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2020-03-23btrfs: hold a ref on the root in record_reloc_root_in_transJosef Bacik
We are recording this root in the transaction, so we need to hold a ref on it until we do that. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: hold a ref on the root in merge_reloc_rootsJosef Bacik
We look up the corresponding root for the reloc root, we need to hold a ref while we're messing with it. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: hold a ref on the root in prepare_to_mergeJosef Bacik
We look up the reloc roots corresponding root, we need to hold a ref on that root. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: hold a ref on the root in build_backref_treeJosef Bacik
This is trickier than the previous conversions. We have backref_node's that need to hold onto their root for their lifetime. Do the read of the root and grab the ref. If at any point we don't use the root we discard it, however if we use it in our backref node we don't free it until we free the backref node. Any time we switch the root's for the backref node we need to drop our ref on the old root and grab the ref on the new root, and if we dupe a node we need to get a ref on the root there 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>
2020-03-23btrfs: hold ref on root in btrfs_ioctl_default_subvolJosef Bacik
We look up an arbitrary fs root here, we need to hold a ref on the root for the duration. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: hold a ref on the root in btrfs_ioctl_get_subvol_infoJosef Bacik
We look up whatever root userspace has given us, we need to hold a ref throughout this operation. Use 'root' only for the on fs root and not as a temporary variable elsewhere. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: hold a ref on the root in btrfs_search_path_in_tree_userJosef Bacik
We can wander into a different root, so grab a ref on the root we look up. Later on we make root = fs_info->tree_root so we need this separate out label to make sure we do the right cleanup only in the case we're looking up a different root. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: hold a ref on the root in btrfs_search_path_in_treeJosef Bacik
We look up an arbitrary fs root, we need to hold a ref on it while we're doing our search. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: hold a ref on the root in search_ioctlJosef Bacik
We lookup a arbitrary fs root, we need to hold a ref on that root. If we're using our own inodes root then grab a ref on that as well to make the cleanup easier. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: hold a ref on the root in create_subvolJosef Bacik
We're creating the new root here, but we should hold the ref until after we've initialized the inode for it. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: hold a ref on the root in fixup_tree_root_locationJosef Bacik
Looking up the inode from an arbitrary tree means we need to hold a ref on that root. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: hold a ref on the root in __btrfs_run_defrag_inodeJosef Bacik
We are looking up an arbitrary inode, we need to hold a ref on the root while we're doing this. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: hold a root ref in btrfs_get_dentryJosef Bacik
Looking up the inode we need to search the root, make sure we hold a reference on that root while we're doing the lookup. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: hold a ref on the root in resolve_indirect_refJosef Bacik
We're looking up a random root, we need to hold a ref on it while we're using it. Reviewed-by: David Sterba <dsterba@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>
2020-03-23btrfs: hold a ref on fs roots while they're in the radix treeJosef Bacik
If the root is sitting in the radix tree, we should probably have a ref for the radix tree. Grab a ref on the root when we insert it, and drop it when it gets deleted. Reviewed-by: Nikolay Borisov <nborisov@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>
2020-03-23btrfs: describe the space reservation system in generalJosef Bacik
