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path: root/fs/btrfs/volumes.h
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2023-06-19btrfs: add and fix comments in btrfs_fs_devicesAnand Jain
Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19btrfs: add comment about metadata_uuid in btrfs_fs_devicesAnand Jain
Add comment about metadata_uuid in btrfs_fs_devices. No functional change. Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19btrfs: reduce struct btrfs_fs_devices size by moving fsid_changeAnand Jain
Pack bool fsid_change and bool seeding with other bool declarations in the struct btrfs_fs_devices, approximately 6 bytes is saved, depending on the config. before: 512 bytes after: 496 bytes Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-19btrfs: make btrfs_free_device() staticFilipe Manana
The function btrfs_free_device() is never used outside of volumes.c, so make it static and remove its prototype declaration at volumes.h. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-06-12block: replace fmode_t with a block-specific type for block open flagsChristoph Hellwig
The only overlap between the block open flags mapped into the fmode_t and other uses of fmode_t are FMODE_READ and FMODE_WRITE. Define a new blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and ->ioctl and stop abusing fmode_t. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd] Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-12block: use the holder as indication for exclusive opensChristoph Hellwig
The current interface for exclusive opens is rather confusing as it requires both the FMODE_EXCL flag and a holder. Remove the need to pass FMODE_EXCL and just key off the exclusive open off a non-NULL holder. For blkdev_put this requires adding the holder argument, which provides better debug checking that only the holder actually releases the hold, but at the same time allows removing the now superfluous mode argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Christian Brauner <brauner@kernel.org> Acked-by: David Sterba <dsterba@suse.com> [btrfs] Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd] Link: https://lore.kernel.org/r/20230608110258.189493-16-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-12btrfs: don't pass a holder for non-exclusive blkdev_get_by_pathChristoph Hellwig
Passing a holder to blkdev_get_by_path when FMODE_EXCL isn't set doesn't make sense, so pass NULL instead and remove the holder argument from the call chains the only end up in non-FMODE_EXCL blkdev_get_by_path calls. Exclusive mode for device scanning is not used since commit 50d281fc434c ("btrfs: scan device in non-exclusive mode")". Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Christian Brauner <brauner@kernel.org> Acked-by: David Sterba <dsterba@suse.com> Link: https://lore.kernel.org/r/20230608110258.189493-15-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-17btrfs: introduce a new helper to submit write bio for repairQu Wenruo
Both scrub and read-repair are utilizing a special repair writes that: - Only writes back to a single device Even for read-repair on RAID56, we only update the corrupted data stripe itself, not triggering the full RMW path. - Requires a valid @mirror_num For RAID56 case, only @mirror_num == 1 is valid. For non-RAID56 cases, we need @mirror_num to locate our stripe. - No data csum generation needed These two call sites still have some differences though: - Read-repair goes plain bio It doesn't need a full btrfs_bio, and goes submit_bio_wait(). - New scrub repair would go btrfs_bio To simplify both read and write path. So here this patch would: - Introduce a common helper, btrfs_map_repair_block() Due to the single device nature, we can use an on-stack btrfs_io_stripe to pass device and its physical bytenr. - Introduce a new interface, btrfs_submit_repair_bio(), for later scrub code This is for the incoming scrub code. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-17btrfs: replace btrfs_io_context::raid_map with a fixed u64 valueQu Wenruo
In btrfs_io_context structure, we have a pointer raid_map, which indicates the logical bytenr for each stripe. But considering we always call sort_parity_stripes(), the result raid_map[] is always sorted, thus raid_map[0] is always the logical bytenr of the full stripe. So why we waste the space and time (for sorting) for raid_map? This patch will replace btrfs_io_context::raid_map with a single u64 number, full_stripe_start, by: - Replace btrfs_io_context::raid_map with full_stripe_start - Replace call sites using raid_map[0] to use full_stripe_start - Replace call sites using raid_map[i] to compare with nr_data_stripes. The benefits are: - Less memory wasted on raid_map It's sizeof(u64) * num_stripes vs sizeof(u64). It'll always save at least one u64, and the benefit grows larger with num_stripes. - No more weird alloc_btrfs_io_context() behavior As there is only one fixed size + one variable length array. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-17btrfs: use an efficient way to represent source of duplicated stripesQu Wenruo
