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2024-09-10btrfs: convert lock_delalloc_pages() to take a folioJosef Bacik
Also rename lock_delalloc_pages => lock_delalloc_folios in the process, now that it exclusively works on folios. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert find_lock_delalloc_range() to use a folioJosef Bacik
Instead of passing in a page for locked_page, pass in the folio instead. We only use the folio itself to validate some range assumptions, and then pass it into other functions. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert writepage_delalloc() to take a folioJosef Bacik
We already use a folio heavily in this function, pass the folio in directly and use it everywhere, only passing the page down to functions that do not take a folio yet. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert btrfs_mark_ordered_io_finished() to take a folioJosef Bacik
We only need a folio now, make it take a folio as an argument and update all of the callers. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert btrfs_finish_ordered_extent() to take a folioJosef Bacik
The callers and callee's of this now all use folios, update it to take a folio as well. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert can_finish_ordered_extent() to use a folioJosef Bacik
Pass in a folio instead, and use a folio instead of a page. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: utilize folio more in btrfs_page_mkwrite()Josef Bacik
We already have a folio that we're using in btrfs_page_mkwrite, update the rest of the function to use folio everywhere else. This will make it easier on Willy when he drops page->index. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert add_ra_bio_pages() to use only foliosJosef Bacik
Willy is going to get rid of page->index, and add_ra_bio_pages uses page->index. Make his life easier by converting add_ra_bio_pages to use folios so that we are no longer using page->index. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert __extent_writepage() to be completely folio basedJosef Bacik
Now that we've gotten most of the helpers updated to only take a folio, update __extent_writepage to only deal in folios. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert extent_write_locked_range() to use foliosJosef Bacik
Instead of using pages for everything, find a folio and use that. This makes things a bit cleaner as a lot of the functions calls here all take folios. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert __extent_writepage_io() to take a folioJosef Bacik
__extent_writepage_io uses page everywhere, but a lot of these functions take a folio. Convert it to use the folio based helpers, and then change it to take a folio as an argument and update its callers. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: update the writepage tracepoint to take a folioJosef Bacik
Willy is wanting to get rid of page->index, convert the writepage tracepoint to take a folio so we can do folio->index instead of page->index. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert btrfs_do_readpage() to only use a folioJosef Bacik
Now that the callers and helpers mostly use folio, convert btrfs_do_readpage to take a folio, and rename it to btrfs_do_read_folio. Update all of the page stuff to use the folio based helpers instead. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert submit_extent_page() to use a folioJosef Bacik
The callers of this helper are going to be converted to using a folio, so adjust submit_extent_page to become submit_extent_folio and update it to use all the relevant folio helpers. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert begin_page_folio() to take a folio insteadJosef Bacik
This already uses a folio internally, change it to take a folio as an argument instead. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert end_page_read() to take a folioJosef Bacik
We have this helper function to set the page range uptodate once we're done reading it, as well as run fsverity against it. Half of these functions already take a folio, just rename this to end_folio_read and then rework it to take a folio instead, and update everything accordingly. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert btrfs_read_folio() to only use a folioJosef Bacik
Currently we're using the page for everything here. Convert this to use the folio helpers instead. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: convert btrfs_readahead() to only use folioJosef Bacik
We're the only user of readahead_page_batch(). Convert btrfs_readahead() to use the folio based helpers to do readahead. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: print message on device opening error during mountLi Zhang
[ENHANCEMENT] When mounting a btrfs filesystem, the filesystem opens the block device, and if this fails, there is no message about it. Print a message about it to help debugging. [TEST] I have a btrfs filesystem on three block devices, one of which is write-protected, so regular mounts fail, but there is no message in dmesg. /dev/vdb normal /dev/vdc write protected /dev/vdd normal Before patch: $ sudo mount /dev/vdb /mnt/ mount: mount(2) failed: no such file or directory $ sudo dmesg # Show only messages about missing block devices .... [ 352.947196] BTRFS error (device vdb): devid 2 uuid 4ee2c625-a3b2-4fe0-b411-756b23e08533 missing .... After patch: $ sudo mount /dev/vdb /mnt/ mount: mount(2) failed: no such file or directory $ sudo dmesg # Show bdev_file_open_by_path failed. .... [ 352.944328] BTRFS error: failed to open device for path /dev/vdc with flags 0x3: -13 [ 352.947196] BTRFS error (device vdb): missing devid 2 uuid 4ee2c625-a3b2-4fe0-b411-756b23e08533 .... Signed-off-by: Li Zhang <zhanglikernel@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: move uuid tree related code to uuid-tree.[ch]Qu Wenruo
Functions btrfs_uuid_scan_kthread() and btrfs_create_uuid_tree() are for UUID tree rescan and creation, it's not suitable for volumes.[ch]. Move them to uuid-tree.[ch] instead. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: reduce size and overhead of extent_map_block_end()Filipe Manana
At extent_map_block_end() we are calling the inline functions extent_map_block_start() and extent_map_block_len() multiple times, which results in expanding their code multiple times, increasing the compiled code size and repeating the computations those functions do. Improve this by caching their results in local variables. The size of the module before this change: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 1755770 163800 16920 1936490 1d8c6a fs/btrfs/btrfs.ko And after this change: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 1755656 163800 16920 1936376 1d8bf8 fs/btrfs/btrfs.ko Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Qu Wenruo <wqu@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>
2024-09-10btrfs: update stripe_extent delete loop assumptionsJohannes Thumshirn
