0p2 179:2 0 500M 0 part /boot |-mmcblk0p3 179:3 0 256M 0 part [SWAP] `-mmcblk0p1 179:1 0 256M 0 part /boot/efi $ btrfs fi show / Label: none uuid: 07892354-ddaa-4443-90ea-f76a06accaba Total devices 1 FS bytes used 1.40GiB devid 1 size 4.00GiB used 3.00GiB path /dev/sda4 The bug is quite nasty that you can't either unmount /dev/sda4 or /dev/mmcblk0p4. And the problem does not get solved until you take sda out of the system on to another system to change its fsid using the 'btrfstune -u' command. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-19btrfs: On error always free subvol_name in btrfs_mountEric W. Biederman
commit 532b618bdf237250d6d4566536d4b6ce3d0a31fe upstream. The subvol_name is allocated in btrfs_parse_subvol_options and is consumed and freed in mount_subvol. Add a free to the error paths that don't call mount_subvol so that it is guaranteed that subvol_name is freed when an error happens. Fixes: 312c89fbca06 ("btrfs: cleanup btrfs_mount() using btrfs_mount_root()") Cc: stable@vger.kernel.org # v4.19+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-19Btrfs: fix deadlock when allocating tree block during leaf/node splitFilipe Manana
commit a6279470762c19ba97e454f90798373dccdf6148 upstream. When splitting a leaf or node from one of the trees that are modified when flushing pending block groups (extent, chunk, device and free space trees), we need to allocate a new tree block, which in turn can result in the need to allocate a new block group. After allocating the new block group we may need to flush new block groups that were previously allocated during the course of the current transaction, which is what may cause a deadlock due to attempts to write lock twice the same leaf or node, as when splitting a leaf or node we are holding a write lock on it and its parent node. The same type of deadlock can also happen when increasing the tree's height, since we are holding a lock on the existing root while allocating the tree block to use as the new root node. An example trace when the deadlock happens during the leaf split path is: [27175.293054] CPU: 0 PID: 3005 Comm: kworker/u17:6 Tainted: G W 4.19.16 #1 [27175.293942] Hardware name: Penguin Computing Relion 1900/MD90-FS0-ZB-XX, BIOS R15 06/25/2018 [27175.294846] Workqueue: btrfs-extent-refs btrfs_extent_refs_helper [btrfs] (...) [27175.298384] RSP: 0018:ffffab2087107758 EFLAGS: 00010246 [27175.299269] RAX: 0000000000000bbd RBX: ffff9fadc7141c48 RCX: 0000000000000001 [27175.300155] RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff9fadc7141c48 [27175.301023] RBP: 0000000000000001 R08: ffff9faeb6ac1040 R09: ffff9fa9c0000000 [27175.301887] R10: 0000000000000000 R11: 0000000000000040 R12: ffff9fb21aac8000 [27175.302743] R13: ffff9fb1a64d6a20 R14: 0000000000000001 R15: ffff9fb1a64d6a18 [27175.303601] FS: 0000000000000000(0000) GS:ffff9fb21fa00000(0000) knlGS:0000000000000000 [27175.304468] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [27175.305339] CR2: 00007fdc8743ead8 CR3: 0000000763e0a006 CR4: 00000000003606f0 [27175.306220] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [27175.307087] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [27175.307940] Call Trace: [27175.308802] btrfs_search_slot+0x779/0x9a0 [btrfs] [27175.309669] ? update_space_info+0xba/0xe0 [btrfs] [27175.310534] btrfs_insert_empty_items+0x67/0xc0 [btrfs] [27175.311397] btrfs_insert_item+0x60/0xd0 [btrfs] [27175.312253] btrfs_create_pending_block_groups+0xee/0x210 [btrfs] [27175.313116] do_chunk_alloc+0x25f/0x300 [btrfs] [27175.313984] find_free_extent+0x706/0x10d0 [btrfs] [27175.314855] btrfs_reserve_extent+0x9b/0x1d0 [btrfs] [27175.315707] btrfs_alloc_tree_block+0x100/0x5b0 [btrfs] [27175.316548] split_leaf+0x130/0x610 [btrfs] [27175.317390] btrfs_search_slot+0x94d/0x9a0 [btrfs] [27175.318235] btrfs_insert_empty_items+0x67/0xc0 [btrfs] [27175.319087] alloc_reserved_file_extent+0x84/0x2c0 [btrfs] [27175.319938] __btrfs_run_delayed_refs+0x596/0x1150 [btrfs] [27175.320792] btrfs_run_delayed_refs+0xed/0x1b0 [btrfs] [27175.321643] delayed_ref_async_start+0x81/0x90 [btrfs] [27175.322491] normal_work_helper+0xd0/0x320 [btrfs] [27175.323328] ? move_linked_works+0x6e/0xa0 [27175.324160] process_one_work+0x191/0x370 [27175.324976] worker_thread+0x4f/0x3b0 [27175.325763] kthread+0xf8/0x130 [27175.326531] ? rescuer_thread+0x320/0x320 [27175.327284] ? kthread_create_worker_on_cpu+0x50/0x50 [27175.328027] ret_from_fork+0x35/0x40 [27175.328741] ---[ end trace 300a1b9f0ac30e26 ]--- Fix this by preventing the flushing of new blocks groups when splitting a leaf/node and when inserting a new root node for one of the trees modified by the flushing operation, similar to what is done when COWing a node/leaf from on of these trees. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202383 Reported-by: Eli V <eliventer@gmail.com> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-05btrfs: improve error handling of btrfs_add_linkJohannes Thumshirn
commit 1690dd41e0cb1dade80850ed8a3eb0121b96d22f upstream. In the error handling block, err holds the return value of either btrfs_del_root_ref() or btrfs_del_inode_ref() but it hasn't been checked since it's introduction with commit fe66a05a0679 (Btrfs: improve error handling for btrfs_insert_dir_item callers) in 2012. If the error handling in the error handling fails, there's not much left to do and the abort either happened earlier in the callees or is necessary here. So if one of btrfs_del_root_ref() or btrfs_del_inode_ref() failed, abort the transaction, but still return the original code of the failure stored in 'ret' as this will be reported to the user. Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-05btrfs: alloc_chunk: fix more DUP stripe size handlingHans van Kranenburg
commit baf92114c7e6dd6124aa3d506e4bc4b694da3bc3 upstream. Commit 92e222df7b "btrfs: alloc_chunk: fix DUP stripe size handling" fixed calculating the stripe_size for a new DUP chunk. However, the same calculation reappears a bit later, and that one was not changed yet. The resulting bug that is exposed is that the newly allocated device extents ('stripes') can have a few MiB overlap with the next thing stored after them, which is another device extent or the end of the disk. The scenario in which this can happen is: * The block device for the filesystem is less than 10GiB in size. * The amount of contiguous free unallocated disk space chosen to use for chunk allocation is 20% of the total device size, or a few MiB more or less. An example: - The filesystem device is 7880MiB (max_chunk_size gets set to 788MiB) - There's 1578MiB unallocated raw disk space left in one contiguous piece. In this case stripe_size is first calculated as 789MiB, (half of 1578MiB). Since 789MiB (stripe_size * data_stripes) > 788MiB (max_chunk_size), we enter the if block. Now stripe_size value is immediately overwritten while calculating an adjusted value based on max_chunk_size, which ends up as 788MiB. Next, the value is rounded up to a 16MiB boundary, 800MiB, which is actually more than the value we had before. However, the last comparison fails to detect this, because it's comparing the value with the total amount of free space, which is about twice the size of stripe_size. In the example above, this means that the resulting raw disk space being allocated is 1600MiB, while only a gap of 1578MiB has been found. The second device extent object for this DUP chunk will overlap for 22MiB with whatever comes next. The underlying problem here is that the stripe_size is reused all the time for different things. So, when entering the code in the if block, stripe_size is immediately overwritten with something else. If later we decide we want to have the previous value back, then the logic to compute it was copy pasted in again. With this change, the value in stripe_size is not unnecessarily destroyed, so the duplicated calculation is not needed any more. Signed-off-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-05btrfs: wait on ordered extents on abort cleanupJosef Bacik