Add another comment to cover how the space reservation system works generally. This covers the actual reservation flow, as well as how flushing is handled. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: add a comment describing delalloc space reservationJosef Bacik
delalloc space reservation is tricky because it encompasses both data and metadata. Make it clear what each side does, the general flow of how space is moved throughout the lifetime of a write, and what goes into the calculations. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: add a comment describing block reservesJosef Bacik
This is a giant comment at the top of block-rsv.c describing generally how block reserves work. It is purely about the block reserves themselves, and nothing to do with how the actual reservation system works. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: handle NULL roots in btrfs_put/btrfs_grab_fs_rootJosef Bacik
We want to use this for dropping all roots, and in some error cases we may not have a root, so handle this to make the cleanup code easier. Make btrfs_grab_fs_root the same so we can use it in cases where the root may not exist (like the quota root). Reviewed-by: Nikolay Borisov <nborisov@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>
2020-03-23btrfs: make the fs root init functions staticJosef Bacik
Now that the orphan cleanup stuff doesn't use this directly we can just make them static. Reviewed-by: Nikolay Borisov <nborisov@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>
2020-03-23btrfs: open code btrfs_read_fs_root_no_nameJosef Bacik
All this does is call btrfs_get_fs_root() with check_ref == true. Just use btrfs_get_fs_root() so we don't have a bunch of different helpers that do the same thing. Reviewed-by: Nikolay Borisov <nborisov@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>
2020-03-23btrfs: remove btrfs_read_fs_root, not used anymoreJosef Bacik
All helpers should either be using btrfs_get_fs_root() or btrfs_read_tree_root(). Reviewed-by: Nikolay Borisov <nborisov@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>
2020-03-23btrfs: make relocation use btrfs_read_tree_root()Josef Bacik
Relocation has it's special roots, we don't want to save these in the root cache either, so swap it to use btrfs_read_tree_root(). However the reloc root does need REF_COWS set, so make sure we set it everywhere we use this helper, as it no longer does the REF_COWS setting. Reviewed-by: Nikolay Borisov <nborisov@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>
2020-03-23btrfs: export and use btrfs_read_tree_root for tree-logJosef Bacik
Tree-log uses btrfs_read_fs_root to load its log, but this just calls btrfs_read_tree_root. We don't save the log roots in our root cache, so just export this helper and use it in the logging code. Reviewed-by: Nikolay Borisov <nborisov@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>
2020-03-23btrfs: make btrfs_find_orphan_roots use btrfs_get_fs_rootJosef Bacik
btrfs_find_orphan_roots has this weird thing where it looks up the root in cache to see if it is there before just reading the root. But the read it uses just reads the root, it doesn't do any of the init work, we do that by hand here. But this is unnecessary, all we really want is to see if the root still exists and add it to the dead roots list to be cleaned up, otherwise we delete the orphan item. Fix this by just using btrfs_get_fs_root directly with check_ref set to false so we get the orphan root items. Then we just handle in cache and out of cache roots the same, add them to the dead roots list and carry on. Reviewed-by: Nikolay Borisov <nborisov@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>
2020-03-23btrfs: move fs root init stuff into btrfs_init_fs_rootJosef Bacik
We have a helper for reading fs roots that just reads the fs root off the disk and then sets REF_COWS and init's the inheritable flags. Move this into btrfs_init_fs_root so we can later get rid of this helper and consolidate all of the fs root reading into one helper. Reviewed-by: Nikolay Borisov <nborisov@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>
2020-03-23btrfs: push __setup_root into btrfs_alloc_rootJosef Bacik
There's no reason to not init the root at alloc time, and with later patches it actually causes problems if we error out mounting the fs before the tree_root is init'ed because we expect it to have a valid ref count. Fix this by pushing __setup_root into btrfs_alloc_root. Reviewed-by: Nikolay Borisov <nborisov@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>