btrfs_delete_raid_extent() was written under the assumption, that it's call-chain always passes a start, length tuple that matches a single extent. But btrfs_delete_raid_extent() is called by do_free_extent_accounting() which in turn is called by __btrfs_free_extent(). But this call-chain passes in a start address and a length that can possibly match multiple on-disk extents. To make this possible, we have to adjust the start and length of each btree node lookup, to not delete beyond the requested range. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: update stripe extents for existing logical addressesJohannes Thumshirn
Update a stripe extent in case of an already existing logical address, but with different physical addresses and/or device id instead of bailing out with EEXIST. This can happen i.e. in case of a device replace operation, where data extents get rewritten to a new disk. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-03btrfs: fix race between direct IO write and fsync when using same fdFilipe Manana
If we have 2 threads that are using the same file descriptor and one of them is doing direct IO writes while the other is doing fsync, we have a race where we can end up either: 1) Attempt a fsync without holding the inode's lock, triggering an assertion failures when assertions are enabled; 2) Do an invalid memory access from the fsync task because the file private points to memory allocated on stack by the direct IO task and it may be used by the fsync task after the stack was destroyed. The race happens like this: 1) A user space program opens a file descriptor with O_DIRECT; 2) The program spawns 2 threads using libpthread for example; 3) One of the threads uses the file descriptor to do direct IO writes, while the other calls fsync using the same file descriptor. 4) Call task A the thread doing direct IO writes and task B the thread doing fsyncs; 5) Task A does a direct IO write, and at btrfs_direct_write() sets the file's private to an on stack allocated private with the member 'fsync_skip_inode_lock' set to true; 6) Task B enters btrfs_sync_file() and sees that there's a private structure associated to the file which has 'fsync_skip_inode_lock' set to true, so it skips locking the inode's VFS lock; 7) Task A completes the direct IO write, and resets the file's private to NULL since it had no prior private and our private was stack allocated. Then it unlocks the inode's VFS lock; 8) Task B enters btrfs_get_ordered_extents_for_logging(), then the assertion that checks the inode's VFS lock is held fails, since task B never locked it and task A has already unlocked it. The stack trace produced is the following: assertion failed: inode_is_locked(&inode->vfs_inode), in fs/btrfs/ordered-data.c:983 ------------[ cut here ]------------ kernel BUG at fs/btrfs/ordered-data.c:983! Oops: invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 9 PID: 5072 Comm: worker Tainted: G U OE 6.10.5-1-default #1 openSUSE Tumbleweed 69f48d427608e1c09e60ea24c6c55e2ca1b049e8 Hardware name: Acer Predator PH315-52/Covini_CFS, BIOS V1.12 07/28/2020 RIP: 0010:btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs] Code: 50 d6 86 c0 e8 (...) RSP: 0018:ffff9e4a03dcfc78 EFLAGS: 00010246 RAX: 0000000000000054 RBX: ffff9078a9868e98 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff907dce4a7800 RDI: ffff907dce4a7800 RBP: ffff907805518800 R08: 0000000000000000 R09: ffff9e4a03dcfb38 R10: ffff9e4a03dcfb30 R11: 0000000000000003 R12: ffff907684ae7800 R13: 0000000000000001 R14: ffff90774646b600 R15: 0000000000000000 FS: 00007f04b96006c0(0000) GS:ffff907dce480000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f32acbfc000 CR3: 00000001fd4fa005 CR4: 00000000003726f0 Call Trace: <TASK> ? __die_body.cold+0x14/0x24 ? die+0x2e/0x50 ? do_trap+0xca/0x110 ? do_error_trap+0x6a/0x90 ? btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a] ? exc_invalid_op+0x50/0x70 ? btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a] ? asm_exc_invalid_op+0x1a/0x20 ? btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a] ? btrfs_get_ordered_extents_for_logging.cold+0x1f/0x42 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a] btrfs_sync_file+0x21a/0x4d0 [btrfs bb26272d49b4cdc847cf3f7faadd459b62caee9a] ? __seccomp_filter+0x31d/0x4f0 __x64_sys_fdatasync+0x4f/0x90 do_syscall_64+0x82/0x160 ? do_futex+0xcb/0x190 ? __x64_sys_futex+0x10e/0x1d0 ? switch_fpu_return+0x4f/0xd0 ? syscall_exit_to_user_mode+0x72/0x220 ? do_syscall_64+0x8e/0x160 ? syscall_exit_to_user_mode+0x72/0x220 ? do_syscall_64+0x8e/0x160 ? syscall_exit_to_user_mode+0x72/0x220 ? do_syscall_64+0x8e/0x160 ? syscall_exit_to_user_mode+0x72/0x220 ? do_syscall_64+0x8e/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e Another problem here is if task B grabs the private pointer and then uses it after task A has finished, since the private was allocated in the stack of task A, it results in some invalid memory access with a hard to predict result. This issue, triggering the assertion, was observed with QEMU workloads by two users in the Link tags below. Fix this by not relying on a file's private to pass information to fsync that it should skip locking the inode and instead pass this information through a special value stored in current->journal_info. This is safe because in the relevant section of the direct IO write path we are not holding a transaction handle, so current->journal_info is NULL. The following C program triggers the issue: $ cat repro.c /* Get the O_DIRECT definition. */ #ifndef _GNU_SOURCE #define _GNU_SOURCE #endif #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <stdint.h> #include <fcntl.h> #include <errno.h> #include <string.h> #include <pthread.h> static int fd; static ssize_t do_write(int fd, const void *buf, size_t count, off_t offset) { while (count > 0) { ssize_t ret; ret = pwrite(fd, buf, count, offset); if (ret < 0) { if (errno == EINTR) continue; return ret; } count -= ret; buf += ret; } return 0; } static void *fsync_loop(void *arg) { while (1) { int ret; ret = fsync(fd); if (ret != 0) { perror("Fsync failed"); exit(6); } } } int main(int argc, char *argv[]) { long pagesize; void *write_buf; pthread_t fsyncer; int ret; if (argc != 2) { fprintf(stderr, "Use: %s <file path>\n", argv[0]); return 1; } fd = open(argv[1], O_WRONLY | O_CREAT | O_TRUNC | O_DIRECT, 0666); if (fd == -1) { perror("Failed to open/create file"); return 1; } pagesize = sysconf(_SC_PAGE_SIZE); if (pagesize == -1) { perror("Failed to get page size"); return 2; } ret = posix_memalign(&write_buf, pagesize, pagesize); if (ret) { perror("Failed to allocate buffer"); return 3; } ret = pthread_create(&fsyncer, NULL, fsync_loop, NULL); if (ret != 0) { fprintf(stderr, "Failed to create writer thread: %d\n", ret); return 4; } while (1) { ret = do_write(fd, write_buf, pagesize, 0); if (ret != 0) { perror("Write failed"); exit(5); } } return 0; } $ mkfs.btrfs -f /dev/sdi $ mount /dev/sdi /mnt/sdi $ timeout 10 ./repro /mnt/sdi/foo Usually the race is triggered within less than 1 second. A test case for fstests will follow soon. Reported-by: Paulo Dias <paulo.miguel.dias@gmail.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=219187 Reported-by: Andreas Jahn <jahn-andi@web.de> Link: https://bugzilla.kernel.org/show_bug.cgi?id=219199 Reported-by: syzbot+4704b3cc972bd76024f1@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/00000000000044ff540620d7dee2@google.com/ Fixes: 939b656bc8ab ("btrfs: fix corruption after buffer fault in during direct IO append write") CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-02btrfs: zoned: handle broken write pointer on zonesNaohiro Aota