For btrfs dev-replace, we have to duplicate writes to the source device into the target device. For non-RAID56, all writes into the same mapped ranges are sharing the same content, thus they don't really need to bother anything. (E.g. in btrfs_submit_bio() for non-RAID56 range we just submit the same write to all involved devices). But for RAID56, all stripes contain different content, thus we must have a clear mapping of which stripe is duplicated from which original stripe. Currently we use a complex way using tgtdev_map[] array, e.g: num_tgtdevs = 1 tgtdev_map[0] = 0 <- Means stripes[0] is not involved in replace. tgtdev_map[1] = 3 <- Means stripes[1] is involved in replace, and it's duplicated to stripes[3]. tgtdev_map[2] = 0 <- Means stripes[2] is not involved in replace. But this is wasting some space, and ignores one important thing for dev-replace, there is at most one running replace. Thus we can change it to a fixed array to represent the mapping: replace_nr_stripes = 1 replace_stripe_src = 1 <- Means stripes[1] is involved in replace. thus the extra stripe is a copy of stripes[1] By this we can save some space for bioc on RAID56 chunks with many devices. And we get rid of one variable sized array from bioc. Thus the patch involves the following changes: - Replace @num_tgtdevs and @tgtdev_map[] with @replace_nr_stripes and @replace_stripe_src. @num_tgtdevs is just renamed to @replace_nr_stripes. While the mapping is completely changed. - Add extra ASSERT()s for RAID56 code - Only add two more extra stripes for dev-replace cases. As we have an upper limit on how many dev-replace stripes we can have. - Unify the behavior of handle_ops_on_dev_replace() Previously handle_ops_on_dev_replace() go two different paths for WRITE and GET_READ_MIRRORS. Now unify them by always going the WRITE path first (with at most 2 replace stripes), then if we're doing GET_READ_MIRRORS and we have 2 extra stripes, just drop one stripe. - Remove the @real_stripes argument from alloc_btrfs_io_context() As we don't need the old variable length array any more. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-17btrfs: reduce type width of btrfs_io_contextsQu Wenruo
That structure is our ultimate object for all __btrfs_map_block() related functions. We have some hard to understand members, like tgtdev_map, but without any comments. This patch will improve the situation: - Add extra comments for num_stripes, mirror_num, num_tgtdevs and tgtdev_map[] Especially for the last two members, add a dedicated (thus very long) comments for them, with example to explain it. - Shrink those int members to u16. In fact our on-disk format is only using u16 for num_stripes, thus no need to use int at all. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-17btrfs: replace map_lookup->stripe_len by BTRFS_STRIPE_LENQu Wenruo
Currently btrfs doesn't support stripe lengths other than 64KiB. This is already set in the tree-checker. There is really no meaning to record that fixed value in map_lookup for now, and can all be replaced with BTRFS_STRIPE_LEN. Furthermore we can use the fix stripe length to do the following optimization: - Use BTRFS_STRIPE_LEN_SHIFT to replace some 64bit division Now we only need to do a right shift. And the value of BTRFS_STRIPE_LEN itself is already too large for bit shift, thus if we accidentally use BTRFS_STRIPE_LEN to do bit shift, a compiler warning would be triggered. Thus this bit shift optimization would be safe. - Use BTRFS_STRIPE_LEN_MASK to calculate the offset inside a stripe Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: remove struct btrfs_io_geometryChristoph Hellwig
Now that btrfs_get_io_geometry has a single caller, we can massage it into a form that is more suitable for that caller and remove the marshalling into and out of struct btrfs_io_geometry. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Sterba <dsterba@suse.com>
2022-12-05btrfs: split the bio submission path into a separate fileChristoph Hellwig
The code used by btrfs_submit_bio only interacts with the rest of volumes.c through __btrfs_map_block (which itself is a more generic version of two exported helpers) and does not really have anything to do with volumes.c. Create a new bio.c file and a bio.h header going along with it for the btrfs_bio-based storage layer, which will grow even more going forward. Also update the file with my copyright notice given that a large part of the moved code was written or rewritten by me. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-12-05btrfs: move struct btrfs_tree_parent_check out of disk-io.hChristoph Hellwig