2020-03-23btrfs: delete the ordered isize update codeJosef Bacik
Now that we have a safe way to update the isize, remove all of this code as it's no longer needed. Reviewed-by: Filipe Manana <fdmanana@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>
2020-03-23btrfs: replace all uses of btrfs_ordered_update_i_sizeJosef Bacik
Now that we have a safe way to update the i_size, replace all uses of btrfs_ordered_update_i_size with btrfs_inode_safe_disk_i_size_write. Reviewed-by: Filipe Manana <fdmanana@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>
2020-03-23btrfs: use the file extent tree infrastructureJosef Bacik
We want to use this everywhere we modify the file extent items permanently. These include: 1) Inserting new file extents for writes and prealloc extents. 2) Truncating inode items. 3) btrfs_cont_expand(). 4) Insert inline extents. 5) Insert new extents from log replay. 6) Insert a new extent for clone, as it could be past i_size. 7) Hole punching For hole punching in particular it might seem it's not necessary because anybody extending would use btrfs_cont_expand, however there is a corner that still can give us trouble. Start with an empty file and fallocate KEEP_SIZE 1M-2M We now have a 0 length file, and a hole file extent from 0-1M, and a prealloc extent from 1M-2M. Now punch 1M-1.5M Because this is past i_size we have [HOLE EXTENT][ NOTHING ][PREALLOC] [0 1M][1M 1.5M][1.5M 2M] with an i_size of 0. Now if we pwrite 0-1.5M we'll increas our i_size to 1.5M, but our disk_i_size is still 0 until the ordered extent completes. However if we now immediately truncate 2M on the file we'll just call btrfs_cont_expand(inode, 1.5M, 2M), since our old i_size is 1.5M. If we commit the transaction here and crash we'll expose the gap. To fix this we need to clear the file extent mapping for the range that we punched but didn't insert a corresponding file extent for. This will mean the truncate will only get an disk_i_size set to 1M if we crash before the finish ordered io happens. I've written an xfstest to reproduce the problem and validate this fix. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: introduce per-inode file extent treeJosef Bacik
In order to keep track of where we have file extents on disk, and thus where it is safe to adjust the i_size to, we need to have a tree in place to keep track of the contiguous areas we have file extents for. Add helpers to use this tree, as it's not required for NO_HOLES file systems. We will use this by setting DIRTY for areas we know we have file extent item's set, and clearing it when we remove file extent items for truncation. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: use btrfs_ordered_update_i_size in clone_finish_inode_updateJosef Bacik
We were using btrfs_i_size_write(), which unconditionally jacks up inode->disk_i_size. However since clone can operate on ranges we could have pending ordered extents for a range prior to the start of our clone operation and thus increase disk_i_size too far and have a hole with no file extent. Fix this by using the btrfs_ordered_update_i_size helper which will do the right thing in the face of pending ordered extents outside of our clone range. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: update the comment of btrfs_control_ioctl()Su Yue
Btrfsctl was removed in 2012, now the function btrfs_control_ioctl() is only used for devices ioctls. So update the comment. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Su Yue <Damenly_Su@gmx.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23btrfs: relocation: Add introduction of how relocation worksQu Wenruo
Relocation is one of the most complex part of btrfs, while it's also the foundation stone for online resizing, profile converting. For such a complex facility, we should at least have some introduction to it. This patch will add an basic introduction at pretty a high level, explaining: - What relocation does - How relocation is done Only mentioning how data reloc tree and reloc tree are involved in the operation. No details like the backref cache, or the data reloc tree contents. - Which function to refer. More detailed comments will be added for reloc tree creation, data reloc tree creation and backref cache. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23Btrfs: don't iterate mod seq list when putting a tree mod seqFilipe Manana
