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2021-04-20btrfs: zoned: automatically reclaim zonesJohannes Thumshirn
When a file gets deleted on a zoned file system, the space freed is not returned back into the block group's free space, but is migrated to zone_unusable. As this zone_unusable space is behind the current write pointer it is not possible to use it for new allocations. In the current implementation a zone is reset once all of the block group's space is accounted as zone unusable. This behaviour can lead to premature ENOSPC errors on a busy file system. Instead of only reclaiming the zone once it is completely unusable, kick off a reclaim job once the amount of unusable bytes exceeds a user configurable threshold between 51% and 100%. It can be set per mounted filesystem via the sysfs tunable bg_reclaim_threshold which is set to 75% by default. Similar to reclaiming unused block groups, these dirty block groups are added to a to_reclaim list and then on a transaction commit, the reclaim process is triggered but after we deleted unused block groups, which will free space for the relocation process. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-20btrfs: rename delete_unused_bgs_mutex to reclaim_bgs_lockJohannes Thumshirn
As a preparation for extending the block group deletion use case, rename the unused_bgs_mutex to reclaim_bgs_lock. Reviewed-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-20btrfs: zoned: reset zones of relocated block groupsJohannes Thumshirn
When relocating a block group the freed up space is not discarded in one big block, but each extent is discarded on its own with -odisard=sync. For a zoned filesystem we need to discard the whole block group at once, so btrfs_discard_extent() will translate the discard into a REQ_OP_ZONE_RESET operation, which then resets the device's zone. Failure to reset the zone is not fatal error. Discussion about the approach and regarding transaction blocking: https://lore.kernel.org/linux-btrfs/CAL3q7H4SjS_d5rBepfTMhU8Th3bJzdmyYd0g4Z60yUgC_rC_ZA@mail.gmail.com/ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-20btrfs: more graceful errors/warnings on 32bit systems when reaching limitsQu Wenruo
Btrfs uses internally mapped u64 address space for all its metadata. Due to the page cache limit on 32bit systems, btrfs can't access metadata at or beyond (ULONG_MAX + 1) << PAGE_SHIFT. See how MAX_LFS_FILESIZE and page::index are defined. This is 16T for 4K page size while 256T for 64K page size. Users can have a filesystem which doesn't have metadata beyond the boundary at mount time, but later balance can cause it to create metadata beyond the boundary. And modification to MM layer is unrealistic just for such minor use case. We can't do more than to prevent mounting such filesystem or warn early when the numbers are still within the limits. To address such problem, this patch will introduce the following checks: - Mount time rejection This will reject any fs which has metadata chunk at or beyond the boundary. - Mount time early warning If there is any metadata chunk beyond 5/8th of the boundary, we do an early warning and hope the end user will see it. - Runtime extent buffer rejection If we're going to allocate an extent buffer at or beyond the boundary, reject such request with EOVERFLOW. This is definitely going to cause problems like transaction abort, but we have no better ways. - Runtime extent buffer early warning If an extent buffer beyond 5/8th of the max file size is allocated, do an early warning. Above error/warning message will only be printed once for each fs to reduce dmesg flood. If the mount is rejected, the filesystem will be mountable only on a 64bit host. Link: https://lore.kernel.org/linux-btrfs/1783f16d-7a28-80e6-4c32-fdf19b705ed0@gmx.com/ Reported-by: Erik Jensen <erikjensen@rkjnsn.net> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-20btrfs: zoned: fix unpaired block group unfreeze during device replaceFilipe Manana
When doing a device replace on a zoned filesystem, if we find a block group with ->to_copy == 0, we jump to the label 'done', which will result in later calling btrfs_unfreeze_block_group(), even though at this point we never called btrfs_freeze_block_group(). Since at this point we have neither turned the block group to RO mode nor made any progress, we don't need to jump to the label 'done'. So fix this by jumping instead to the label 'skip' and dropping our reference on the block group before the jump. Fixes: 78ce9fc269af6e ("btrfs: zoned: mark block groups to copy for device-replace") CC: stable@vger.kernel.org # 5.12 Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-20btrfs: fix race when picking most recent mod log operation for an old rootFilipe Manana