Move struct btrfs_tree_parent_check out of disk-io.h so that volumes.h an various .c files don't have to include disk-io.h just for it. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> [ use tree-checker.h for the structure ] Signed-off-by: David Sterba <dsterba@suse.com>
2022-12-05btrfs: use btrfs_dev_name() helper to handle missing devices betterQu Wenruo
[BUG] If dev-replace failed to re-construct its data/metadata, the kernel message would be incorrect for the missing device: BTRFS info (device dm-1): dev_replace from <missing disk> (devid 2) to /dev/mapper/test-scratch2 started BTRFS error (device dm-1): failed to rebuild valid logical 38862848 for dev (efault) Note the above "dev (efault)" of the second line. While the first line is properly reporting "<missing disk>". [CAUSE] Although dev-replace is using btrfs_dev_name(), the heavy lifting work is still done by scrub (scrub is reused by both dev-replace and regular scrub). Unfortunately scrub code never uses btrfs_dev_name() helper, as it's only declared locally inside dev-replace.c. [FIX] Fix the output by: - Move the btrfs_dev_name() helper to volumes.h - Use btrfs_dev_name() to replace open-coded rcu_str_deref() calls Only zoned code is not touched, as I'm not familiar with degraded zoned code. - Constify return value and parameter Now the output looks pretty sane: BTRFS info (device dm-1): dev_replace from <missing disk> (devid 2) to /dev/mapper/test-scratch2 started BTRFS error (device dm-1): failed to rebuild valid logical 38862848 for dev <missing disk> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-12-05btrfs: move tree block parentness check into validate_extent_buffer()Qu Wenruo
[BACKGROUND] Although both btrfs metadata and data has their read time verification done at endio time (btrfs_validate_metadata_buffer() and btrfs_verify_data_csum()), metadata has extra verification, mostly parentness check including first key/transid/owner_root/level, done at read_tree_block() and btrfs_read_extent_buffer(). On the other hand, all the data verification is done at endio context. [ENHANCEMENT] This patch will make a new union in btrfs_bio, taking the space of the old data checksums, thus it will not increase the memory usage. With that extra btrfs_tree_parent_check inside btrfs_bio, we can just pass the check parameter into read_extent_buffer_pages(), and before submitting the bio, we can copy the check structure into btrfs_bio. And finally at endio time, we can grab btrfs_bio::parent_check and pass it to validate_extent_buffer(), to move the remaining checks into it. This brings the following benefits: - Much simpler btrfs_read_extent_buffer() Now it only needs to iterate through all mirrors. - Simpler read-time transid check Previously we go verify_parent_transid() after reading out the extent buffer. Now the transid check is done inside the endio function, no other code can modify the content. Thus no need to use the extent lock anymore. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-12-05btrfs: move device->name RCU allocation and assign to btrfs_alloc_device()Anand Jain
There is a repeating code section in the parent function after calling btrfs_alloc_device(), as below: name = rcu_string_strdup(path, GFP_...); if (!name) { btrfs_free_device(device); return ERR_PTR(-ENOMEM); } rcu_assign_pointer(device->name, name); Except in add_missing_dev() for obvious reasons. This patch consolidates that repeating code into the btrfs_alloc_device() itself so that the parent function doesn't have to duplicate code. This consolidation also helps to review issues regarding RCU lock violation with device->name. Parent function device_list_add() and add_missing_dev() use GFP_NOFS for the allocation, whereas the rest of the parent functions use GFP_KERNEL, so bring the NOFS allocation context using memalloc_nofs_save() in the function device_list_add() and add_missing_dev() is already doing it. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-12-05btrfs: move btrfs_chunk_item_size out of ctree.hJosef Bacik
This is used by the volumes code and the tree checker code. We want to maintain inline however, so simply move it to volumes.h. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-12-05btrfs: auto enable discard=async when possibleDavid Sterba
There's a request to automatically enable async discard for capable devices. We can do that, the async mode is designed to wait for larger freed extents and is not intrusive, with limits to iops, kbps or latency. The status and tunables will be exported in /sys/fs/btrfs/FSID/discard . The automatic selection is done if there's at least one discard capable device in the filesystem (not capable devices are skipped). Mounting with any other discard option will honor that option, notably mounting with nodiscard will keep it disabled. Link: https://lore.kernel.org/linux-btrfs/CAEg-Je_b1YtdsCR0zS5XZ_SbvJgN70ezwvRwLiCZgDGLbeMB=w@mail.gmail.com/ Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2022-11-07btrfs: zoned: initialize device's zone info for seedingJohannes Thumshirn