Each new element added to the mod seq list is always appended to the list, and each one gets a sequence number coming from a counter which gets incremented everytime a new element is added to the list (or a new node is added to the tree mod log rbtree). Therefore the element with the lowest sequence number is always the first element in the list. So just remove the list iteration at btrfs_put_tree_mod_seq() that computes the minimum sequence number in the list and replace it with a check for the first element's sequence number. 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>
2020-03-23btrfs: Add overview of device replaceQu Wenruo
The overview of btrfs dev-replace. It mentions some corner cases caused by the write duplication and scrub based data copy. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ adjust wording ] Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-22Merge tag 'for-5.6-rc6-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "Two fixes. The first is a regression: when dropping some incompat bits the conditions were reversed. The other is a fix for rename whiteout potentially leaving stack memory linked to a list" * tag 'for-5.6-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix removal of raid[56|1c34} incompat flags after removing block group btrfs: fix log context list corruption after rename whiteout error
2020-03-20btrfs: fix removal of raid[56|1c34} incompat flags after removing block groupFilipe Manana
We are incorrectly dropping the raid56 and raid1c34 incompat flags when there are still raid56 and raid1c34 block groups, not when we do not any of those anymore. The logic just got unintentionally broken after adding the support for the raid1c34 modes. Fix this by clear the flags only if we do not have block groups with the respective profiles. Fixes: 9c907446dce3 ("btrfs: drop incompat bit for raid1c34 after last block group is gone") Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-13btrfs: fix log context list corruption after rename whiteout errorFilipe Manana
During a rename whiteout, if btrfs_whiteout_for_rename() returns an error we can end up returning from btrfs_rename() with the log context object still in the root's log context list - this happens if 'sync_log' was set to true before we called btrfs_whiteout_for_rename() and it is dangerous because we end up with a corrupt linked list (root->log_ctxs) as the log context object was allocated on the stack. After btrfs_rename() returns, any task that is running btrfs_sync_log() concurrently can end up crashing because that linked list is traversed by btrfs_sync_log() (through btrfs_remove_all_log_ctxs()). That results in the same issue that commit e6c617102c7e4 ("Btrfs: fix log context list corruption after rename exchange operation") fixed. Fixes: d4682ba03ef618 ("Btrfs: sync log after logging new name") CC: stable@vger.kernel.org # 4.19+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-06Merge tag 'for-5.6-rc4-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fix from David Sterba: "One fixup for DIO when in use with the new checksums, a missed case where the checksum size was still assuming u32" * tag 'for-5.6-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix RAID direct I/O reads with alternate csums
2020-03-03btrfs: fix RAID direct I/O reads with alternate csumsOmar Sandoval
btrfs_lookup_and_bind_dio_csum() does pointer arithmetic which assumes 32-bit checksums. If using a larger checksum, this leads to spurious failures when a direct I/O read crosses a stripe. This is easy to reproduce: # mkfs.btrfs -f --checksum blake2 -d raid0 /dev/vdc /dev/vdd ... # mount /dev/vdc /mnt # cd /mnt # dd if=/dev/urandom of=foo bs=1M count=1 status=none # dd if=foo of=/dev/null bs=1M iflag=direct status=none dd: error reading 'foo': Input/output error # dmesg | tail -1 [ 135.821568] BTRFS warning (device vdc): csum failed root 5 ino 257 off 421888 ... Fix it by using the actual checksum size. Fixes: 1e25a2e3ca0d ("btrfs: don't assume