Commit dbcc7d57bffc0c ("btrfs: fix race when cloning extent buffer during rewind of an old root"), fixed a race when we need to rewind the extent buffer of an old root. It was caused by picking a new mod log operation for the extent buffer while getting a cloned extent buffer with an outdated number of items (off by -1), because we cloned the extent buffer without locking it first. However there is still another similar race, but in the opposite direction. The cloned extent buffer has a number of items that does not match the number of tree mod log operations that are going to be replayed. This is because right after we got the last (most recent) tree mod log operation to replay and before locking and cloning the extent buffer, another task adds a new pointer to the extent buffer, which results in adding a new tree mod log operation and incrementing the number of items in the extent buffer. So after cloning we have mismatch between the number of items in the extent buffer and the number of mod log operations we are going to apply to it. This results in hitting a BUG_ON() that produces the following stack trace: ------------[ cut here ]------------ kernel BUG at fs/btrfs/tree-mod-log.c:675! invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 3 PID: 4811 Comm: crawl_1215 Tainted: G W 5.12.0-7d1efdf501f8-misc-next+ #99 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:tree_mod_log_rewind+0x3b1/0x3c0 Code: 05 48 8d 74 10 (...) RSP: 0018:ffffc90001027090 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff8880a8514600 RCX: ffffffffaa9e59b6 RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff8880a851462c RBP: ffffc900010270e0 R08: 00000000000000c0 R09: ffffed1004333417 R10: ffff88802199a0b7 R11: ffffed1004333416 R12: 000000000000000e R13: ffff888135af8748 R14: ffff88818766ff00 R15: ffff8880a851462c FS: 00007f29acf62700(0000) GS:ffff8881f2200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0e6013f718 CR3: 000000010d42e003 CR4: 0000000000170ee0 Call Trace: btrfs_get_old_root+0x16a/0x5c0 ? lock_downgrade+0x400/0x400 btrfs_search_old_slot+0x192/0x520 ? btrfs_search_slot+0x1090/0x1090 ? free_extent_buffer.part.61+0xd7/0x140 ? free_extent_buffer+0x13/0x20 resolve_indirect_refs+0x3e9/0xfc0 ? lock_downgrade+0x400/0x400 ? __kasan_check_read+0x11/0x20 ? add_prelim_ref.part.11+0x150/0x150 ? lock_downgrade+0x400/0x400 ? __kasan_check_read+0x11/0x20 ? lock_acquired+0xbb/0x620 ? __kasan_check_write+0x14/0x20 ? do_raw_spin_unlock+0xa8/0x140 ? rb_insert_color+0x340/0x360 ? prelim_ref_insert+0x12d/0x430 find_parent_nodes+0x5c3/0x1830 ? stack_trace_save+0x87/0xb0 ? resolve_indirect_refs+0xfc0/0xfc0 ? fs_reclaim_acquire+0x67/0xf0 ? __kasan_check_read+0x11/0x20 ? lockdep_hardirqs_on_prepare+0x210/0x210 ? fs_reclaim_acquire+0x67/0xf0 ? __kasan_check_read+0x11/0x20 ? ___might_sleep+0x10f/0x1e0 ? __kasan_kmalloc+0x9d/0xd0 ? trace_hardirqs_on+0x55/0x120 btrfs_find_all_roots_safe+0x142/0x1e0 ? find_parent_nodes+0x1830/0x1830 ? trace_hardirqs_on+0x55/0x120 ? ulist_free+0x1f/0x30 ? btrfs_inode_flags_to_xflags+0x50/0x50 iterate_extent_inodes+0x20e/0x580 ? tree_backref_for_extent+0x230/0x230 ? release_extent_buffer+0x225/0x280 ? read_extent_buffer+0xdd/0x110 ? lock_downgrade+0x400/0x400 ? __kasan_check_read+0x11/0x20 ? lock_acquired+0xbb/0x620 ? __kasan_check_write+0x14/0x20 ? do_raw_spin_unlock+0xa8/0x140 ? _raw_spin_unlock+0x22/0x30 ? release_extent_buffer+0x225/0x280 iterate_inodes_from_logical+0x129/0x170 ? iterate_inodes_from_logical+0x129/0x170 ? btrfs_inode_flags_to_xflags+0x50/0x50 ? iterate_extent_inodes+0x580/0x580 ? __vmalloc_node+0x92/0xb0 ? init_data_container+0x34/0xb0 ? init_data_container+0x34/0xb0 ? kvmalloc_node+0x60/0x80 btrfs_ioctl_logical_to_ino+0x158/0x230 btrfs_ioctl+0x2038/0x4360 ? __kasan_check_write+0x14/0x20 ? mmput+0x3b/0x220 ? btrfs_ioctl_get_supported_features+0x30/0x30 ? __kasan_check_read+0x11/0x20 ? __kasan_check_read+0x11/0x20 ? lock_release+0xc8/0x650 ? __might_fault+0x64/0xd0 ? __kasan_check_read+0x11/0x20 ? lock_downgrade+0x400/0x400 ? lockdep_hardirqs_on_prepare+0x210/0x210 ? lockdep_hardirqs_on_prepare+0x13/0x210 ? _raw_spin_unlock_irqrestore+0x51/0x63 ? __kasan_check_read+0x11/0x20 ? do_vfs_ioctl+0xfc/0x9d0 ? ioctl_file_clone+0xe0/0xe0 ? lock_downgrade+0x400/0x400 ? lockdep_hardirqs_on_prepare+0x210/0x210 ? __kasan_check_read+0x11/0x20 ? lock_release+0xc8/0x650 ? __task_pid_nr_ns+0xd3/0x250 ? __kasan_check_read+0x11/0x20 ? __fget_files+0x160/0x230 ? __fget_light+0xf2/0x110 __x64_sys_ioctl+0xc3/0x100 do_syscall_64+0x37/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f29ae85b427 Code: 00 00 90 48 8b (...) RSP: 002b:00007f29acf5fcf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f29acf5ff40 RCX: 00007f29ae85b427 RDX: 00007f29acf5ff48 RSI: 00000000c038943b RDI: 0000000000000003 RBP: 0000000001000000 R08: 0000000000000000 R09: 00007f29acf60120 R10: 00005640d5fc7b00 R11: 0000000000000246 R12: 0000000000000003 R13: 00007f29acf5ff48 R14: 00007f29acf5ff40 R15: 00007f29acf5fef8 Modules linked in: ---[ end trace 85e5fce078dfbe04 ]--- (gdb) l *(tree_mod_log_rewind+0x3b1) 0xffffffff819e5b21 is in tree_mod_log_rewind (fs/btrfs/tree-mod-log.c:675). 