When performing seeding on a zoned filesystem it is necessary to initialize each zoned device's btrfs_zoned_device_info structure, otherwise mounting the filesystem will cause a NULL pointer dereference. This was uncovered by fstests' testcase btrfs/163. CC: stable@vger.kernel.org # 5.15+ Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-10-24btrfs: reorder btrfs_bio for better packingDavid Sterba
After changes in commit 917f32a23501 ("btrfs: give struct btrfs_bio a real end_io handler") the layout of btrfs_bio can be improved. There are two holes and the structure size is 264 bytes on release build. By reordering the iterator we can get rid of the holes and the size is 256 bytes which fits to slabs much better. Final layout: struct btrfs_bio { unsigned int mirror_num; /* 0 4 */ struct bvec_iter iter; /* 4 20 */ u64 file_offset; /* 24 8 */ struct btrfs_device * device; /* 32 8 */ u8 * csum; /* 40 8 */ u8 csum_inline[64]; /* 48 64 */ /* --- cacheline 1 boundary (64 bytes) was 48 bytes ago --- */ btrfs_bio_end_io_t end_io; /* 112 8 */ void * private; /* 120 8 */ /* --- cacheline 2 boundary (128 bytes) --- */ struct work_struct end_io_work; /* 128 32 */ struct bio bio; /* 160 96 */ /* size: 256, cachelines: 4, members: 10 */ }; Fixes: 917f32a23501 ("btrfs: give struct btrfs_bio a real end_io handler") Signed-off-by: David Sterba <dsterba@suse.com>
2022-09-26btrfs: move btrfs_swapfile_pin into volumes.hJosef Bacik
This isn't a great spot for this, but one of the swapfile helper functions is in volumes.c, so move the struct to volumes.h. In the future when we have better separation of code there will be a more natural spot for this. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-09-26btrfs: move btrfs_pinned_by_swapfile prototype into volumes.hJosef Bacik
This is defined in volumes.c, move the prototype into volumes.h. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-09-26btrfs: give struct btrfs_bio a real end_io handlerChristoph Hellwig
Currently btrfs_bio end I/O handling is a bit of a mess. The bi_end_io handler and bi_private pointer of the embedded struct bio are both used to handle the completion of the high-level btrfs_bio and for the I/O completion for the low-level device that the embedded bio ends up being sent to. To support this bi_end_io and bi_private are saved into the btrfs_io_context structure and then restored after the bio sent to the underlying device has completed the actual I/O. Untangle this by adding an end I/O handler and private data to struct btrfs_bio for the high-level btrfs_bio based completions, and leave the actual bio bi_end_io handler and bi_private pointer entirely to the low-level device I/O. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Tested-by: Nikolay Borisov <nborisov@suse.com> Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Sterba <dsterba@suse.com>
2022-09-26btrfs: use chained bios when cloningChristoph Hellwig
The stripes_pending in the btrfs_io_context counts number of inflight low-level bios for an upper btrfs_bio. For reads this is generally one as reads are never cloned, while for writes we can trivially use the bio remaining mechanisms that is used for chained bios. To be able to make use of that mechanism, split out a separate trivial end_io handler for the cloned bios that does a minimal amount of error tracking and which then calls bio_endio on the original bio to transfer control to that, with the remaining counter making sure it is completed last. This then allows to merge btrfs_end_bioc into the original bio bi_end_io handler. To make this all work all error handling needs to happen through the bi_end_io handler, which requires a small amount of reshuffling in submit_stripe_bio so that the bio is cloned already by the time the suitability of the device is checked. This reduces the size of the btrfs_io_context and prepares splitting the btrfs_bio at the stripe boundary. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Sterba <dsterba@suse.com>
2022-09-26btrfs: pass the operation to btrfs_bio_allocChristoph Hellwig
Pass the operation to btrfs_bio_alloc, matching what bio_alloc_bioset set does. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Tested-by: Nikolay Borisov <nborisov@suse.com> Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-09-26btrfs: move btrfs_bio allocation to volumes.cChristoph Hellwig
volumes.c is the place that implements the storage layer using the btrfs_bio structure, so move the bio_set and allocation helpers there as well. To make up for the new initialization boilerplate, merge the two init/exit helpers in extent_io.c into a single one. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Tested-by: Nikolay Borisov <nborisov@suse.com> Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25btrfs: do not return errors from btrfs_map_bioChristoph Hellwig
