btrfs: add helper to get fs_info from struct inode pointer Add a convenience helper to get a fs_info from a VFS inode pointer instead of open coding the chain or using btrfs_sb() that in some cases does one more pointer hop. This is implemented as a macro (still with type checking) so we don't need full definitions of struct btrfs_inode, btrfs_root or btrfs_fs_info. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: preallocate temporary extent buffer for inode logging when needed When logging an inode and we require to copy items from subvolume leaves to the log tree, we clone each subvolume leaf and than use that clone to copy items to the log tree. This is required to avoid possible deadlocks as stated in commit 796787c978ef ("btrfs: do not modify log tree while holding a leaf from fs tree locked"). The cloning requires allocating an extent buffer (struct extent_buffer) and then allocating pages (folios) to attach to the extent buffer. This may be slow in case we are under memory pressure, and since we are doing the cloning while holding a read lock on a subvolume leaf, it means we can be blocking other operations on that leaf for significant periods of time, which can increase latency on operations like creating other files, renaming files, etc. Similarly because we're under a log transaction, we may also cause extra delay on other tasks doing an fsync, because syncing the log requires waiting for tasks that joined a log transaction to exit the transaction. So to improve this, for any inode logging operation that needs to copy items from a subvolume leaf ("full sync" or "copy everything" bit set in the inode), preallocate a dummy extent buffer before locking any extent buffer from the subvolume tree, and even before joining a log transaction, add it to the log context and then use it when we need to copy items from a subvolume leaf to the log tree. This avoids making other operations get extra latency when waiting to lock a subvolume leaf that is used during inode logging and we are under heavy memory pressure. The following test script with bonnie++ was used to test this: $ cat test.sh #!/bin/bash DEV=/dev/sdh MNT=/mnt/sdh MOUNT_OPTIONS="-o ssd" MEMTOTAL_BYTES=`free -b | grep Mem: | awk '{ print $2 }'` NR_DIRECTORIES=20 NR_FILES=20480 DATASET_SIZE=$((MEMTOTAL_BYTES * 2 / 1048576)) DIRECTORY_SIZE=$((MEMTOTAL_BYTES * 2 / NR_FILES)) NR_FILES=$((NR_FILES / 1024)) echo "performance" | \ tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor umount $DEV &> /dev/null mkfs.btrfs -f $MKFS_OPTIONS $DEV mount $MOUNT_OPTIONS $DEV $MNT bonnie++ -u root -d $MNT \ -n $NR_FILES:$DIRECTORY_SIZE:$DIRECTORY_SIZE:$NR_DIRECTORIES \ -r 0 -s $DATASET_SIZE -b umount $MNT The results of this test on a 8G VM running a non-debug kernel (Debian's default kernel config), were the following. Before this change: Version 2.00a ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Name:Size etc /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP debian0 7501M 376k 99 1.4g 96 117m 14 1510k 99 2.5g 95 +++++ +++ Latency 35068us 24976us 2944ms 30725us 71770us 26152us Version 2.00a ------Sequential Create------ --------Random Create-------- debian0 -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files:max:min /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 20:384100:384100/20 20480 32 20480 58 20480 48 20480 39 20480 56 20480 61 Latency 411ms 11914us 119ms 617ms 10296us 110ms After this change: Version 2.00a ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Name:Size etc /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP debian0 7501M 375k 99 1.4g 97 117m 14 1546k 99 2.3g 98 +++++ +++ Latency 35975us 20945us 2144ms 10297us 2217us 6004us Version 2.00a ------Sequential Create------ --------Random Create-------- debian0 -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files:max:min /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 20:384100:384100/20 20480 35 20480 58 20480 48 20480 40 20480 57 20480 59 Latency 320ms 11237us 77779us 518ms 6470us 86389us 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>
btrfs: remove unused included headers With help of neovim, LSP and clangd we can identify header files that are not actually needed to be included in the .c files. This is focused only on removal (with minor fixups), further cleanups are possible but will require doing the header files properly with forward declarations, minimized includes and include-what-you-use care. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: replace i_blocksize by fs_info::sectorsize The block size calculated by i_blocksize from inode is the same as what we have in fs_info, initalized in inode_init_always(). Unify that to use the fs_info value everywhere. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: remove the pg_offset parameter from btrfs_get_extent() The parameter @pg_offset of btrfs_get_extent() is only utilized for inlined extent, and we already have an ASSERT() and tree-checker, to make sure we can only get inline extent at file offset 0. Any invalid inline extent with non-zero file offset would be rejected by tree-checker in the first place. Thus the @pg_offset parameter is not really necessary, just remove it. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: migrate subpage code to folio interfaces Although subpage itself is conflicting with higher folio, since subpage (sectorsize < PAGE_SIZE and nodesize < PAGE_SIZE) means we will never need higher order folio, there is a hidden pitfall: - btrfs_page_*() helpers Those helpers are an abstraction to handle both subpage and non-subpage cases, which means we're going to pass pages pointers to those helpers. And since those helpers are shared between data and metadata paths, it's unavoidable to let them to handle folios, including higher order folios). Meanwhile for true subpage case, we should only have a single page backed folios anyway, thus add a new ASSERT() for btrfs_subpage_assert() to ensure that. Also since those helpers are shared between both data and metadata, add some extra ASSERT()s for data path to make sure we only get single page backed folio for now. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: use the flags of an extent map to identify the compression type Currently, in struct extent_map, we use an unsigned int (32 bits) to identify the compression type of an extent and an unsigned long (64 bits on a 64 bits platform, 32 bits otherwise) for flags. We are only using 6 different flags, so an unsigned long is excessive and we can use flags to identify the compression type instead of using a dedicated 32 bits field. We can easily have tens or hundreds of thousands (or more) of extent maps on busy and large filesystems, specially with compression enabled or many or large files with tons of small extents. So it's convenient to have the extent_map structure as small as possible in order to use less memory. So remove the compression type field from struct extent_map, use flags to identify the compression type and shorten the flags field from an unsigned long to a u32. This saves 8 bytes (on 64 bits platforms) and reduces the size of the structure from 136 bytes down to 128 bytes, using now only two cache lines, and increases the number of extent maps we can have per 4K page from 30 to 32. By using a u32 for the flags instead of an unsigned long, we no longer use test_bit(), set_bit() and clear_bit(), but that level of atomicity is not needed as most flags are never cleared once set (before adding an extent map to the tree), and the ones that can be cleared or set after an extent map is added to the tree, are always performed while holding the write lock on the extent map tree, while the reader holds a lock on the tree or tests for a flag that never changes once the extent map is in the tree (such as compression flags). Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: migrate to use folio private instead of page private As a cleanup and preparation for future folio migration, this patch would replace all page->private to folio version. This includes: - PagePrivate() -> folio_test_private() - page->private -> folio_get_private() - attach_page_private() -> folio_attach_private() - detach_page_private() -> folio_detach_private() Since we're here, also remove the forced cast on page->private, since it's (void *) already, we don't really need to do the cast. For now even if we missed some call sites, it won't cause any problem yet, as we're only using order 0 folio (single page), thus all those folio/page flags should be synced. But for the future conversion to utilize higher order folio, the page <-> folio flag sync is no longer guaranteed, thus we have to migrate to utilize folio flags. Reviewed-by: Josef Bacik <josef@toxicpanda.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>
Merge tag 'for-6.7-rc5-tag' of git://git./linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "Some fixes to quota accounting code, mostly around error handling and correctness: - free reserves on various error paths, after IO errors or transaction abort - don't clear reserved range at the folio release time, it'll be properly cleared after final write - fix integer overflow due to int used when passing around size of freed reservations - fix a regression in squota accounting that missed some cases with delayed refs" * tag 'for-6.7-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: ensure releasing squota reserve on head refs btrfs: don't clear qgroup reserved bit in release_folio btrfs: free qgroup pertrans reserve on transaction abort btrfs: fix qgroup_free_reserved_data int overflow btrfs: free qgroup reserve when ORDERED_IOERR is set
btrfs: fix qgroup_free_reserved_data int overflow The reserved data counter and input parameter is a u64, but we inadvertently accumulate it in an int. Overflowing that int results in freeing the wrong amount of data and breaking reserve accounting. Unfortunately, this overflow rot spreads from there, as the qgroup release/free functions rely on returning an int to take advantage of negative values for error codes. Therefore, the full fix is to return the "released" or "freed" amount by a u64 argument and to return 0 or negative error code via the return value. Most of the call sites simply ignore the return value, though some of them handle the error and count the returned bytes. Change all of them accordingly. CC: stable@vger.kernel.org # 6.1+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Merge tag 'for-6.7-tag' of git://git./linux/kernel/git/kdave/linux Pull btrfs updates from David Sterba: "New features: - raid-stripe-tree New tree for logical file extent mapping where the physical mapping may not match on multiple devices. This is now used in zoned mode to implement RAID0/RAID1* profiles, but can be used in non-zoned mode as well. The support for RAID56 is in development and will eventually fix the problems with the current implementation. This is a backward incompatible feature and has to be enabled at mkfs time. - simple quota accounting (squota) A simplified mode of qgroup that accounts all space on the initial extent owners (a subvolume), the snapshots are then cheap to create and delete. The deletion of snapshots in fully accounting qgroups is a known CPU/IO performance bottleneck. The squota is not suitable for the general use case but works well for containers where the original subvolume exists for the whole time. This is a backward