Btrfs rejects to mount a FS if it finds a block group with a broken write pointer (e.g, unequal write pointers on two zones of RAID1 block group). Since such case can happen easily with a power-loss or crash of a system, we need to handle the case more gently. Handle such block group by making it unallocatable, so that there will be no writes into it. That can be done by setting the allocation pointer at the end of allocating region (= block_group->zone_capacity). Then, existing code handle zone_unusable properly. Having proper zone_capacity is necessary for the change. So, set it as fast as possible. We cannot handle RAID0 and RAID10 case like this. But, they are anyway unable to read because of a missing stripe. Fixes: 265f7237dd25 ("btrfs: zoned: allow DUP on meta-data block groups") Fixes: 568220fa9657 ("btrfs: zoned: support RAID0/1/10 on top of raid stripe tree") CC: stable@vger.kernel.org # 6.1+ Reported-by: HAN Yuwei <hrx@bupt.moe> Cc: Xuefer <xuefer@gmail.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-02btrfs: qgroup: don't use extent changeset when not neededFedor Pchelkin
The local extent changeset is passed to clear_record_extent_bits() where it may have some additional memory dynamically allocated for ulist. When qgroup is disabled, the memory is leaked because in this case the changeset is not released upon __btrfs_qgroup_release_data() return. Since the recorded contents of the changeset are not used thereafter, just don't pass it. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Reported-by: syzbot+81670362c283f3dd889c@syzkaller.appspotmail.com Closes: https://lore.kernel.org/lkml/000000000000aa8c0c060ade165e@google.com Fixes: af0e2aab3b70 ("btrfs: qgroup: flush reservations during quota disable") CC: stable@vger.kernel.org # 6.10+ Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-29block: rework bio splittingChristoph Hellwig
The current setup with bio_may_exceed_limit and __bio_split_to_limits is a bit of a mess. Change it so that __bio_split_to_limits does all the work and is just a variant of bio_split_to_limits that returns nr_segs. This is done by inlining it and instead have the various bio_split_* helpers directly submit the potentially split bios. To support btrfs, the rw version has a lower level helper split out that just returns the offset to split. This turns out to nicely clean up the btrfs flow as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: David Sterba <dsterba@suse.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Tested-by: Hans Holmberg <hans.holmberg@wdc.com> Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com> Link: https://lore.kernel.org/r/20240826173820.1690925-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-08-27btrfs: fix uninitialized return value from btrfs_reclaim_sweep()Filipe Manana
The return variable 'ret' at btrfs_reclaim_sweep() is never assigned if none of the space infos is reclaimable (for example if periodic reclaim is disabled, which is the default), so we return an undefined value. This can be fixed my making btrfs_reclaim_sweep() not return any value as well as do_reclaim_sweep() because: 1) do_reclaim_sweep() always returns 0, so we can make it return void; 2) The only caller of btrfs_reclaim_sweep() (btrfs_reclaim_bgs()) doesn't care about its return value, and in its context there's nothing to do about any errors anyway. Therefore remove the return value from btrfs_reclaim_sweep() and do_reclaim_sweep(). Fixes: e4ca3932ae90 ("btrfs: periodic block_group reclaim") Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-27btrfs: fix a use-after-free when hitting errors inside btrfs_submit_chunk()Qu Wenruo
[BUG] There is an internal report that KASAN is reporting use-after-free, with the following backtrace: BUG: KASAN: slab-use-after-free in btrfs_check_read_bio+0xa68/0xb70 [btrfs] Read of size 4 at addr ffff8881117cec28 by task kworker/u16:2/45 CPU: 1 UID: 0 PID: 45 Comm: kworker/u16:2 Not tainted 6.11.0-rc2-next-20240805-default+ #76 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014 Workqueue: btrfs-endio btrfs_end_bio_work [btrfs] Call Trace: dump_stack_lvl+0x61/0x80 print_address_description.constprop.0+0x5e/0x2f0 print_report+0x118/0x216 kasan_report+0x11d/0x1f0 btrfs_check_read_bio+0xa68/0xb70 [btrfs] process_one_work+0xce0/0x12a0 worker_thread+0x717/0x1250 kthread+0x2e3/0x3c0 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x11/0x20 Allocated by task 20917: kasan_save_stack+0x37/0x60 kasan_save_track+0x10/0x30 __kasan_slab_alloc+0x7d/0x80 kmem_cache_alloc_noprof+0x16e/0x3e0 mempool_alloc_noprof+0x12e/0x310 bio_alloc_bioset+0x3f0/0x7a0 btrfs_bio_alloc+0x2e/0x50 [btrfs] submit_extent_page+0x4d1/0xdb0 [btrfs] btrfs_do_readpage+0x8b4/0x12a0 [btrfs] btrfs_readahead+0x29a/0x430 [btrfs] read_pages+0x1a7/0xc60 page_cache_ra_unbounded+0x2ad/0x560 filemap_get_pages+0x629/0xa20 filemap_read+0x335/0xbf0 vfs_read+0x790/0xcb0 ksys_read+0xfd/0x1d0 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Freed by task 20917: kasan_save_stack+0x37/0x60 kasan_save_track+0x10/0x30 kasan_save_free_info+0x37/0x50 __kasan_slab_free+0x4b/0x60 kmem_cache_free+0x214/0x5d0 bio_free+0xed/0x180 end_bbio_data_read+0x1cc/0x580 [btrfs] btrfs_submit_chunk+0x98d/0x1880 [btrfs] btrfs_submit_bio+0x33/0x70 [btrfs] submit_one_bio+0xd4/0x130 [btrfs] submit_extent_page+0x3ea/0xdb0 [btrfs] btrfs_do_readpage+0x8b4/0x12a0 [btrfs] btrfs_readahead+0x29a/0x430 [btrfs] read_pages+0x1a7/0xc60 page_cache_ra_unbounded+0x2ad/0x560 filemap_get_pages+0x629/0xa20 filemap_read+0x335/0xbf0 vfs_read+0x790/0xcb0 ksys_read+0xfd/0x1d0 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 [CAUSE] Although I cannot reproduce the error, the report itself is good enough to pin down the cause. The call trace is the regular endio workqueue context, but the free-by-task trace is showing that during btrfs_submit_chunk() we already hit a critical error, and is calling btrfs_bio_end_io() to error out. And the original endio function called bio_put() to free the whole bio. This means a double freeing thus causing use-after-free, e.g.: 1. Enter btrfs_submit_bio() with a read bio The read bio length is 128K, crossing two 64K stripes. 2. The first run of btrfs_submit_chunk() 2.1 Call btrfs_map_block(), which returns 64K 2.2 Call btrfs_split_bio() Now there are two bios, one referring to the first 64K, the other referring to the second 64K. 2.3 The first half is submitted. 