670 * the modification. As we're going backwards, we do the 671 * opposite of each operation here. 672 */ 673 switch (tm->op) { 674 case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING: 675 BUG_ON(tm->slot < n); 676 fallthrough; 677 case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_MOVING: 678 case BTRFS_MOD_LOG_KEY_REMOVE: 679 btrfs_set_node_key(eb, &tm->key, tm->slot); (gdb) quit The following steps explain in more detail how it happens: 1) We have one tree mod log user (through fiemap or the logical ino ioctl), with a sequence number of 1, so we have fs_info->tree_mod_seq == 1. This is task A; 2) Another task is at ctree.c:balance_level() and we have eb X currently as the root of the tree, and we promote its single child, eb Y, as the new root. Then, at ctree.c:balance_level(), we call: ret = btrfs_tree_mod_log_insert_root(root->node, child, true); 3) At btrfs_tree_mod_log_insert_root() we create a tree mod log operation of type BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING, with a ->logical field pointing to ebX->start. We only have one item in eb X, so we create only one tree mod log operation, and store in the "tm_list" array; 4) Then, still at btrfs_tree_mod_log_insert_root(), we create a tree mod log element of operation type BTRFS_MOD_LOG_ROOT_REPLACE, ->logical set to ebY->start, ->old_root.logical set to ebX->start, ->old_root.level set to the level of eb X and ->generation set to the generation of eb X; 5) Then btrfs_tree_mod_log_insert_root() calls tree_mod_log_free_eb() with "tm_list" as argument. After that, tree_mod_log_free_eb() calls tree_mod_log_insert(). This inserts the mod log operation of type BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING from step 3 into the rbtree with a sequence number of 2 (and fs_info->tree_mod_seq set to 2); 6) Then, after inserting the "tm_list" single element into the tree mod log rbtree, the BTRFS_MOD_LOG_ROOT_REPLACE element is inserted, which gets the sequence number 3 (and fs_info->tree_mod_seq set to 3); 7) Back to ctree.c:balance_level(), we free eb X by calling btrfs_free_tree_block() on it. Because eb X was created in the current transaction, has no other references and writeback did not happen for it, we add it back to the free space cache/tree; 8) Later some other task B allocates the metadata extent from eb X, since it is marked as free space in the space cache/tree, and uses it as a node for some other btree; 9) The tree mod log user task calls btrfs_search_old_slot(), which calls btrfs_get_old_root(), and finally that calls tree_mod_log_oldest_root() with time_seq == 1 and eb_root == eb Y; 10) The first iteration of the while loop finds the tree mod log element with sequence number 3, for the logical address of eb Y and of type BTRFS_MOD_LOG_ROOT_REPLACE; 11) Because the operation type is BTRFS_MOD_LOG_ROOT_REPLACE, we don't break out of the loop, and set root_logical to point to tm->old_root.logical, which corresponds to the logical address of eb X; 12) On the next iteration of the while loop, the call to tree_mod_log_search_oldest() returns the smallest tree mod log element for the logical address of eb X, which has a sequence number of 2, an operation type of BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING and corresponds to the old slot 0 of eb X (eb X had only 1 item in it before being freed at step 7); 13) We then break out of the while loop and return the tree mod log operation of type BTRFS_MOD_LOG_ROOT_REPLACE (eb Y), and not the one for slot 0 of eb X, to btrfs_get_old_root(); 14) At btrfs_get_old_root(), we process the BTRFS_MOD_LOG_ROOT_REPLACE operation and set "logical" to the logical address of eb X, which was the old root. We then call tree_mod_log_search() passing it the logical address of eb X and time_seq == 1; 15) But before calling tree_mod_log_search(), task B locks eb X, adds a key to eb X, which results in adding a tree mod log operation of type BTRFS_MOD_LOG_KEY_ADD, with a sequence number of 4, to the tree mod log, and increments the number of items in eb X from 0 to 1. Now fs_info->tree_mod_seq has a value of 4; 16) Task A then calls tree_mod_log_search(), which returns the most recent tree mod log operation for eb X, which is the one just added by task B at the previous step, with a sequence number of 4, a type of BTRFS_MOD_LOG_KEY_ADD and for slot 0; 17) Before task A locks and clones eb X, task A adds another key to eb X, which results in adding a new BTRFS_MOD_LOG_KEY_ADD mod log operation, with a sequence number of 5, for slot 1 of eb X, increments the number of items in eb X from 1 to 2, and unlocks eb X. Now fs_info->tree_mod_seq has a value of 5; 18) Task A then locks eb X and clones it. The clone has a value of 2 for the number of items and the pointer "tm" points to the tree mod log operation with sequence number 4, not the most recent one with a sequence number of 5, so there is mismatch between the number of mod log operations that are going to be applied to the cloned version of eb X and the number of items in the clone; 19) Task A then calls tree_mod_log_rewind() with the clone of eb X, the tree mod log operation with sequence number 4 and a type of BTRFS_MOD_LOG_KEY_ADD, and time_seq == 1; 20) At tree_mod_log_rewind(), we set the local variable "n" with a value of 2, which is the number of items in the clone of eb X. Then in the first iteration of the while loop, we process the mod log operation with sequence number 4, which is targeted at slot 