incompatible feature as it needs extending some structures, but can be enabled on an existing filesystem. - temporary filesystem fsid (temp_fsid) The fsid identifies a filesystem and is hard coded in the structures, which disallows mounting the same fsid found on different devices. For a single device filesystem this is not strictly necessary, a new temporary fsid can be generated on mount e.g. after a device is cloned. This will be used by Steam Deck for root partition A/B testing, or can be used for VM root images. Other user visible changes: - filesystems with partially finished metadata_uuid conversion cannot be mounted anymore and the uuid fixup has to be done by btrfs-progs (btrfstune). Performance improvements: - reduce reservations for checksum deletions (with enabled free space tree by factor of 4), on a sample workload on file with many extents the deletion time decreased by 12% - make extent state merges more efficient during insertions, reduce rb-tree iterations (run time of critical functions reduced by 5%) Core changes: - the integrity check functionality has been removed, this was a debugging feature and removal does not affect other integrity checks like checksums or tree-checker - space reservation changes: - more efficient delayed ref reservations, this avoids building up too much work or overusing or exhausting the global block reserve in some situations - move delayed refs reservation to the transaction start time, this prevents some ENOSPC corner cases related to exhaustion of global reserve - improvements in reducing excessive reservations for block group items - adjust overcommit logic in near full situations, account for one more chunk to eventually allocate metadata chunk, this is mostly relevant for small filesystems (<10GiB) - single device filesystems are scanned but not registered (except seed devices), this allows temp_fsid to work - qgroup iterations do not need GFP_ATOMIC allocations anymore - cleanups, refactoring, reduced data structure size, function parameter simplifications, error handling fixes" * tag 'for-6.7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (156 commits) btrfs: open code timespec64 in struct btrfs_inode btrfs: remove redundant log root tree index assignment during log sync btrfs: remove redundant initialization of variable dirty in btrfs_update_time() btrfs: sysfs: show temp_fsid feature btrfs: disable the device add feature for temp-fsid btrfs: disable the seed feature for temp-fsid btrfs: update comment for temp-fsid, fsid, and metadata_uuid btrfs: remove pointless empty log context list check when syncing log btrfs: update comment for struct btrfs_inode::lock btrfs: remove pointless barrier from btrfs_sync_file() btrfs: add and use helpers for reading and writing last_trans_committed btrfs: add and use helpers for reading and writing fs_info->generation btrfs: add and use helpers for reading and writing log_transid btrfs: add and use helpers for reading and writing last_log_commit btrfs: support cloned-device mount capability btrfs: add helper function find_fsid_by_disk btrfs: stop reserving excessive space for block group item insertions btrfs: stop reserving excessive space for block group item updates btrfs: reorder btrfs_inode to fill gaps btrfs: open code btrfs_ordered_inode_tree in btrfs_inode ...
btrfs: convert to new timestamp accessors Convert to using the new inode timestamp accessor functions. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20231004185347.80880-21-jlayton@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
btrfs: remove pointless barrier from btrfs_sync_file() The memory barrier (smp_mb()) at btrfs_sync_file() is completely redundant now that fs_info->last_trans_committed is read using READ_ONCE(), with the helper btrfs_get_last_trans_committed(), and written using WRITE_ONCE() with the helper btrfs_set_last_trans_committed(). This barrier was introduced in 2011, by commit a4abeea41adf ("Btrfs: kill trans_mutex"), but even back then it was not correct since the writer side (in btrfs_commit_transaction()), did not issue a pairing memory barrier after it updated fs_info->last_trans_committed. So remove this barrier. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: add and use helpers for reading and writing last_trans_committed Currently the last_trans_committed field of struct btrfs_fs_info is modified and read without any locking or other protection. For example early in the fsync path, skip_inode_logging() is called which reads fs_info->last_trans_committed, but at the same time we can have a transaction commit completing and updating that field. In the case of an fsync this is harmless and any data race should be rare and at most cause an unnecessary logging of an inode. To avoid data race warnings from tools like KCSAN and other issues such as load and store tearing (amongst others, see [1]), create helpers to access the last_trans_committed field of struct btrfs_fs_info using READ_ONCE() and WRITE_ONCE(), and use these helpers everywhere. [1] https://lwn.net/Articles/793253/ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: add and use helpers for reading and writing fs_info->generation Currently the generation field of struct btrfs_fs_info is always modified while holding fs_info->trans_lock locked. Most readers will access this field without taking that lock but while holding a transaction handle, which is safe to do due to the transaction life cycle. However there are other readers that are neither holding the lock nor holding a transaction handle open: 1) When reading an inode from disk, at btrfs_read_locked_inode(); 2) When reading the generation to expose it to sysfs, at btrfs_generation_show(); 3) Early in the fsync