commit 74d5d229b1bf60f93bff244b2dfc0eb21ec32a07 upstream. If we flip read-only before we initiate writeback on all dirty pages for ordered extents we've created then we'll have ordered extents left over on umount, which results in all sorts of bad things happening. Fix this by making sure we wait on ordered extents if we have to do the aborted transaction cleanup stuff. generic/475 can produce this warning: [ 8531.177332] WARNING: CPU: 2 PID: 11997 at fs/btrfs/disk-io.c:3856 btrfs_free_fs_root+0x95/0xa0 [btrfs] [ 8531.183282] CPU: 2 PID: 11997 Comm: umount Tainted: G W 5.0.0-rc1-default+ #394 [ 8531.185164] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014 [ 8531.187851] RIP: 0010:btrfs_free_fs_root+0x95/0xa0 [btrfs] [ 8531.193082] RSP: 0018:ffffb1ab86163d98 EFLAGS: 00010286 [ 8531.194198] RAX: ffff9f3449494d18 RBX: ffff9f34a2695000 RCX:0000000000000000 [ 8531.195629] RDX: 0000000000000002 RSI: 0000000000000001 RDI:0000000000000000 [ 8531.197315] RBP: ffff9f344e930000 R08: 0000000000000001 R09:0000000000000000 [ 8531.199095] R10: 0000000000000000 R11: ffff9f34494d4ff8 R12:ffffb1ab86163dc0 [ 8531.200870] R13: ffff9f344e9300b0 R14: ffffb1ab86163db8 R15:0000000000000000 [ 8531.202707] FS: 00007fc68e949fc0(0000) GS:ffff9f34bd800000(0000)knlGS:0000000000000000 [ 8531.204851] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8531.205942] CR2: 00007ffde8114dd8 CR3: 000000002dfbd000 CR4:00000000000006e0 [ 8531.207516] Call Trace: [ 8531.208175] btrfs_free_fs_roots+0xdb/0x170 [btrfs] [ 8531.210209] ? wait_for_completion+0x5b/0x190 [ 8531.211303] close_ctree+0x157/0x350 [btrfs] [ 8531.212412] generic_shutdown_super+0x64/0x100 [ 8531.213485] kill_anon_super+0x14/0x30 [ 8531.214430] btrfs_kill_super+0x12/0xa0 [btrfs] [ 8531.215539] deactivate_locked_super+0x29/0x60 [ 8531.216633] cleanup_mnt+0x3b/0x70 [ 8531.217497] task_work_run+0x98/0xc0 [ 8531.218397] exit_to_usermode_loop+0x83/0x90 [ 8531.219324] do_syscall_64+0x15b/0x180 [ 8531.220192] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 8531.221286] RIP: 0033:0x7fc68e5e4d07 [ 8531.225621] RSP: 002b:00007ffde8116608 EFLAGS: 00000246 ORIG_RAX:00000000000000a6 [ 8531.227512] RAX: 0000000000000000 RBX: 00005580c2175970 RCX:00007fc68e5e4d07 [ 8531.229098] RDX: 0000000000000001 RSI: 0000000000000000 RDI:00005580c2175b80 [ 8531.230730] RBP: 0000000000000000 R08: 00005580c2175ba0 R09:00007ffde8114e80 [ 8531.232269] R10: 0000000000000000 R11: 0000000000000246 R12:00005580c2175b80 [ 8531.233839] R13: 00007fc68eac61c4 R14: 00005580c2175a68 R15:0000000000000000 Leaving a tree in the rb-tree: 3853 void btrfs_free_fs_root(struct btrfs_root *root) 3854 { 3855 iput(root->ino_cache_inode); 3856 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree)); CC: stable@vger.kernel.org Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> [ add stacktrace ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-05Revert "btrfs: balance dirty metadata pages in btrfs_finish_ordered_io"David Sterba
commit 77b7aad195099e7c6da11e94b7fa6ef5e6fb0025 upstream. This reverts commit e73e81b6d0114d4a303205a952ab2e87c44bd279. This patch causes a few problems: - adds latency to btrfs_finish_ordered_io - as btrfs_finish_ordered_io is used for free space cache, generating more work from btrfs_btree_balance_dirty_nodelay could end up in the same workque, effectively deadlocking 12260 kworker/u96:16+btrfs-freespace-write D [<0>] balance_dirty_pages+0x6e6/0x7ad [<0>] balance_dirty_pages_ratelimited+0x6bb/0xa90 [<0>] btrfs_finish_ordered_io+0x3da/0x770 [<0>] normal_work_helper+0x1c5/0x5a0 [<0>] process_one_work+0x1ee/0x5a0 [<0>] worker_thread+0x46/0x3d0 [<0>] kthread+0xf5/0x130 [<0>] ret_from_fork+0x24/0x30 [<0>] 0xffffffffffffffff Transaction commit will wait on the freespace cache: 838 btrfs-transacti