0 and has a type of BTRFS_MOD_LOG_KEY_ADD. This results in decrementing "n" from 2 to 1. Then we pick the next tree mod log operation for eb X, which is the tree mod log operation with a sequence number of 2, a type of BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING and for slot 0, it is the one added in step 5 to the tree mod log tree. We go back to the top of the loop to process this mod log operation, and because its slot is 0 and "n" has a value of 1, we hit the BUG_ON: (...) switch (tm->op) { case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING: BUG_ON(tm->slot < n); fallthrough; (...) Fix this by checking for a more recent tree mod log operation after locking and cloning the extent buffer of the old root node, and use it as the first operation to apply to the cloned extent buffer when rewinding it. Stable backport notes: due to moved code and renames, in =< 5.11 the change should be applied to ctree.c:get_old_root. Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Link: https://lore.kernel.org/linux-btrfs/20210404040732.GZ32440@hungrycats.org/ Fixes: 834328a8493079 ("Btrfs: tree mod log's old roots could still be part of the tree") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-20btrfs: fix metadata extent leak after failure to create subvolumeFilipe Manana
When creating a subvolume we allocate an extent buffer for its root node after starting a transaction. We setup a root item for the subvolume that points to that extent buffer and then attempt to insert the root item into the root tree - however if that fails, due to ENOMEM for example, we do not free the extent buffer previously allocated and we do not abort the transaction (as at that point we did nothing that can not be undone). This means that we effectively do not return the metadata extent back to the free space cache/tree and we leave a delayed reference for it which causes a metadata extent item to be added to the extent tree, in the next transaction commit, without having backreferences. When this happens 'btrfs check' reports the following: $ btrfs check /dev/sdi Opening filesystem to check... Checking filesystem on /dev/sdi UUID: dce2cb9d-025f-4b05-a4bf-cee0ad3785eb [1/7] checking root items [2/7] checking extents ref mismatch on [30425088 16384] extent item 1, found 0 backref 30425088 root 256 not referenced back 0x564a91c23d70 incorrect global backref count on 30425088 found 1 wanted 0 backpointer mismatch on [30425088 16384] owner ref check failed [30425088 16384] ERROR: errors found in extent allocation tree or chunk allocation [3/7] checking free space cache [4/7] checking fs roots [5/7] checking only csums items (without verifying data) [6/7] checking root refs [7/7] checking quota groups skipped (not enabled on this FS) found 212992 bytes used, error(s) found total csum bytes: 0 total tree bytes: 131072 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 124669 file data blocks allocated: 65536 referenced 65536 So fix this by freeing the metadata extent if btrfs_insert_root() returns an error. 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>
2021-04-19btrfs: handle remount to no compress during compressionQu Wenruo
[BUG] When running btrfs/071 with inode_need_compress() removed from compress_file_range(), we got the following crash: BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page Workqueue: btrfs-delalloc btrfs_work_helper [btrfs] RIP: 0010:compress_file_range+0x476/0x7b0 [btrfs] Call Trace: ? submit_compressed_extents+0x450/0x450 [btrfs] async_cow_start+0x16/0x40 [btrfs] btrfs_work_helper+0xf2/0x3e0 [btrfs] process_one_work+0x278/0x5e0 worker_thread+0x55/0x400 ? process_one_work+0x5e0/0x5e0 kthread+0x168/0x190 ? kthread_create_worker_on_cpu+0x70/0x70 ret_from_fork+0x22/0x30 ---[ end trace 65faf4eae941fa7d ]--- This is already after the patch "btrfs: inode: fix NULL pointer dereference if inode doesn't need compression." [CAUSE] @pages is firstly created by kcalloc() in compress_file_extent(): pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); Then passed to btrfs_compress_pages() to be utilized there: ret = btrfs_compress_pages(... pages, &nr_pages, ...); btrfs_compress_pages() will initialize each page as output, in zlib_compress_pages() we have: pages[nr_pages] = out_page; nr_pages++; Normally this is completely fine, but there is a special case which is in btrfs_compress_pages() itself: switch (type) { default: return -E2BIG; } In this case, we didn't modify @pages nor @out_pages, leaving them untouched, then when we cleanup pages, the we can hit NULL pointer dereference again: if (pages) { for (i = 0; i < nr_pages; i++) { WARN_ON(pages[i]->mapping); put_page(pages[i]); } ... } Since pages[i] are all initialized to zero, and btrfs_compress_pages() doesn't change them at all, accessing pages[i]->mapping would lead to NULL pointer dereference. This is not possible for current kernel, as we check inode_need_compress() before doing pages allocation. But if we're going to remove that inode_need_compress() in compress_file_extent(), then it's going to be a problem. [FIX] When btrfs_compress_pages() hits its default case, modify @out_pages to 0 to prevent such problem from happening. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212331 CC: stable@vger.kernel.org # 5.10+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: zoned: fail mount if the device does not support zone appendJohannes Thumshirn