ordered sums to be 4 bytes") CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-23Merge tag 'for-5.6-rc2-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "These are fixes that were found during testing with help of error injection, plus some other stable material. There's a fixup to patch added to rc1 causing locking in wrong context warnings, tests found one more deadlock scenario. The patches are tagged for stable, two of them now in the queue but we'd like all three released at the same time. I'm not happy about fixes to fixes in such a fast succession during rcs, but I hope we found all the fallouts of commit 28553fa992cb ('Btrfs: fix race between shrinking truncate and fiemap')" * tag 'for-5.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Btrfs: fix deadlock during fast fsync when logging prealloc extents beyond eof Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extents btrfs: fix bytes_may_use underflow in prealloc error condtition btrfs: handle logged extent failure properly btrfs: do not check delayed items are empty for single transaction cleanup btrfs: reset fs_root to NULL on error in open_ctree btrfs: destroy qgroup extent records on transaction abort
2020-02-21Btrfs: fix deadlock during fast fsync when logging prealloc extents beyond eofFilipe Manana
While logging the prealloc extents of an inode during a fast fsync we call btrfs_truncate_inode_items(), through btrfs_log_prealloc_extents(), while holding a read lock on a leaf of the inode's root (not the log root, the fs/subvol root), and then that function locks the file range in the inode's iotree. This can lead to a deadlock when: * the fsync is ranged * the file has prealloc extents beyond eof * writeback for a range different from the fsync range starts during the fsync * the size of the file is not sector size aligned Because when finishing an ordered extent we lock first a file range and then try to COW the fs/subvol tree to insert an extent item. The following diagram shows how the deadlock can happen. CPU 1 CPU 2 btrfs_sync_file() --> for range [0, 1MiB) --> inode has a size of 1MiB and has 1 prealloc extent beyond the i_size, starting at offset 4MiB flushes all delalloc for the range [0MiB, 1MiB) and waits for the respective ordered extents to complete --> before task at CPU 1 locks the inode, a write into file range [1MiB, 2MiB + 1KiB) is made --> i_size is updated to 2MiB + 1KiB --> writeback is started for that range, [1MiB, 2MiB + 4KiB) --> end offset rounded up to be sector size aligned btrfs_log_dentry_safe() btrfs_log_inode_parent() btrfs_log_inode() btrfs_log_changed_extents() btrfs_log_prealloc_extents() --> does a search on the inode's root --> holds a read lock on leaf X btrfs_finish_ordered_io() --> locks range [1MiB, 2MiB + 4KiB) --> end offset rounded up to be sector size aligned --> tries to cow leaf X, through insert_reserved_file_extent() --> already locked by the task at CPU 1 btrfs_truncate_inode_items() --> gets an i_size of 2MiB + 1KiB, which is not sector size aligned --> tries to lock file range [2MiB, (u64)-1) --> the start range is rounded down from 2MiB + 1K to 2MiB to be sector size aligned --> but the subrange [2MiB, 2MiB + 4KiB) is already locked by task at CPU 2 which is waiting to get a write lock on leaf X for which we are holding a read lock *** deadlock *** This results in a stack trace like the following, triggered by test case generic/561 from fstests: [ 2779.973608] INFO: task kworker/u8:6:247 blocked for more than 120 seconds. [ 2779.979536] Not tainted 5.6.0-rc2-btrfs-next-53 #1 [ 2779.984503] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 2779.990136] kworker/u8:6 D 0 247 2 0x80004000 [ 2779.990457] Workqueue: btrfs-endio-write btrfs_work_helper [btrfs] [ 2779.990466] Call Trace: [ 2779.990491] ? __schedule+0x384/0xa30 [ 2779.990521] schedule+0x33/0xe0 [ 2779.990616] btrfs_tree_read_lock+0x19e/0x2e0 [btrfs] [ 2779.990632] ? remove_wait_queue+0x60/0x60 [ 2779.990730] btrfs_read_lock_root_node+0x2f/0x40 [btrfs] [ 2779.990782] btrfs_search_slot+0x510/0x1000 [btrfs] [ 2779.990869] btrfs_lookup_file_extent+0x4a/0x70 [btrfs] [ 2779.990944] __btrfs_drop_extents+0x161/0x1060 [btrfs] [ 2779.990987] ? mark_held_locks+0x6d/0xc0 [ 2779.990994] ? __slab_alloc.isra.49+0x99/0x100 [ 