path, at skip_inode_logging(); 4) When creating a hole at btrfs_cont_expand(), during write paths, truncate and reflinking; 5) In the fs_info ioctl (btrfs_ioctl_fs_info()); 6) While mounting the filesystem, in the open_ctree() path. In these cases it's safe to directly read fs_info->generation as no one can concurrently start a transaction and update fs_info->generation. In case of the fsync path, races here should be harmless, and in the worst case they may cause a fsync to log an inode when it's not really needed, so nothing bad from a functional perspective. In the other cases it's not so clear if functional problems may arise, though in case 1 rare things like a load/store tearing [1] may cause the BTRFS_INODE_NEEDS_FULL_SYNC flag not being set on an inode and therefore result in incorrect logging later on in case a fsync call is made. To avoid data race warnings from tools like KCSAN and other issues such as load and store tearing (amongst others, see [1]), create helpers to access the generation field of struct btrfs_fs_info using READ_ONCE() and WRITE_ONCE(), and use these helpers where needed. [1] https://lwn.net/Articles/793253/ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: remove redundant root argument from btrfs_update_inode() The root argument for btrfs_update_inode() always matches the root of the given inode, so remove the root argument and get it from the inode argument. 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>
btrfs: track owning root in btrfs_ref While data extents require us to store additional inline refs to track the original owner on free, this information is available implicitly for metadata. It is found in the owner field of the header of the tree block. Even if other trees refer to this block and the original ref goes away, we will not rewrite that header field, so it will reliably give the original owner. In addition, there is a relocation case where a new data extent needs to have an owning root separate from the referring root wired through delayed refs. To use it for recording simple quota deltas, we need to wire this root id through from when we create the delayed ref until we fully process it. Store it in the generic btrfs_ref struct of the delayed ref. Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: abort transaction on generation mismatch when marking eb as dirty When marking an extent buffer as dirty, at btrfs_mark_buffer_dirty(), we check if its generation matches the running transaction and if not we just print a warning. Such mismatch is an indicator that something really went wrong and only printing a warning message (and stack trace) is not enough to prevent a corruption. Allowing a transaction to commit with such an extent buffer will trigger an error if we ever try to read it from disk due to a generation mismatch with its parent generation. So abort the current transaction with -EUCLEAN if we notice a generation mismatch. For this we need to pass a transaction handle to btrfs_mark_buffer_dirty() which is always available except in test code, in which case we can pass NULL since it operates on dummy extent buffers and all test roots have a single node/leaf (root node at level 0). Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
btrfs: include linux/iomap.h in file.c We use the iomap code in file.c, include it so we have our dependencies. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Merge tag 'v6.6-rc3.vfs.ctime.revert' of git://git./linux/kernel/git/vfs/vfs Pull finegrained timestamp reverts from Christian Brauner: "Earlier this week we sent a few minor fixes for the multi-grained timestamp work in [1]. While we were polishing those up after Linus realized that there might be a nicer way to fix them we received a regression report in [2] that fine grained timestamps break gnulib tests and thus possibly other tools. The kernel will elide fine-grain timestamp updates when no one is actively querying for them to avoid performance impacts. So a sequence like write(f1) stat(f2) write(f2) stat(f2) write(f1) stat(f1) may result in timestamp f1 to be older than the final f2 timestamp even though f1 was last written too but the second write didn't update the timestamp. Such plotholes can lead to subtle bugs when programs compare timestamps. For example, the nap() function in [2] will estimate that it needs to wait one ns on a fine-grain timestamp enabled filesytem between subsequent calls to observe a timestamp change. But in general we don't update timestamps with more than one jiffie if we think that no one is actively querying for fine-grain timestamps to avoid performance impacts. While discussing various fixes the decision was to go back to the drawing board and ultimately to explore a solution that involves only exposing such fine-grained timestamps to nfs internally and never to userspace. As there are multiple solutions discussed the honest thing to do here is not to fix this up or disable it but to cleanly revert. The general infrastructure will probably come back but there is no reason to keep this code in mainline. The general changes to timestamp handling are valid and a good cleanup that will stay. The revert is fully bisectable" Link: https://lore.kernel.org/all/20230918-hirte-neuzugang-4c2324e7bae3@brauner [1] Link: https://lore.kernel.org/all/bf0524debb976627693e12ad23690094e4514303.camel@linuxfromscratch.org [2] * tag 'v6.6-rc3.vfs.ctime.revert' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: Revert "fs: add infrastructure for multigrain timestamps" Revert "btrfs: convert to multigrain timestamps" Revert "ext4: switch to multigrain timestamps" Revert "xfs: switch to multigrain timestamps" Revert "tmpfs: add support for multigrain timestamps"