3. The second run of btrfs_submit_chunk() 3.1 Call btrfs_map_block(), which by somehow failed Now we call btrfs_bio_end_io() to handle the error 3.2 btrfs_bio_end_io() calls the original endio function Which is end_bbio_data_read(), and it calls bio_put() for the original bio. Now the original bio is freed. 4. The submitted first 64K bio finished Now we call into btrfs_check_read_bio() and tries to advance the bio iter. But since the original bio (thus its iter) is already freed, we trigger the above use-after free. And even if the memory is not poisoned/corrupted, we will later call the original endio function, causing a double freeing. [FIX] Instead of calling btrfs_bio_end_io(), call btrfs_orig_bbio_end_io(), which has the extra check on split bios and do the proper refcounting for cloned bios. Furthermore there is already one extra btrfs_cleanup_bio() call, but that is duplicated to btrfs_orig_bbio_end_io() call, so remove that label completely. Reported-by: David Sterba <dsterba@suse.com> Fixes: 852eee62d31a ("btrfs: allow btrfs_submit_bio to split bios") CC: stable@vger.kernel.org # 6.6+ 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>
2024-08-26btrfs: initialize last_extent_end to fix -Wmaybe-uninitialized warning in ↵David Sterba
extent_fiemap() There's a warning (probably on some older compiler version): fs/btrfs/fiemap.c: warning: 'last_extent_end' may be used uninitialized in this function [-Wmaybe-uninitialized]: => 822:19 Initialize the variable to 0 although it's not necessary as it's either properly set or not used after an error. The called function is in the same file so this is a false alert but we want to fix all -Wmaybe-uninitialized reports. Link: https://lore.kernel.org/all/20240819070639.2558629-1-geert@linux-m68k.org/ Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-25btrfs: run delayed iputs when flushing delallocJosef Bacik
We have transient failures with btrfs/301, specifically in the part where we do for i in $(seq 0 10); do write 50m to file rm -f file done Sometimes this will result in a transient quota error, and it's because sometimes we start writeback on the file which results in a delayed iput, and thus the rm doesn't actually clean the file up. When we're flushing the quota space we need to run the delayed iputs to make sure all the unlinks that we think have completed have actually completed. This removes the small window where we could fail to find enough space in our quota. CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-16btrfs: only enable extent map shrinker for DEBUG buildsQu Wenruo
Although there are several patches improving the extent map shrinker, there are still reports of too frequent shrinker behavior, taking too much CPU for the kswapd process. So let's only enable extent shrinker for now, until we got more comprehensive understanding and a better solution. Link: https://lore.kernel.org/linux-btrfs/3df4acd616a07ef4d2dc6bad668701504b412ffc.camel@intelfx.name/ Link: https://lore.kernel.org/linux-btrfs/c30fd6b3-ca7a-4759-8a53-d42878bf84f7@gmail.com/ Fixes: 956a17d9d050 ("btrfs: add a shrinker for extent maps") CC: stable@vger.kernel.org # 6.10+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-15btrfs: zoned: properly take lock to read/update block group's zoned variablesNaohiro Aota
__btrfs_add_free_space_zoned() references and modifies bg's alloc_offset, ro, and zone_unusable, but without taking the lock. It is mostly safe because they monotonically increase (at least for now) and this function is mostly called by a transaction commit, which is serialized by itself. Still, taking the lock is a safer and correct option and I'm going to add a change to reset zone_unusable while a block group is still alive. So, add locking around the operations. Fixes: 169e0da91a21 ("btrfs: zoned: track unusable bytes for zones") CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-15btrfs: tree-checker: add dev extent item checksQu Wenruo
[REPORT] There is a corruption report that btrfs refused to mount a fs that has overlapping dev extents: BTRFS error (device sdc): dev extent devid 4 physical offset 14263979671552 overlap with previous dev extent end 14263980982272 BTRFS error (device sdc): failed to verify dev extents against chunks: -117 BTRFS error (device sdc): open_ctree failed [CAUSE] The direct cause is very obvious, there is a bad dev extent item with incorrect length. With btrfs check reporting two overlapping extents, the second one shows some clue on the cause: ERROR: dev extent devid 4 offset 14263979671552 len 6488064 overlap with previous dev extent end 14263980982272 ERROR: dev extent devid 13 offset 2257707008000 len 6488064 overlap with previous dev extent end 2257707270144 ERROR: errors found in extent allocation tree or chunk allocation The second one looks like a bitflip happened during new chunk allocation: hex(2257707008000) = 0x20da9d30000 hex(2257707270144) = 0x20da9d70000 diff = 0x00000040000 So it looks like a bitflip happened during new dev extent allocation, resulting the second overlap. Currently we only do the dev-extent verification at mount time, but if the corruption is caused by memory bitflip, we really want to catch it before writing the corruption to the storage. Furthermore the dev extent items has the following key definition: (<device id> DEV_EXTENT <physical offset>) Thus we can not just rely on the generic key order check to make sure there is no overlapping. [ENHANCEMENT] Introduce dedicated dev extent checks, including: - Fixed member checks * chunk_tree should always be BTRFS_CHUNK_TREE_OBJECTID (3) * chunk_objectid should always be BTRFS_FIRST_CHUNK_CHUNK_TREE_OBJECTID (256) - Alignment checks * chunk_offset should be aligned to sectorsize * length should be aligned to sectorsize * key.offset should be aligned to sectorsize - Overlap checks If the previous key is also a dev-extent item, with the same device id, make sure we do not overlap with the previous dev extent. Reported: Stefan N <stefannnau@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CA+W5K0rSO3koYTo=nzxxTm1-Pdu1HYgVxEpgJ=aGc7d=E8mGEg@mail.gmail.com/ CC: stable@vger.kernel.org # 5.10+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-15btrfs: update target inode's ctime on unlinkJeff Layton
Unlink changes the link count on the target inode. POSIX mandates that the ctime must also change when this occurs. According to https://pubs.opengroup.org/onlinepubs/9699919799/functions/unlink.html: "Upon successful completion, unlink() shall mark for update the last data modification and last file status change timestamps of the parent directory. Also, if the file's link count is not 0, the last file status change timestamp of the file shall be marked for update." Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: David Sterba <dsterba@suse.com> [ add link to the opengroup docs ] Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-15btrfs: send: annotate struct name_cache_entry with __counted_by()Thorsten Blum