2779.991060] ? insert_reserved_file_extent.constprop.19+0x64/0x300 [btrfs] [ 2779.991145] insert_reserved_file_extent.constprop.19+0x97/0x300 [btrfs] [ 2779.991222] ? start_transaction+0xdd/0x5c0 [btrfs] [ 2779.991291] btrfs_finish_ordered_io+0x4f4/0x840 [btrfs] [ 2779.991405] btrfs_work_helper+0xaa/0x720 [btrfs] [ 2779.991432] process_one_work+0x26d/0x6a0 [ 2779.991460] worker_thread+0x4f/0x3e0 [ 2779.991481] ? process_one_work+0x6a0/0x6a0 [ 2779.991489] kthread+0x103/0x140 [ 2779.991499] ? kthread_create_worker_on_cpu+0x70/0x70 [ 2779.991515] ret_from_fork+0x3a/0x50 (...) [ 2780.026211] INFO: task fsstress:17375 blocked for more than 120 seconds. [ 2780.027480] Not tainted 5.6.0-rc2-btrfs-next-53 #1 [ 2780.028482] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 2780.030035] fsstress D 0 17375 17373 0x00004000 [ 2780.030038] Call Trace: [ 2780.030044] ? __schedule+0x384/0xa30 [ 2780.030052] schedule+0x33/0xe0 [ 2780.030075] lock_extent_bits+0x20c/0x320 [btrfs] [ 2780.030094] ? btrfs_truncate_inode_items+0xf4/0x1150 [btrfs] [ 2780.030098] ? rcu_read_lock_sched_held+0x59/0xa0 [ 2780.030102] ? remove_wait_queue+0x60/0x60 [ 2780.030122] btrfs_truncate_inode_items+0x133/0x1150 [btrfs] [ 2780.030151] ? btrfs_set_path_blocking+0xb2/0x160 [btrfs] [ 2780.030165] ? btrfs_search_slot+0x379/0x1000 [btrfs] [ 2780.030195] btrfs_log_changed_extents.isra.8+0x841/0x93e [btrfs] [ 2780.030202] ? do_raw_spin_unlock+0x49/0xc0 [ 2780.030215] ? btrfs_get_num_csums+0x10/0x10 [btrfs] [ 2780.030239] btrfs_log_inode+0xf83/0x1124 [btrfs] [ 2780.030251] ? __mutex_unlock_slowpath+0x45/0x2a0 [ 2780.030275] btrfs_log_inode_parent+0x2a0/0xe40 [btrfs] [ 2780.030282] ? dget_parent+0xa1/0x370 [ 2780.030309] btrfs_log_dentry_safe+0x4a/0x70 [btrfs] [ 2780.030329] btrfs_sync_file+0x3f3/0x490 [btrfs] [ 2780.030339] do_fsync+0x38/0x60 [ 2780.030343] __x64_sys_fdatasync+0x13/0x20 [ 2780.030345] do_syscall_64+0x5c/0x280 [ 2780.030348] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 2780.030356] RIP: 0033:0x7f2d80f6d5f0 [ 2780.030361] Code: Bad RIP value. [ 2780.030362] RSP: 002b:00007ffdba3c8548 EFLAGS: 00000246 ORIG_RAX: 000000000000004b [ 2780.030364] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f2d80f6d5f0 [ 2780.030365] RDX: 00007ffdba3c84b0 RSI: 00007ffdba3c84b0 RDI: 0000000000000003 [ 2780.030367] RBP: 000000000000004a R08: 0000000000000001 R09: 00007ffdba3c855c [ 2780.030368] R10: 0000000000000078 R11: 0000000000000246 R12: 00000000000001f4 [ 2780.030369] R13: 0000000051eb851f R14: 00007ffdba3c85f0 R15: 0000557a49220d90 So fix this by making btrfs_truncate_inode_items() not lock the range in the inode's iotree when the target root is a log root, since it's not needed to lock the range for log roots as the protection from the inode's lock and log_mutex are all that's needed. Fixes: 28553fa992cb28 ("Btrfs: fix race between shrinking truncate and fiemap") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-19Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extentsFilipe Manana
In btrfs_wait_ordered_range() once we find an ordered extent that has finished with an error we exit the loop and don't wait for any other ordered extents that might be still in progress. All the users of btrfs_wait_ordered_range() expect that there are no more ordered extents in progress after that function returns. So past fixes such like the ones from the two following commits: ff612ba7849964 ("btrfs: fix panic during relocation after ENOSPC before writeback happens") 28aeeac1dd3080 ("Btrfs: fix panic when starting bg cache writeout after IO error") don't work when there are multiple ordered extents in the range. Fix that by making btrfs_wait_ordered_range() wait for all ordered extents even after it finds one that had an error. Link: https://github.com/kdave/btrfs-progs/issues/228#issuecomment-569777554 CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-19btrfs: fix bytes_may_use underflow in prealloc error condtitionJosef Bacik