For zoned btrfs, zone append is mandatory to write to a sequential write only zone, otherwise parallel writes to the same zone could result in unaligned write errors. If a zoned block device does not support zone append (e.g. a dm-crypt zoned device using a non-NULL IV cypher), fail to mount. CC: stable@vger.kernel.org # 5.12 Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: fix race between transaction aborts and fsyncs leading to use-after-freeFilipe Manana
There is a race between a task aborting a transaction during a commit, a task doing an fsync and the transaction kthread, which leads to an use-after-free of the log root tree. When this happens, it results in a stack trace like the following: BTRFS info (device dm-0): forced readonly BTRFS warning (device dm-0): Skipping commit of aborted transaction. BTRFS: error (device dm-0) in cleanup_transaction:1958: errno=-5 IO failure BTRFS warning (device dm-0): lost page write due to IO error on /dev/mapper/error-test (-5) BTRFS warning (device dm-0): Skipping commit of aborted transaction. BTRFS warning (device dm-0): direct IO failed ino 261 rw 0,0 sector 0xa4e8 len 4096 err no 10 BTRFS error (device dm-0): error writing primary super block to device 1 BTRFS warning (device dm-0): direct IO failed ino 261 rw 0,0 sector 0x12e000 len 4096 err no 10 BTRFS warning (device dm-0): direct IO failed ino 261 rw 0,0 sector 0x12e008 len 4096 err no 10 BTRFS warning (device dm-0): direct IO failed ino 261 rw 0,0 sector 0x12e010 len 4096 err no 10 BTRFS: error (device dm-0) in write_all_supers:4110: errno=-5 IO failure (1 errors while writing supers) BTRFS: error (device dm-0) in btrfs_sync_log:3308: errno=-5 IO failure general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b68: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI CPU: 2 PID: 2458471 Comm: fsstress Not tainted 5.12.0-rc5-btrfs-next-84 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 RIP: 0010:__mutex_lock+0x139/0xa40 Code: c0 74 19 (...) RSP: 0018:ffff9f18830d7b00 EFLAGS: 00010202 RAX: 6b6b6b6b6b6b6b68 RBX: 0000000000000001 RCX: 0000000000000002 RDX: ffffffffb9c54d13 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff9f18830d7bc0 R08: 0000000000000000 R09: 0000000000000000 R10: ffff9f18830d7be0 R11: 0000000000000001 R12: ffff8c6cd199c040 R13: ffff8c6c95821358 R14: 00000000fffffffb R15: ffff8c6cbcf01358 FS: 00007fa9140c2b80(0000) GS:ffff8c6fac600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa913d52000 CR3: 000000013d2b4003 CR4: 0000000000370ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? __btrfs_handle_fs_error+0xde/0x146 [btrfs] ? btrfs_sync_log+0x7c1/0xf20 [btrfs] ? btrfs_sync_log+0x7c1/0xf20 [btrfs] btrfs_sync_log+0x7c1/0xf20 [btrfs] btrfs_sync_file+0x40c/0x580 [btrfs] do_fsync+0x38/0x70 __x64_sys_fsync+0x10/0x20 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fa9142a55c3 Code: 8b 15 09 (...) RSP: 002b:00007fff26278d48 EFLAGS: 00000246 ORIG_RAX: 000000000000004a RAX: ffffffffffffffda RBX: 0000563c83cb4560 RCX: 00007fa9142a55c3 RDX: 00007fff26278cb0 RSI: 00007fff26278cb0 RDI: 0000000000000005 RBP: 0000000000000005 R08: 0000000000000001 R09: 00007fff26278d5c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000340 R13: 00007fff26278de0 R14: 00007fff26278d96 R15: 0000563c83ca57c0 Modules linked in: btrfs dm_zero dm_snapshot dm_thin_pool (...) ---[ end trace ee2f1b19327d791d ]--- The steps that lead to this crash are the following: 1) We are at transaction N; 2) We have two tasks with a transaction handle attached to transaction N. Task A and Task B. Task B is doing an fsync; 3) Task B is at btrfs_sync_log(), and has saved fs_info->log_root_tree into a local variable named 'log_root_tree' at the top of btrfs_sync_log(). Task B is about to call write_all_supers(), but before that... 4) Task A calls btrfs_commit_transaction(), and after it sets the transaction state to TRANS_STATE_COMMIT_START, an error happens before it waits for the transaction's 'num_writers' counter to reach a value of 1 (no one else attached to the transaction), so it jumps to the label "cleanup_transaction"; 5) Task A then calls cleanup_transaction(), where it aborts the transaction, setting BTRFS_FS_STATE_TRANS_ABORTED on fs_info->fs_state, setting the ->aborted field of the transaction and the handle to an errno value and also setting BTRFS_FS_STATE_ERROR on fs_info->fs_state. After that, at cleanup_transaction(), it deletes the transaction from the list of transactions (fs_info->trans_list), sets the transaction to the state TRANS_STATE_COMMIT_DOING and then waits for the number of writers to go down to 1, as it's currently 2 (1 for task A and 1 for task B); 6) The transaction kthread is running and sees that BTRFS_FS_STATE_ERROR is set in fs_info->fs_state, so it calls btrfs_cleanup_transaction(). There it sees the list fs_info->trans_list is