D [<0>] btrfs_start_ordered_extent+0x154/0x1e0 [<0>] btrfs_wait_ordered_range+0xbd/0x110 [<0>] __btrfs_wait_cache_io+0x49/0x1a0 [<0>] btrfs_write_dirty_block_groups+0x10b/0x3b0 [<0>] commit_cowonly_roots+0x215/0x2b0 [<0>] btrfs_commit_transaction+0x37e/0x910 [<0>] transaction_kthread+0x14d/0x180 [<0>] kthread+0xf5/0x130 [<0>] ret_from_fork+0x24/0x30 [<0>] 0xffffffffffffffff And then writepages ends up waiting on transaction commit: 9520 kworker/u96:13+flush-btrfs-1 D [<0>] wait_current_trans+0xac/0xe0 [<0>] start_transaction+0x21b/0x4b0 [<0>] cow_file_range_inline+0x10b/0x6b0 [<0>] cow_file_range.isra.69+0x329/0x4a0 [<0>] run_delalloc_range+0x105/0x3c0 [<0>] writepage_delalloc+0x119/0x180 [<0>] __extent_writepage+0x10c/0x390 [<0>] extent_write_cache_pages+0x26f/0x3d0 [<0>] extent_writepages+0x4f/0x80 [<0>] do_writepages+0x17/0x60 [<0>] __writeback_single_inode+0x59/0x690 [<0>] writeback_sb_inodes+0x291/0x4e0 [<0>] __writeback_inodes_wb+0x87/0xb0 [<0>] wb_writeback+0x3bb/0x500 [<0>] wb_workfn+0x40d/0x610 [<0>] process_one_work+0x1ee/0x5a0 [<0>] worker_thread+0x1e0/0x3d0 [<0>] kthread+0xf5/0x130 [<0>] ret_from_fork+0x24/0x30 [<0>] 0xffffffffffffffff Eventually, we have every process in the system waiting on balance_dirty_pages(), and nobody is able to make progress on page writeback. The original patch tried to fix an OOM condition, that happened on 4.4 but no success reproducing that on later kernels (4.19 and 4.20). This is more likely a problem in OOM itself. Link: https://lore.kernel.org/linux-btrfs/20180528054821.9092-1-ethanlien@synology.com/ Reported-by: Chris Mason <clm@fb.com> CC: stable@vger.kernel.org # 4.18+ CC: ethanlien <ethanlien@synology.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-05Btrfs: use nofs context when initializing security xattrs to avoid deadlockFilipe Manana
commit 827aa18e7b903c5ff3b3cd8fec328a99b1dbd411 upstream. When initializing the security xattrs, we are holding a transaction handle therefore we need to use a GFP_NOFS context in order to avoid a deadlock with reclaim in case it's triggered. Fixes: 39a27ec1004e8 ("btrfs: use GFP_KERNEL for xattr and acl allocations") Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-02-05Btrfs: fix access to available allocation bits when starting balanceFilipe Manana
commit 5a8067c0d17feb7579db0476191417b441a8996e upstream. The available allocation bits members from struct btrfs_fs_info are protected by a sequence lock, and when starting balance we access them incorrectly in two different ways: 1) In the read sequence lock loop at btrfs_balance() we use the values we read from fs_info->avail_*_alloc_bits and we can immediately do actions that have side effects and can not be undone (printing a message and jumping to a label). This is wrong because a retry might be needed, so our actions must not have side effects and must be repeatable as long as read_seqretry() returns a non-zero value. In other words, we were essentially ignoring the sequence lock; 2) Right below the read sequence lock loop, we were reading the values from avail_metadata_alloc_bits and avail_data_alloc_bits without any protection from concurrent writers, that is, reading them outside of the read sequence lock critical section. So fix this by making sure we only read the available allocation bits while in a read sequence lock critical section and that what we do in the critical section is repeatable (has nothing that can not be undone) so that any eventual retry that is needed is handled properly. Fixes: de98ced9e743 ("Btrfs: use seqlock to protect fs_info->avail_{data, metadata, system}_alloc_bits") Fixes: 14506127979a ("btrfs: fix a bogus warning when converting only data or metadata") Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-01-12Btrfs: send, fix race with transaction commits that create snapshotsFilipe Manana