Add the __counted_by compiler attribute to the flexible array member name to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE. Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-13btrfs: fix invalid mapping of extent xarray stateNaohiro Aota
In __extent_writepage_io(), we call btrfs_set_range_writeback() -> folio_start_writeback(), which clears PAGECACHE_TAG_DIRTY mark from the mapping xarray if the folio is not dirty. This worked fine before commit 97713b1a2ced ("btrfs: do not clear page dirty inside extent_write_locked_range()"). After the commit, however, the folio is still dirty at this point, so the mapping DIRTY tag is not cleared anymore. Then, __extent_writepage_io() calls btrfs_folio_clear_dirty() to clear the folio's dirty flag. That results in the page being unlocked with a "strange" state. The page is not PageDirty, but the mapping tag is set as PAGECACHE_TAG_DIRTY. This strange state looks like causing a hang with a call trace below when running fstests generic/091 on a null_blk device. It is waiting for a folio lock. While I don't have an exact relation between this hang and the strange state, fixing the state also fixes the hang. And, that state is worth fixing anyway. This commit reorders btrfs_folio_clear_dirty() and btrfs_set_range_writeback() in __extent_writepage_io(), so that the PAGECACHE_TAG_DIRTY tag is properly removed from the xarray. [464.274] task:fsx state:D stack:0 pid:3034 tgid:3034 ppid:2853 flags:0x00004002 [464.286] Call Trace: [464.291] <TASK> [464.295] __schedule+0x10ed/0x6260 [464.301] ? __pfx___blk_flush_plug+0x10/0x10 [464.308] ? __submit_bio+0x37c/0x450 [464.314] ? __pfx___schedule+0x10/0x10 [464.321] ? lock_release+0x567/0x790 [464.327] ? __pfx_lock_acquire+0x10/0x10 [464.334] ? __pfx_lock_release+0x10/0x10 [464.340] ? __pfx_lock_acquire+0x10/0x10 [464.347] ? __pfx_lock_release+0x10/0x10 [464.353] ? do_raw_spin_lock+0x12e/0x270 [464.360] schedule+0xdf/0x3b0 [464.365] io_schedule+0x8f/0xf0 [464.371] folio_wait_bit_common+0x2ca/0x6d0 [464.378] ? folio_wait_bit_common+0x1cc/0x6d0 [464.385] ? __pfx_folio_wait_bit_common+0x10/0x10 [464.392] ? __pfx_filemap_get_folios_tag+0x10/0x10 [464.400] ? __pfx_wake_page_function+0x10/0x10 [464.407] ? __pfx___might_resched+0x10/0x10 [464.414] ? do_raw_spin_unlock+0x58/0x1f0 [464.420] extent_write_cache_pages+0xe49/0x1620 [btrfs] [464.428] ? lock_acquire+0x435/0x500 [464.435] ? __pfx_extent_write_cache_pages+0x10/0x10 [btrfs] [464.443] ? btrfs_do_write_iter+0x493/0x640 [btrfs] [464.451] ? orc_find.part.0+0x1d4/0x380 [464.457] ? __pfx_lock_release+0x10/0x10 [464.464] ? __pfx_lock_release+0x10/0x10 [464.471] ? btrfs_do_write_iter+0x493/0x640 [btrfs] [464.478] btrfs_writepages+0x1cc/0x460 [btrfs] [464.485] ? __pfx_btrfs_writepages+0x10/0x10 [btrfs] [464.493] ? is_bpf_text_address+0x6e/0x100 [464.500] ? kernel_text_address+0x145/0x160 [464.507] ? unwind_get_return_address+0x5e/0xa0 [464.514] ? arch_stack_walk+0xac/0x100 [464.521] do_writepages+0x176/0x780 [464.527] ? lock_release+0x567/0x790 [464.533] ? __pfx_do_writepages+0x10/0x10 [464.540] ? __pfx_lock_acquire+0x10/0x10 [464.546] ? __pfx_stack_trace_save+0x10/0x10 [464.553] ? do_raw_spin_lock+0x12e/0x270 [464.560] ? do_raw_spin_unlock+0x58/0x1f0 [464.566] ? _raw_spin_unlock+0x23/0x40 [464.573] ? wbc_attach_and_unlock_inode+0x3da/0x7d0 [464.580] filemap_fdatawrite_wbc+0x113/0x180 [464.587] ? prepare_pages.constprop.0+0x13c/0x5c0 [btrfs] [464.596] __filemap_fdatawrite_range+0xaf/0xf0 [464.603] ? __pfx___filemap_fdatawrite_range+0x10/0x10 [464.611] ? trace_irq_enable.constprop.0+0xce/0x110 [464.618] ? kasan_quarantine_put+0xd7/0x1e0 [464.625] btrfs_start_ordered_extent+0x46f/0x570 [btrfs] [464.633] ? __pfx_btrfs_start_ordered_extent+0x10/0x10 [btrfs] [464.642] ? __clear_extent_bit+0x2c0/0x9d0 [btrfs] [464.650] btrfs_lock_and_flush_ordered_range+0xc6/0x180 [btrfs] [464.659] ? __pfx_btrfs_lock_and_flush_ordered_range+0x10/0x10 [btrfs] [464.669] btrfs_read_folio+0x12a/0x1d0 [btrfs] [464.676] ? __pfx_btrfs_read_folio+0x10/0x10 [btrfs] [464.684] ? __pfx_filemap_add_folio+0x10/0x10 [464.691] ? __pfx___might_resched+0x10/0x10 [464.698] ? __filemap_get_folio+0x1c5/0x450 [464.705] prepare_uptodate_page+0x12e/0x4d0 [btrfs] [464.713] prepare_pages.constprop.0+0x13c/0x5c0 [btrfs] [464.721] ? fault_in_iov_iter_readable+0xd2/0x240 [464.729] btrfs_buffered_write+0x5bd/0x12f0 [btrfs] [464.737] ? __pfx_btrfs_buffered_write+0x10/0x10 [btrfs] [464.745] ? __pfx_lock_release+0x10/0x10 [464.752] ? generic_write_checks+0x275/0x400 [464.759] ? down_write+0x118/0x1f0 [464.765] ? up_write+0x19b/0x500 [464.770] btrfs_direct_write+0x731/0xba0 [btrfs] [464.778] ? __pfx_btrfs_direct_write+0x10/0x10 [btrfs] [464.785] ? __pfx___might_resched+0x10/0x10 [464.792] ? lock_acquire+0x435/0x500 [464.798] ? lock_acquire+0x435/0x500 [464.804] btrfs_do_write_iter+0x494/0x640 [btrfs] [464.811] ? __pfx_btrfs_do_write_iter+0x10/0x10 [btrfs] [464.819] ? __pfx___might_resched+0x10/0x10 [464.825] ? rw_verify_area+0x6d/0x590 [464.831] vfs_write+0x5d7/0xf50 [464.837] ? __might_fault+0x9d/0x120 [464.843] ? __pfx_vfs_write+0x10/0x10 [464.849] ? btrfs_file_llseek+0xb1/0xfb0 [btrfs] [464.856] ? lock_release+0x567/0x790 [464.862] ksys_write+0xfb/0x1d0 [464.867] ? __pfx_ksys_write+0x10/0x10 [464.873] ? _raw_spin_unlock+0x23/0x40 [464.879] ? btrfs_getattr+0x4af/0x670 [btrfs] [464.886] ? vfs_getattr_nosec+0x79/0x340 [464.892] do_syscall_64+0x95/0x180 [464.898] ? __do_sys_newfstat+0xde/0xf0 [464.904] ? __pfx___do_sys_newfstat+0x10/0x10 [464.911] ? trace_irq_enable.constprop.0+0xce/0x110 [464.918] ? syscall_exit_to_user_mode+0xac/0x2a0 [464.925] ? do_syscall_64+0xa1/0x180 [464.931] ? trace_irq_enable.constprop.0+0xce/0x110 [464.939] ? trace_irq_enable.constprop.0+0xce/0x110 [464.946] ? syscall_exit_to_user_mode+0xac/0x2a0 [464.953] ? btrfs_file_llseek+0xb1/0xfb0 [btrfs] [464.960] ? do_syscall_64+0xa1/0x180 [464.966] ? btrfs_file_llseek+0xb1/0xfb0 [btrfs] [464.973] ? trace_irq_enable.constprop.0+0xce/0x110 [464.980] ? syscall_exit_to_user_mode+0xac/0x2a0 [464.987] ? __pfx_btrfs_file_llseek+0x10/0x10 [btrfs] [464.995] ? trace_irq_enable.constprop.0+0xce/0x110 [465.002] ? __pfx_btrfs_file_llseek+0x10/0x10 [btrfs] [465.010] ? do_syscall_64+0xa1/0x180 [465.016] ? lock_release+0x567/0x790 [465.022] ? __pfx_lock_acquire+0x10/0x10 [465.028] ? __pfx_lock_release+0x10/0x10 [465.034] ? trace_irq_enable.constprop.0+0xce/0x110 [465.042] ? syscall_exit_to_user_mode+0xac/0x2a0 [465.049] ? do_syscall_64+0xa1/0x180 [465.055] ? syscall_exit_to_user_mode+0xac/0x2a0 [465.062] ? do_syscall_64+0xa1/0x180 [465.068] ? syscall_exit_to_user_mode+0xac/0x2a0 [465.075] ? do_syscall_64+0xa1/0x180 [465.081] ? clear_bhb_loop+0x25/0x80 [465.087] ? clear_bhb_loop+0x25/0x80 [465.093] ? clear_bhb_loop+0x25/0x80 [465.099] entry_SYSCALL_64_after_hwframe+0x76/0x7e [465.106] RIP: 0033:0x7f093b8ee784 [465.111] RSP: 002b:00007ffc29d31b28 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 [465.122] RAX: ffffffffffffffda RBX: 0000000000006000 RCX: 00007f093b8ee784 [465.131] RDX: 000000000001de00 RSI: 00007f093b6ed200 RDI: 0000000000000003 [465.141] RBP: 000000000001de00 R08: 0000000000006000 R09: 0000000000000000 [465.150] R10: 0000000000023e00 R11: 0000000000000202 R12: 0000000000006000 [465.160] R13: 0000000000023e00 R14: 0000000000023e00 R15: 0000000000000001 [465.170] </TASK> [465.174] INFO: lockdep is turned off. Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com> Fixes: 97713b1a2ced ("btrfs: do not clear page dirty inside extent_write_locked_range()") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-13btrfs: send: allow cloning non-aligned extent if it ends at i_sizeFilipe Manana