empty, and then proceeds into calling btrfs_drop_all_logs(), which frees the log root tree with a call to btrfs_free_log_root_tree(); 7) Task B calls write_all_supers() and, shortly after, under the label 'out_wake_log_root', it deferences the pointer stored in 'log_root_tree', which was already freed in the previous step by the transaction kthread. This results in a use-after-free leading to a crash. Fix this by deleting the transaction from the list of transactions at cleanup_transaction() only after setting the transaction state to TRANS_STATE_COMMIT_DOING and waiting for all existing tasks that are attached to the transaction to release their transaction handles. This makes the transaction kthread wait for all the tasks attached to the transaction to be done with the transaction before dropping the log roots and doing other cleanups. Fixes: ef67963dac255b ("btrfs: drop logs when we've aborted a transaction") CC: stable@vger.kernel.org # 5.10+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: introduce submit_eb_subpage() to submit a subpage metadata pageQu Wenruo
The new function, submit_eb_subpage(), will submit all the dirty extent buffers in the page. The major difference between submit_eb_page() and submit_eb_subpage() is: - How to grab extent buffer Now we use find_extent_buffer_nospinlock() other than using page::private. All other different handling is already done in functions like lock_extent_buffer_for_io() and write_one_eb(). Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: make lock_extent_buffer_for_io() to be subpage compatibleQu Wenruo
For subpage metadata, we don't use page locking at all. So just skip the page locking part for subpage. The rest of the function can be reused. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: introduce write_one_subpage_eb() functionQu Wenruo
The new function, write_one_subpage_eb(), as a subroutine for subpage metadata write, will handle the extent buffer bio submission. The major differences between the new write_one_subpage_eb() and write_one_eb() is: - No page locking When entering write_one_subpage_eb() the page is no longer locked. We only lock the page for its status update, and unlock immediately. Now we completely rely on extent io tree locking. - Extra bitmap update along with page status update Now page dirty and writeback is controlled by btrfs_subpage::dirty_bitmap and btrfs_subpage::writeback_bitmap. They both follow the schema that any sector is dirty/writeback, then the full page gets dirty/writeback. - When to update the nr_written number Now we take a shortcut, if we have cleared the last dirty bit of the page, we update nr_written. This is not completely perfect, but should emulate the old behavior well enough. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: introduce end_bio_subpage_eb_writepage() functionQu Wenruo
The new function, end_bio_subpage_eb_writepage(), will handle the metadata writeback endio. The major differences involved are: - How to grab extent buffer Now page::private is a pointer to btrfs_subpage, we can no longer grab extent buffer directly. Thus we need to use the bv_offset to locate the extent buffer manually and iterate through the whole range. - Use btrfs_subpage_end_writeback() caller This helper will handle the subpage writeback for us. Since this function is executed under endio context, when grabbing extent buffers it can't grab eb->refs_lock as that lock is not designed to be grabbed under hardirq context. So here introduce a helper, find_extent_buffer_nolock(), for such situation, and convert find_extent_buffer() to use that helper. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: check return value of btrfs_commit_transaction in relocationJosef Bacik
There are a few places where we don't check the return value of btrfs_commit_transaction in relocation.c. Thankfully all these places have straightforward error handling, so simply change all of the sites at once. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: do proper error handling in merge_reloc_rootsJosef Bacik
We have a BUG_ON() if we get an error back from btrfs_get_fs_root(). This honestly should never fail, as at this point we have a solid coordination of fs root to reloc root, and these roots will all be in memory. But in the name of killing BUG_ON()'s remove these and handle the error condition properly, ASSERT()'ing for developers. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle extent corruption with select_one_root properlyJosef Bacik
In corruption cases we could have paths from a block up to no root at all, and thus we'll BUG_ON(!root) in select_one_root. Handle this by adding an ASSERT() for developers, and returning an error for normal users. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: cleanup error handling in prepare_to_mergeJosef Bacik
This probably can't happen even with a corrupt file system, because we would have failed much earlier on than here. However there's no reason we can't just check and bail out as appropriate, so do that and convert the correctness BUG_ON() to an ASSERT(). Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: do not panic in __add_reloc_rootJosef Bacik