commit be6821f82c3cc36e026f5afd10249988852b35ea upstream. If we create a snapshot of a snapshot currently being used by a send operation, we can end up with send failing unexpectedly (returning -ENOENT error to user space for example). The following diagram shows how this happens. CPU 1 CPU2 CPU3 btrfs_ioctl_send() (...) create_snapshot() -> creates snapshot of a root used by the send task btrfs_commit_transaction() create_pending_snapshot() __get_inode_info() btrfs_search_slot() btrfs_search_slot_get_root() down_read commit_root_sem get reference on eb of the commit root -> eb with bytenr == X up_read commit_root_sem btrfs_cow_block(root node) btrfs_free_tree_block() -> creates delayed ref to free the extent btrfs_run_delayed_refs() -> runs the delayed ref, adds extent to fs_info->pinned_extents btrfs_finish_extent_commit() unpin_extent_range() -> marks extent as free in the free space cache transaction commit finishes btrfs_start_transaction() (...) btrfs_cow_block() btrfs_alloc_tree_block() btrfs_reserve_extent() -> allocates extent at bytenr == X btrfs_init_new_buffer(bytenr X) btrfs_find_create_tree_block() alloc_extent_buffer(bytenr X) find_extent_buffer(bytenr X) -> returns existing eb, which the send task got (...) -> modifies content of the eb with bytenr == X -> uses an eb that now belongs to some other tree and no more matches the commit root of the snapshot, resuts will be unpredictable The consequences of this race can be various, and can lead to searches in the commit root performed by the send task failing unexpectedly (unable to find inode items, returning -ENOENT to user space, for example) or not failing because an inode item with the same number was added to the tree that reused the metadata extent, in which case send can behave incorrectly in the worst case or just fail later for some reason. Fix this by performing a copy of the commit root's extent buffer when doing a search in the context of a send operation. CC: stable@vger.kernel.org # 4.4.x: 1fc28d8e2e9: Btrfs: move get root out of btrfs_search_slot to a helper CC: stable@vger.kernel.org # 4.4.x: f9ddfd0592a: Btrfs: remove unused check of skip_locking CC: stable@vger.kernel.org # 4.4.x Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-01-12btrfs: run delayed items before dropping the snapshotJosef Bacik
commit 0568e82dbe2510fc1fa664f58e5c997d3f1e649e upstream. With my delayed refs patches in place we started seeing a large amount of aborts in __btrfs_free_extent: BTRFS error (device sdb1): unable to find ref byte nr 91947008 parent 0 root 35964 owner 1 offset 0 Call Trace: ? btrfs_merge_delayed_refs+0xaf/0x340 __btrfs_run_delayed_refs+0x6ea/0xfc0 ? btrfs_set_path_blocking+0x31/0x60 btrfs_run_delayed_refs+0xeb/0x180 btrfs_commit_transaction+0x179/0x7f0 ? btrfs_check_space_for_delayed_refs+0x30/0x50 ? should_end_transaction.isra.19+0xe/0x40 btrfs_drop_snapshot+0x41c/0x7c0 btrfs_clean_one_deleted_snapshot+0xb5/0xd0 cleaner_kthread+0xf6/0x120 kthread+0xf8/0x130 ? btree_invalidatepage+0x90/0x90 ? kthread_bind+0x10/0x10 ret_from_fork+0x35/0x40 This was because btrfs_drop_snapshot depends on the root not being modified while it's dropping the snapshot. It will unlock the root node (and really every node) as it walks down the tree, only to re-lock it when it needs to do something. This is a problem because if we modify the tree we could cow a block in our path, which frees our reference to that block. Then once we get back to that shared block we'll free our reference to it again, and get ENOENT when trying to lookup our extent reference to that block in __btrfs_free_extent. This is ultimately happening because we have delayed items left to be processed for our deleted snapshot _after_ all of the inodes are closed for the snapshot. We only run the delayed inode item if we're deleting the inode, and even then we do not run the delayed insertions or delayed removals. These can be run at any point after our final inode does its last iput, which is what triggers the snapshot deletion. We can end up