If we a find that an extent is shared but its end offset is not sector size aligned, then we don't clone it and issue write operations instead. This is because the reflink (remap_file_range) operation does not allow to clone unaligned ranges, except if the end offset of the range matches the i_size of the source and destination files (and the start offset is sector size aligned). While this is not incorrect because send can only guarantee that a file has the same data in the source and destination snapshots, it's not optimal and generates confusion and surprising behaviour for users. For example, running this test: $ cat test.sh #!/bin/bash DEV=/dev/sdi MNT=/mnt/sdi mkfs.btrfs -f $DEV mount $DEV $MNT # Use a file size not aligned to any possible sector size. file_size=$((1 * 1024 * 1024 + 5)) # 1MB + 5 bytes dd if=/dev/random of=$MNT/foo bs=$file_size count=1 cp --reflink=always $MNT/foo $MNT/bar btrfs subvolume snapshot -r $MNT/ $MNT/snap rm -f /tmp/send-test btrfs send -f /tmp/send-test $MNT/snap umount $MNT mkfs.btrfs -f $DEV mount $DEV $MNT btrfs receive -vv -f /tmp/send-test $MNT xfs_io -r -c "fiemap -v" $MNT/snap/bar umount $MNT Gives the following result: (...) mkfile o258-7-0 rename o258-7-0 -> bar write bar - offset=0 length=49152 write bar - offset=49152 length=49152 write bar - offset=98304 length=49152 write bar - offset=147456 length=49152 write bar - offset=196608 length=49152 write bar - offset=245760 length=49152 write bar - offset=294912 length=49152 write bar - offset=344064 length=49152 write bar - offset=393216 length=49152 write bar - offset=442368 length=49152 write bar - offset=491520 length=49152 write bar - offset=540672 length=49152 write bar - offset=589824 length=49152 write bar - offset=638976 length=49152 write bar - offset=688128 length=49152 write bar - offset=737280 length=49152 write bar - offset=786432 length=49152 write bar - offset=835584 length=49152 write bar - offset=884736 length=49152 write bar - offset=933888 length=49152 write bar - offset=983040 length=49152 write bar - offset=1032192 length=16389 chown bar - uid=0, gid=0 chmod bar - mode=0644 utimes bar utimes BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=06d640da-9ca1-604c-b87c-3375175a8eb3, stransid=7 /mnt/sdi/snap/bar: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..2055]: 26624..28679 2056 0x1 There's no clone operation to clone extents from the file foo into file bar and fiemap confirms there's no shared flag (0x2000). So update send_write_or_clone() so that it proceeds with cloning if the source and destination ranges end at the i_size of the respective files. After this changes the result of the test is: (...) mkfile o258-7-0 rename o258-7-0 -> bar clone bar - source=foo source offset=0 offset=0 length=1048581 chown bar - uid=0, gid=0 chmod bar - mode=0644 utimes bar utimes BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=582420f3-ea7d-564e-bbe5-ce440d622190, stransid=7 /mnt/sdi/snap/bar: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..2055]: 26624..28679 2056 0x2001 A test case for fstests will also follow up soon. Link: https://github.com/kdave/btrfs-progs/issues/572#issuecomment-2282841416 CC: stable@vger.kernel.org # 5.10+ Reviewed-by: Qu Wenruo <wqu@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>
2024-08-13btrfs: only run the extent map shrinker from kswapd tasksFilipe Manana
Currently the extent map shrinker can be run by any task when attempting to allocate memory and there's enough memory pressure to trigger it. To avoid too much latency we stop iterating over extent maps and removing them once the task needs to reschedule. This logic was introduced in commit b3ebb9b7e92a ("btrfs: stop extent map shrinker if reschedule is needed"). While that solved high latency problems for some use cases, it's still not enough because with a too high number of tasks entering the extent map shrinker code, either due to memory allocations or because they are a kswapd task, we end up having a very high level of contention on some spin locks, namely: 1) The fs_info->fs_roots_radix_lock spin lock, which we need to find roots to iterate over their inodes; 2) The spin lock of the xarray used to track open inodes for a root (struct btrfs_root::inodes) - on 6.10 kernels and below, it used to be a red black tree and the spin lock was root->inode_lock; 3) The fs_info->delayed_iput_lock spin lock since the shrinker adds delayed iputs (calls btrfs_add_delayed_iput()). Instead of allowing the extent map shrinker to be run by any task, make it run only by kswapd tasks. This still solves the problem of running into OOM situations due to an unbounded extent map creation, which is simple to trigger by direct IO writes, as described in the changelog of commit 956a17d9d050 ("btrfs: add a shrinker for extent maps"), and by a similar case when doing buffered IO on files with a very large number of holes (keeping the file open and creating many holes, whose extent maps are only released when the file is closed). Reported-by: kzd <kzd@56709.net> Link: https://bugzilla.kernel.org/show_bug.cgi?id=219121 Reported-by: Octavia Togami <octavia.togami@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CAHPNGSSt-a4ZZWrtJdVyYnJFscFjP9S7rMcvEMaNSpR556DdLA@mail.gmail.com/ Fixes: 956a17d9d050 ("btrfs: add a shrinker for extent maps") CC: stable@vger.kernel.org # 6.10+ Tested-by: kzd <kzd@56709.net> Tested-by: Octavia Togami <octavia.togami@gmail.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-13btrfs: tree-checker: reject BTRFS_FT_UNKNOWN dir typeQu Wenruo
[REPORT] There is a bug report that kernel is rejecting a mismatching inode mode and its dir item: [ 1881.553937] BTRFS critical (device dm-0): inode mode mismatch with dir: inode mode=040700 btrfs type=2 dir type=0 [CAUSE] It looks like the inode mode is correct, while the dir item type 0 is BTRFS_FT_UNKNOWN, which should not be generated by btrfs at all. This may be caused by a memory bit flip. [ENHANCEMENT] Although tree-checker is not able to do any cross-leaf verification, for this particular case we can at least reject any dir type with BTRFS_FT_UNKNOWN. So here we enhance the dir type check from [0, BTRFS_FT_MAX), to (0, BTRFS_FT_MAX). Although the existing corruption can not be fixed just by such enhanced checking, it should prevent the same 0x2->0x0 bitflip for dir type to reach disk in the future. Reported-by: Kota <nospam@kota.moe> Link: https://lore.kernel.org/linux-btrfs/CACsxjPYnQF9ZF-0OhH16dAx50=BXXOcP74MxBc3BG+xae4vTTw@mail.gmail.com/ CC: stable@vger.kernel.org # 5.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-13btrfs: check delayed refs when we're checking if a ref existsJosef Bacik