If we have a duplicate entry for a reloc root then we could have fs corruption that resulted in a double allocation. Since this shouldn't happen unless there is corruption, add an ASSERT(ret != -EEXIST) to all of the callers of __add_reloc_root() to catch any logic mistakes for developers, otherwise normal error handling will happen for normal users. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle __add_reloc_root failures in btrfs_recover_relocationJosef Bacik
We can already handle errors appropriately from this function, deal with an error coming from __add_reloc_root appropriately. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: do proper error handling in create_reloc_inodeJosef Bacik
We already handle some errors in this function, and the callers do the correct error handling, so clean up the rest of the function to do the appropriate error handling. There's a little extra work that needs to be done here, as we create the inode item before we create the orphan item. We could potentially add the orphan item, but if we failed to create the inode item we would have to abort the transaction. Instead add a helper to delete the inode item we created in the case that we're unable to look up the inode (this would likely be caused by an ENOMEM), which if it succeeds means we can avoid a transaction abort in this particular error case. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: remove the extent item sanity checks in relocate_block_groupJosef Bacik
These checks are all taken care of for us by the tree checker code: - the flags don't change or are updated consistently - the v0 extent item format is invalid and caught in many other places too Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: tree-checker: check for BTRFS_BLOCK_FLAG_FULL_BACKREF being set ↵Josef Bacik
improperly We need to validate that a data extent item does not have the FULL_BACKREF flag set on its flags. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle extent reference errors in do_relocationJosef Bacik
We can already deal with errors appropriately from do_relocation, simply handle any errors that come from changing the refs at this point cleanly. We have to abort the transaction if we fail here as we've modified metadata at this point. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle errors in reference count manipulation in replace_pathJosef Bacik
If any of the reference count manipulation stuff fails in replace_path we need to abort the transaction, as we've modified the blocks already. We can simply break at this point and everything will be cleaned up. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle btrfs_search_slot failure in replace_pathJosef Bacik
The search can fail for various reasons, in case of errors there's no cleanup to be done so we can pass the error to the caller, adjusting for the case where the key is not found and search slot returns 1. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle btrfs_cow_block errors in replace_pathJosef Bacik
If we error out COWing the root node when doing a replace_path then we simply unlock and free the buffer and return the error. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: convert logic BUG_ON()'s in replace_path to ASSERT()'sJosef Bacik
A few BUG_ON()'s in replace_path are purely to keep us from making logical mistakes, so replace them with ASSERT()'s. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: do proper error handling in btrfs_update_reloc_rootJosef Bacik
We call btrfs_update_root in btrfs_update_reloc_root, which can fail for all sorts of reasons, including IO errors. Instead of panicing the box lets return the error, now that all callers properly handle those errors. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle btrfs_update_reloc_root failure in prepare_to_mergeJosef Bacik
btrfs_update_reloc_root will will return errors in the future, so handle an error properly in prepare_to_merge. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle btrfs_update_reloc_root failure in insert_dirty_subvolJosef Bacik
btrfs_update_reloc_root will will return errors in the future, so handle the error properly in insert_dirty_subvol. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: change insert_dirty_subvol to return errorsJosef Bacik
This will be able to return errors in the future, so change it to return an error and handle the errors appropriately. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle btrfs_update_reloc_root failure in commit_fs_rootsJosef Bacik
btrfs_update_reloc_root will will return errors in the future, so handle the error properly in commit_fs_roots. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: validate root::reloc_root after recording root in transJosef Bacik
If we fail to setup a root->reloc_root in a different thread that path will error out, however it still leaves root->reloc_root NULL but would still appear set up in the transaction. Subsequent calls to btrfs_record_root_in_transaction would succeed without attempting to create the reloc root, as the transid has already been updated. Handle this case by making sure we have a root->reloc_root set after a btrfs_record_root_in_transaction call so we don't end up dereferencing a NULL pointer. Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: do proper error handling in create_reloc_rootJosef Bacik