I hit the following warning while running my error injection stress testing: WARNING: CPU: 3 PID: 1453 at fs/btrfs/space-info.h:108 btrfs_free_reserved_data_space_noquota+0xfd/0x160 [btrfs] RIP: 0010:btrfs_free_reserved_data_space_noquota+0xfd/0x160 [btrfs] Call Trace: btrfs_free_reserved_data_space+0x4f/0x70 [btrfs] __btrfs_prealloc_file_range+0x378/0x470 [btrfs] elfcorehdr_read+0x40/0x40 ? elfcorehdr_read+0x40/0x40 ? btrfs_commit_transaction+0xca/0xa50 [btrfs] ? dput+0xb4/0x2a0 ? btrfs_log_dentry_safe+0x55/0x70 [btrfs] ? btrfs_sync_file+0x30e/0x420 [btrfs] ? do_fsync+0x38/0x70 ? __x64_sys_fdatasync+0x13/0x20 ? do_syscall_64+0x5b/0x1b0 ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 This happens if we fail to insert our reserved file extent. At this point we've already converted our reservation from ->bytes_may_use to ->bytes_reserved. However once we break we will attempt to free everything from [cur_offset, end] from ->bytes_may_use, but our extent reservation will overlap part of this. Fix this problem by adding ins.offset (our extent allocation size) to cur_offset so we remove the actual remaining part from ->bytes_may_use. I validated this fix using my inject-error.py script python inject-error.py -o should_fail_bio -t cache_save_setup -t \ __btrfs_prealloc_file_range \ -t insert_reserved_file_extent.constprop.0 \ -r "-5" ./run-fsstress.sh where run-fsstress.sh simply mounts and runs fsstress on a disk. CC: stable@vger.kernel.org # 4.4+ 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>
2020-02-19btrfs: handle logged extent failure properlyJosef Bacik
If we're allocating a logged extent we attempt to insert an extent record for the file extent directly. We increase space_info->bytes_reserved, because the extent entry addition will call btrfs_update_block_group(), which will convert the ->bytes_reserved to ->bytes_used. However if we fail at any point while inserting the extent entry we will bail and leave space on ->bytes_reserved, which will trigger a WARN_ON() on umount. Fix this by pinning the space if we fail to insert, which is what happens in every other failure case that involves adding the extent entry. CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> 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>
2020-02-19btrfs: do not check delayed items are empty for single transaction cleanupJosef Bacik
btrfs_assert_delayed_root_empty() will check if the delayed root is completely empty, but this is a filesystem-wide check. On cleanup we may have allowed other transactions to begin, for whatever reason, and thus the delayed root is not empty. So remove this check from cleanup_one_transation(). This however can stay in btrfs_cleanup_transaction(), because it checks only after all of the transactions have been properly cleaned up, and thus is valid. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> 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>
2020-02-19btrfs: reset fs_root to NULL on error in open_ctreeJosef Bacik
While running my error injection script I hit a panic when we tried to clean up the fs_root when freeing the fs_root. This is because fs_info->fs_root == PTR_ERR(-EIO), which isn't great. Fix this by setting fs_info->fs_root = NULL; if we fail to read the root. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> 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>
2020-02-19btrfs: destroy qgroup extent records on transaction abortJeff Mahoney
We clean up the delayed references when we abort a transaction but we leave the pending qgroup extent records behind, leaking memory. This patch destroys the extent records when we destroy the delayed refs and makes sure ensure they're gone before releasing the transaction. Fixes: 3368d001ba5d ("btrfs: qgroup: Record possible quota-related extent for qgroup.") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jeff Mahoney <jeffm@suse.com> [ Rebased to latest upstream, remove to_qgroup() helper, use rbtree_postorder_for_each_entry_safe() wrapper ] Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-17Merge tag 'for-5.6-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fix from David Sterba: "This is the fix for sleeping in a locked section bug reported by Dave Jones, caused by a patch dependence in development and pulled branches. I picked the existing patch over the fixup that Filipe sent, as it's a bit more generic fix. I've verified it with a specific test case, some rsync stress and one round of fstests" * tag 'for-5.6-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: don't set path->leave_spinning for truncate