In the patch 78c52d9eb6b7 ("btrfs: check for refs on snapshot delete resume") I added some code to handle file systems that had been corrupted by a bug that incorrectly skipped updating the drop progress key while dropping a snapshot. This code would check to see if we had already deleted our reference for a child block, and skip the deletion if we had already. Unfortunately there is a bug, as the check would only check the on-disk references. I made an incorrect assumption that blocks in an already deleted snapshot that was having the deletion resume on mount wouldn't be modified. If we have 2 pending deleted snapshots that share blocks, we can easily modify the rules for a block. Take the following example subvolume a exists, and subvolume b is a snapshot of subvolume a. They share references to block 1. Block 1 will have 2 full references, one for subvolume a and one for subvolume b, and it belongs to subvolume a (btrfs_header_owner(block 1) == subvolume a). When deleting subvolume a, we will drop our full reference for block 1, and because we are the owner we will drop our full reference for all of block 1's children, convert block 1 to FULL BACKREF, and add a shared reference to all of block 1's children. Then we will start the snapshot deletion of subvolume b. We look up the extent info for block 1, which checks delayed refs and tells us that FULL BACKREF is set, so sets parent to the bytenr of block 1. However because this is a resumed snapshot deletion, we call into check_ref_exists(). Because check_ref_exists() only looks at the disk, it doesn't find the shared backref for the child of block 1, and thus returns 0 and we skip deleting the reference for the child of block 1 and continue. This orphans the child of block 1. The fix is to lookup the delayed refs, similar to what we do in btrfs_lookup_extent_info(). However we only care about whether the reference exists or not. If we fail to find our reference on disk, go look up the bytenr in the delayed refs, and if it exists look for an existing ref in the delayed ref head. If that exists then we know we can delete the reference safely and carry on. If it doesn't exist we know we have to skip over this block. This bug has existed since I introduced this fix, however requires having multiple deleted snapshots pending when we unmount. We noticed this in production because our shutdown path stops the container on the system, which deletes a bunch of subvolumes, and then reboots the box. This gives us plenty of opportunities to hit this issue. Looking at the history we've seen this occasionally in production, but we had a big spike recently thanks to faster machines getting jobs with multiple subvolumes in the job. Chris Mason wrote a reproducer which does the following mount /dev/nvme4n1 /btrfs btrfs subvol create /btrfs/s1 simoop -E -f 4k -n 200000 -z /btrfs/s1 while(true) ; do btrfs subvol snap /btrfs/s1 /btrfs/s2 simoop -f 4k -n 200000 -r 10 -z /btrfs/s2 btrfs subvol snap /btrfs/s2 /btrfs/s3 btrfs balance start -dusage=80 /btrfs btrfs subvol del /btrfs/s2 /btrfs/s3 umount /btrfs btrfsck /dev/nvme4n1 || exit 1 mount /dev/nvme4n1 /btrfs done On the second loop this would fail consistently, with my patch it has been running for hours and hasn't failed. I also used dm-log-writes to capture the state of the failure so I could debug the problem. Using the existing failure case to test my patch validated that it fixes the problem. Fixes: 78c52d9eb6b7 ("btrfs: check for refs on snapshot delete resume") CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-12introduce fd_file(), convert all accessors to it.Al Viro
For any changes of struct fd representation we need to turn existing accesses to fields into calls of wrappers. Accesses to struct fd::flags are very few (3 in linux/file.h, 1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in explicit initializers). Those can be dealt with in the commit converting to new layout; accesses to struct fd::file are too many for that. This commit converts (almost) all of f.file to fd_file(f). It's not entirely mechanical ('file' is used as a member name more than just in struct fd) and it does not even attempt to distinguish the uses in pointer context from those in boolean context; the latter will be eventually turned into a separate helper (fd_empty()). NOTE: mass conversion to fd_empty(), tempting as it might be, is a bad idea; better do that piecewise in commit that convert from fdget...() to CLASS(...). [conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c caught by git; fs/stat.c one got caught by git grep] [fs/xattr.c conflict] Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-08-07Merge tag 'for-6.11-rc2-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - fix double inode unlock for direct IO sync writes (reported by syzbot) - fix root tree id/name map definitions, don't use fixed size buffers for name (reported by -Werror=unterminated-string-initialization) - fix qgroup reserve leaks in bufferd write path - update scrub status structure more often so it can be reported in user space more accurately and let 'resume' not repeat work - in preparation to remove space cache v1 in the future print a warning if it's detected * tag 'for-6.11-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: avoid using fixed char array size for tree names btrfs: fix double inode unlock for direct IO sync writes btrfs: emit a warning about space cache v1 being deprecated btrfs: fix qgroup reserve leaks in cow_file_range btrfs: implement launder_folio for clearing dirty page reserve btrfs: scrub: update last_physical after scrubbing one stripe btrfs: factor out stripe length calculation into a helper
2024-08-02btrfs: avoid using fixed char array size for tree namesQu Wenruo
[BUG] There is a bug report that using the latest trunk GCC 15, btrfs would cause unterminated-string-initialization warning: linux-6.6/fs/btrfs/print-tree.c:29:49: error: initializer-string for array of ‘char’ is too long [-Werror=unterminated-string-initialization] 29 | { BTRFS_BLOCK_GROUP_TREE_OBJECTID, "BLOCK_GROUP_TREE" }, | ^~~~~~~~~~~~~~~~~~ [CAUSE] To print tree names we have an array of root_name_map structure, which uses "char name[16];" to store the name string of a tree. But the following trees have names exactly at 16 chars length: - "BLOCK_GROUP_TREE" - "RAID_STRIPE_TREE" This means we will have no space for the terminating '\0', and can lead to unexpected access when printing the name. [FIX] Instead of "char name[16];" use "const char *" instead. Since the name strings are all read-only data, and are all NULL terminated by default, there is not much need to bother the length at all. Reported-by: Sam James <sam@gentoo.org> Reported-by: Alejandro Colomar <alx@kernel.org> Fixes: edde81f1abf29 ("btrfs: add raid stripe tree pretty printer") Fixes: 9c54e80ddc6bd ("btrfs: add code to support the block group root") CC: stable@vger.kernel.org # 6.1+ Suggested-by: Alejandro Colomar <alx@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Alejandro Colomar <alx@kernel.org> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-02btrfs: fix double inode unlock for direct IO sync writesFilipe Manana