We do memory allocations here, read blocks from disk, all sorts of operations that could easily fail at any given point. Instead of panicing the box, simply return the error back up the chain, all callers at this point have proper error handling. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: have proper error handling in btrfs_init_reloc_rootJosef Bacik
create_reloc_root will return errors in the future, and __add_reloc_root can return ENOMEM or EEXIST, so handle these errors properly. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: return an error from btrfs_record_root_in_transJosef Bacik
We can create a reloc root when we record the root in the trans, which can fail for all sorts of different reasons. Propagate this error up the chain of callers. Future patches will fix the callers of btrfs_record_root_in_trans() to handle the error. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle record_root_in_trans failure in create_pending_snapshotJosef Bacik
record_root_in_trans can currently fail, so handle this failure properly. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle record_root_in_trans failure in btrfs_record_root_in_transJosef Bacik
record_root_in_trans can fail currently, handle this failure properly. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle record_root_in_trans failure in qgroup_account_snapshotJosef Bacik
record_root_in_trans can fail currently, so handle this failure properly. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle btrfs_record_root_in_trans failure in start_transactionJosef Bacik
btrfs_record_root_in_trans will return errors in the future, so handle the error properly in start_transaction. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle btrfs_record_root_in_trans failure in relocate_tree_blockJosef Bacik
btrfs_record_root_in_trans will return errors in the future, so handle the error properly in relocate_tree_block. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle btrfs_record_root_in_trans failure in create_subvolJosef Bacik
btrfs_record_root_in_trans will return errors in the future, so handle the error properly in create_subvol. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle btrfs_record_root_in_trans failure in btrfs_recover_log_treesJosef Bacik
btrfs_record_root_in_trans will return errors in the future, so handle the error properly in btrfs_recover_log_trees. This appears tricky, however we have a reference count on the destination root, so if this fails we need to continue on in the loop to make sure the proper cleanup is done. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle btrfs_record_root_in_trans failure in btrfs_delete_subvolumeJosef Bacik
btrfs_record_root_in_trans will return errors in the future, so handle the error properly in btrfs_delete_subvolume. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle btrfs_record_root_in_trans failure in btrfs_renameJosef Bacik
btrfs_record_root_in_trans will return errors in the future, so handle the error properly in btrfs_rename. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: handle btrfs_record_root_in_trans failure in btrfs_rename_exchangeJosef Bacik
btrfs_record_root_in_trans will return errors in the future, so handle the error properly in btrfs_rename_exchange. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: do proper error handling in record_reloc_root_in_transJosef Bacik
Generally speaking this shouldn't ever fail, the corresponding fs root for the reloc root will already be in memory, so we won't get ENOMEM here. However if there is no corresponding root for the reloc root then we could get ENOMEM when we try to allocate it or we could get ENOENT when we look it up and see that it doesn't exist. Convert these BUG_ON()'s into ASSERT()'s and add proper error handling for the case of corruption. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: check record_root_in_trans related failures in select_reloc_rootJosef Bacik
We will record the fs root or the reloc root in the trans in select_reloc_root. These will actually return errors in the following patches, so check their return value here and return it up the stack. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: convert BUG_ON()'s in select_reloc_root() to proper errorsJosef Bacik
We have several BUG_ON()'s in select_reloc_root() that can be tripped if there is an extent tree corruption. Convert these to ASSERT()'s, because if we hit it during testing it really is bad, or could indicate a problem with the backref walking code. However if users hit these problems it generally indicates corruption, I've hit a few machines in the fleet that trip over these with clearly corrupted extent trees, so be nice and print out an error message and return an error instead of bringing the whole box down. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>