with the snapshot deletion happening and then have the delayed items run on that file system, resulting in the above problem. This problem has existed forever, however my patches made it much easier to hit as I wake up the cleaner much more often to deal with delayed iputs, which made us more likely to start the snapshot dropping work before the transaction commits, which is when the delayed items would generally be run. Before, generally speaking, we would run the delayed items, commit the transaction, and wakeup the cleaner thread to start deleting snapshots, which means we were less likely to hit this problem. You could still hit it if you had multiple snapshots to be deleted and ended up with lots of delayed items, but it was definitely harder. Fix for now by simply running all the delayed items before starting to drop the snapshot. We could make this smarter in the future by making the delayed items per-root, and then simply drop any delayed items for roots that we are going to delete. But for now just a quick and easy solution is the safest. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-01-12Btrfs: fix fsync of files with multiple hard links in new directoriesFilipe Manana
commit 41bd60676923822de1df2c50b3f9a10171f4338a upstream. The log tree has a long standing problem that when a file is fsync'ed we only check for new ancestors, created in the current transaction, by following only the hard link for which the fsync was issued. We follow the ancestors using the VFS' dget_parent() API. This means that if we create a new link for a file in a directory that is new (or in an any other new ancestor directory) and then fsync the file using an old hard link, we end up not logging the new ancestor, and on log replay that new hard link and ancestor do not exist. In some cases, involving renames, the file will not exist at all. Example: mkfs.btrfs -f /dev/sdb mount /dev/sdb /mnt mkdir /mnt/A touch /mnt/foo ln /mnt/foo /mnt/A/bar xfs_io -c fsync /mnt/foo <power failure> In this example after log replay only the hard link named 'foo' exists and directory A does not exist, which is unexpected. In other major linux filesystems, such as ext4, xfs and f2fs for example, both hard links exist and so does directory A after mounting again the filesystem. Checking if any new ancestors are new and need to be logged was added in 2009 by commit 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes"), however only for the ancestors of the hard link (dentry) for which the fsync was issued, instead of checking for all ancestors for all of the inode's hard links. So fix this by tracking the id of the last transaction where a hard link was created for an inode and then on fsync fallback to a full transaction commit when an inode has more than one hard link and at least one new hard link was created in the current transaction. This is the simplest solution since this is not a common use case (adding frequently hard links for which there's an ancestor created in the current transaction and then fsync the file). In case it ever becomes a common use case, a solution that consists of iterating the fs/subvol btree for each hard link and check if any ancestor is new, could be implemented. This solves many unexpected scenarios reported by Jayashree Mohan and Vijay Chidambaram, and for which there is a new test case for fstests under review. Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes") CC: stable@vger.kernel.org # 4.4+ Reported-by: Vijay Chidambaram <vvijay03@gmail.com> Reported-by: Jayashree Mohan <jayashree2912@gmail.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-01-12btrfs: skip file_extent generation check for free_space_inode in ↵Lu Fengqi