If we do a direct IO sync write, at btrfs_sync_file(), and we need to skip inode logging or we get an error starting a transaction or an error when flushing delalloc, we end up unlocking the inode when we shouldn't under the 'out_release_extents' label, and then unlock it again at btrfs_direct_write(). Fix that by checking if we have to skip inode unlocking under that label. Reported-by: syzbot+7dbbb74af6291b5a5a8b@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/000000000000dfd631061eaeb4bc@google.com/ Fixes: 939b656bc8ab ("btrfs: fix corruption after buffer fault in during direct IO append write") Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-01btrfs: emit a warning about space cache v1 being deprecatedJosef Bacik
We've been wanting to get rid of this for a while, add a message to indicate that this feature is going away and when so we can finally have a date when we're going to remove it. The output looks like this BTRFS warning (device nvme0n1): space cache v1 is being deprecated and will be removed in a future release, please use -o space_cache=v2 Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Neal Gompa <neal@gompa.dev> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-01btrfs: fix qgroup reserve leaks in cow_file_rangeBoris Burkov
In the buffered write path, the dirty page owns the qgroup reserve until it creates an ordered_extent. Therefore, any errors that occur before the ordered_extent is created must free that reservation, or else the space is leaked. The fstest generic/475 exercises various IO error paths, and is able to trigger errors in cow_file_range where we fail to get to allocating the ordered extent. Note that because we *do* clear delalloc, we are likely to remove the inode from the delalloc list, so the inodes/pages to not have invalidate/launder called on them in the commit abort path. This results in failures at the unmount stage of the test that look like: BTRFS: error (device dm-8 state EA) in cleanup_transaction:2018: errno=-5 IO failure BTRFS: error (device dm-8 state EA) in btrfs_replace_file_extents:2416: errno=-5 IO failure BTRFS warning (device dm-8 state EA): qgroup 0/5 has unreleased space, type 0 rsv 28672 ------------[ cut here ]------------ WARNING: CPU: 3 PID: 22588 at fs/btrfs/disk-io.c:4333 close_ctree+0x222/0x4d0 [btrfs] Modules linked in: btrfs blake2b_generic libcrc32c xor zstd_compress raid6_pq CPU: 3 PID: 22588 Comm: umount Kdump: loaded Tainted: G W 6.10.0-rc7-gab56fde445b8 #21 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 RIP: 0010:close_ctree+0x222/0x4d0 [btrfs] RSP: 0018:ffffb4465283be00 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffffa1a1818e1000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffb4465283bbe0 RDI: ffffa1a19374fcb8 RBP: ffffa1a1818e13c0 R08: 0000000100028b16 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000003 R12: ffffa1a18ad7972c R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f9168312b80(0000) GS:ffffa1a4afcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f91683c9140 CR3: 000000010acaa000 CR4: 00000000000006f0 Call Trace: <TASK> ? close_ctree+0x222/0x4d0 [btrfs] ? __warn.cold+0x8e/0xea ? close_ctree+0x222/0x4d0 [btrfs] ? report_bug+0xff/0x140 ? handle_bug+0x3b/0x70 ? exc_invalid_op+0x17/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? close_ctree+0x222/0x4d0 [btrfs] generic_shutdown_super+0x70/0x160 kill_anon_super+0x11/0x40 btrfs_kill_super+0x11/0x20 [btrfs] deactivate_locked_super+0x2e/0xa0 cleanup_mnt+0xb5/0x150 task_work_run+0x57/0x80 syscall_exit_to_user_mode+0x121/0x130 do_syscall_64+0xab/0x1a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f916847a887 ---[ end trace 0000000000000000 ]--- BTRFS error (device dm-8 state EA): qgroup reserved space leaked Cases 2 and 3 in the out_reserve path both pertain to this type of leak and must free the reserved qgroup data. Because it is already an error path, I opted not to handle the possible errors in btrfs_free_qgroup_data. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-01btrfs: implement launder_folio for clearing dirty page reserveBoris Burkov
In the buffered write path, dirty pages can be said to "own" the qgroup reservation until they create an ordered_extent. It is possible for there to be outstanding dirty pages when a transaction is aborted, in which case there is no cancellation path for freeing this reservation and it is leaked. We do already walk the list of outstanding delalloc inodes in btrfs_destroy_delalloc_inodes() and call invalidate_inode_pages2() on them. This does *not* call btrfs_invalidate_folio(), as one might guess, but rather calls launder_folio() and release_folio(). Since this is a reservation associated with dirty pages only, rather than something associated with the private bit (ordered_extent is cancelled separately already in the cleanup transaction path), implementing this release should be done via launder_folio. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-01btrfs: scrub: update last_physical after scrubbing one stripeQu Wenruo
Currently sctx->stat.last_physical only got updated in the following cases: - When the last stripe of a non-RAID56 chunk is scrubbed This implies a pitfall, if the last stripe is at the chunk boundary, and we finished the scrub of the whole chunk, we won't update last_physical at all until the next chunk. - When a P/Q stripe of a RAID56 chunk is scrubbed This leads the following two problems: - sctx->stat.last_physical is not updated for a almost full chunk This is especially bad, affecting scrub resume, as the resume would start from last_physical, causing unnecessary re-scrub. - "btrfs scrub status" will not report any progress for a long time Fix the problem by properly updating @last_physical after each stripe is scrubbed. And since we're here, for the sake of consistency, use spin lock to protect the update of @last_physical, just like all the remaining call sites touching sctx->stat. Reported-by: Michel Palleau <michel.palleau@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CAMFk-+igFTv2E8svg=cQ6o3e6CrR5QwgQ3Ok9EyRaEvvthpqCQ@mail.gmail.com/ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-01btrfs: factor out stripe length calculation into a helperQu Wenruo
Currently there are two locations which need to calculate the real length of a stripe (which can be at the end of a chunk, and the chunk size may not always be 64K aligned). Factor them into a helper as we're going to have a third user soon. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>