run_delalloc_nocow commit 27a7ff554e8d349627a90bda275c527b7348adae upstream. The test case btrfs/001 with inode_cache mount option will encounter the following warning: WARNING: CPU: 1 PID: 23700 at fs/btrfs/inode.c:956 cow_file_range.isra.19+0x32b/0x430 [btrfs] CPU: 1 PID: 23700 Comm: btrfs Kdump: loaded Tainted: G W O 4.20.0-rc4-custom+ #30 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:cow_file_range.isra.19+0x32b/0x430 [btrfs] Call Trace: ? free_extent_buffer+0x46/0x90 [btrfs] run_delalloc_nocow+0x455/0x900 [btrfs] btrfs_run_delalloc_range+0x1a7/0x360 [btrfs] writepage_delalloc+0xf9/0x150 [btrfs] __extent_writepage+0x125/0x3e0 [btrfs] extent_write_cache_pages+0x1b6/0x3e0 [btrfs] ? __wake_up_common_lock+0x63/0xc0 extent_writepages+0x50/0x80 [btrfs] do_writepages+0x41/0xd0 ? __filemap_fdatawrite_range+0x9e/0xf0 __filemap_fdatawrite_range+0xbe/0xf0 btrfs_fdatawrite_range+0x1b/0x50 [btrfs] __btrfs_write_out_cache+0x42c/0x480 [btrfs] btrfs_write_out_ino_cache+0x84/0xd0 [btrfs] btrfs_save_ino_cache+0x551/0x660 [btrfs] commit_fs_roots+0xc5/0x190 [btrfs] btrfs_commit_transaction+0x2bf/0x8d0 [btrfs] btrfs_mksubvol+0x48d/0x4d0 [btrfs] btrfs_ioctl_snap_create_transid+0x170/0x180 [btrfs] btrfs_ioctl_snap_create_v2+0x124/0x180 [btrfs] btrfs_ioctl+0x123f/0x3030 [btrfs] The file extent generation of the free space inode is equal to the last snapshot of the file root, so the inode will be passed to cow_file_rage. But the inode was created and its extents were preallocated in btrfs_save_ino_cache, there are no cow copies on disk. The preallocated extent is not yet in the extent tree, and btrfs_cross_ref_exist will ignore the -ENOENT returned by check_committed_ref, so we can directly write the inode to the disk. Fixes: 78d4295b1eee ("btrfs: lift some btrfs_cross_ref_exist checks in nocow path") CC: stable@vger.kernel.org # 4.18+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-01-12btrfs: dev-replace: go back to suspend state if another EXCL_OP is runningAnand Jain
commit 05c49e6bc1e8866ecfd674ebeeb58cdbff9145c2 upstream. In a secnario where balance and replace co-exists as below, - start balance - pause balance - start replace - reboot and when system restarts, balance resumes first. Then the replace is attempted to restart but will fail as the EXCL_OP lock is already held by the balance. If so place the replace state back to BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED state. Fixes: 010a47bde9420 ("btrfs: add proper safety check before resuming dev-replace") CC: stable@vger.kernel.org # 4.18+ Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-01-12btrfs: dev-replace: go back to suspended state if target device is missingAnand Jain
commit 0d228ece59a35a9b9e8ff0d40653234a6d90f61e upstream. At the time of forced unmount we place the running replace to BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED state, so when the system comes back and expect the target device is missing. Then let the replace state continue to be in BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED state instead of BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED as there isn't any matching scrub running as part of replace. Fixes: e93c89c1aaaa ("Btrfs: add new sources for device replace code") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2018-12-30Btrfs: send, fix infinite loop due to directory rename dependenciesRobbie Ko
commit a4390aee72713d9e73f1132bcdeb17d72fbbf974 upstream. When doing an incremental send, due to the need of delaying directory move (rename) operations we can end up in infinite loop at apply_children_dir_moves(). An example scenario that triggers this problem is described below, where directory names correspond to the numbers of their respective inodes. Parent snapshot: . |--- 261/ |--- 271/ |--- 266/ |--- 259/ |--- 260/ | |--- 267 | |--- 264/ | |--- 258/ | |--- 257/ | |--- 265/ |--- 268/ |--- 269/ | |--- 262/ | |--- 270/ |--- 272/ | |--- 263/ | |--- 275/ | |--- 274/ |--- 273/ Send snapshot: . |-- 275/ |-- 274/ |-- 273/ |-- 262/ |-- 269/ |-- 258/ |-- 271/ |-- 268/ |-- 267/ |-- 270/ |-- 259/ | |-- 265/ | |-- 272/ |-- 257/ |-- 260/ |-- 264/ |-- 263/ |-- 261/ |-- 266/ When processing inode 257 we delay its move (rename) operation because its new parent in the send snapshot, inode 272, was not yet processed. Then when processing inode 272, we delay the move operation for that inode because inode 274 is its ancestor in the send snapshot. Finally we delay the move operation for inode 274 when processing it because inode 275 is its new parent in the send snapshot and was not yet moved. When finishing processing inode 275, we start to do the move operations that were previously delayed (at apply_children_dir_moves()), resulting in the following iterations: 1) We issue the move operation for inode 274; 2) Because inode 262 depended on the move operation of inode 274 (it was delayed because 274 is its ancestor in the send snapshot), we issue the move operation for inode 262; 3) We issue the move operation for inode 272, because it was delayed by inode 274 too (ancestor of 272 in the send snapshot); 4) We issue the move operation for inode 269 (it was delayed by 262); 5) We issue the move operation for inode 257 (it was delayed by 272); 6) We issue the move operation for inode 260 (it was delayed by 272); 7) We issue the move operation for inode 258 (it was delayed by 269); 8) We issue the move operation for inode 264 (it was delayed by 257); 9) We issue the move operation for inode 271 (it was delayed by 258); 10) We issue the move operation for inode 263 (it was delayed by 264); 11) We issue the move operation for inode 268 (it was delayed by 271); 12) We verify if we can issue the move operation for inode 270 (it was delayed by 271). We detect a path loop in the current state, because inode 267 needs to be moved first before we can issue the move operation for inode 270. So we delay again the move operation for inode 270, this time we will attempt to do it after inode 267 is moved; 13) We issue the move operation for inode 261 (it was delayed by 263); 14) We verify if we can issue the move operation for inode 266 (it was delayed by 263). We detect a path loop in the current state, because inode 270 needs to be moved first before we can issue the move operation for inode 266. So we delay again the move operation for inode 266, this time we will attempt to do it after inode 270 is moved (its move operation was delayed in step 12); 15) We issue the move operation for inode 267 (it was delayed by 268); 16) We verify if we can issue the move operation for inode 266 (it was delayed by 270). We detect a path loop in the current state, because inode 270 needs to be moved first before we can issue the move operation for inode 266. So we delay again the move operation for inode 266, this time we will attempt to do it after inode 270 is moved (its move operation was delayed in step 12). So here we added again the same delayed move operation that we added in step 14; 17) We attempt again to see if we can issue the move operation for inode 266, and as in step 16, we realize we can not due to a path loop in the current state due to a dependency on inode 270. Again we delay inode's 266 rename to happen after inode's 270 move operation, adding the same dependency to the empty stack that we did in steps 14 and 16. The next iteration will pick the same move dependency on the stack (the only entry) and realize again there is still a path loop and then again the same dependency to the stack, over and over, resulting in an infinite loop. So fix this by preventing adding the same move dependency entries to the stack by removing each pending move record from the red black tree of pending moves. This way the next call to get_pending_dir_moves() will not return anything for the current parent inode. A test case for fstests, with this reproducer, follows soon. Signed-off-by: Robbie Ko <robbieko@synology.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> [Wrote changelog with example and more clear explanation] Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>