Always consume the bio and call the end_io handler on error instead of returning an error and letting the caller handle it. This matches what the block layer submission does and avoids any confusion on who needs to handle errors. As this requires touching all the callers, rename the function to btrfs_submit_bio, which describes the functionality much better. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Tested-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25btrfs: increase direct io read size limit to 256 sectorsChristoph Hellwig
Btrfs currently limits direct I/O reads to a single sector, which goes back to commit c329861da406 ("Btrfs: don't allocate a separate csums array for direct reads") from Josef. That commit changes the direct I/O code to ".. use the private part of the io_tree for our csums.", but ten years later that isn't how checksums for direct reads work, instead they use a csums allocation on a per-btrfs_dio_private basis (which have their own performance problem for small I/O, but that will be addressed later). There is no fundamental limit in btrfs itself to limit the I/O size except for the size of the checksum array that scales linearly with the number of sectors in an I/O. Pick a somewhat arbitrary limit of 256 limits, which matches what the buffered reads typically see as the upper limit as the limit for direct I/O as well. This significantly improves direct read performance. For example a fio run doing 1 MiB aio reads with a queue depth of 1 roughly triples the throughput: Baseline: READ: bw=65.3MiB/s (68.5MB/s), 65.3MiB/s-65.3MiB/s (68.5MB/s-68.5MB/s), io=19.1GiB (20.6GB), run=300013-300013msec With this patch: READ: bw=196MiB/s (206MB/s), 196MiB/s-196MiB/s (206MB/s-206MB/s), io=57.5GiB (61.7GB), run=300006-300006msc Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25btrfs: use btrfs_raid_array to calculate number of parity stripesQu Wenruo
Use the raid table instead of hard coded values and rename the helper as it is exported. This could make later extension on RAID56 based profiles easier. 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>
2022-07-25btrfs: remove parameter dev_extent_len from scrub_stripe()Qu Wenruo
For scrub_stripe() we can easily calculate the dev extent length as we have the full info of the chunk. Thus there is no need to pass @dev_extent_len from the caller, and we introduce a helper, btrfs_calc_stripe_length(), to do the calculation from extent_map structure. 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>
2022-07-25btrfs: split discard handling out of btrfs_map_blockChristoph Hellwig
Mapping block for discard doesn't really share any code with the regular block mapping case. Split it out into an entirely separate helper that just returns an array of btrfs_discard_stripe structures and the number of stripes. This removes the need for the length field in the btrfs_io_context structure, so remove tht. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25btrfs: do not allocate a btrfs_bio for low-level biosChristoph Hellwig
The bios submitted from btrfs_map_bio don't really interact with the rest of btrfs and the only btrfs_bio member actually used in the low-level bios is the pointer to the btrfs_io_context used for endio handler. Use a union in struct btrfs_io_stripe that allows the endio handler to find the btrfs_io_context and remove the spurious ->device assignment so that a plain fs_bio_set bio can be used for the low-level bios allocated inside btrfs_map_bio. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25btrfs: remove btrfs_end_io_wqChristoph Hellwig
All reads bio that go through btrfs_map_bio need to be completed in user context. And read I/Os are the most common and timing critical in almost any file system workloads. Embed a work_struct into struct btrfs_bio and use it to complete all read bios submitted through btrfs_map, using the REQ_META flag to decide which workqueue they are placed on. This removes the need for a separate 128 byte allocation (typically rounded up to 192 bytes by slab) for all reads with a size increase of 24 bytes for struct btrfs_bio. Future patches will reorganize struct btrfs_bio to make use of this extra space for writes as well. (All sizes are based a on typical 64-bit non-debug build) Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Sterba <dsterba@suse.com>
2022-07-25btrfs: add a helper to iterate through a btrfs_bio with sector sized chunksQu Wenruo
Add a helper that works similar to __bio_for_each_segment, but instead of iterating over PAGE_SIZE chunks it iterates over each sector. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> [hch: split from a larger patch, and iterate over the offset instead of the offset bits] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> [ add parameter comments ] Signed-off-by: David Sterba <dsterba@suse.com>
2022-05-24Merge tag 'for-5.19-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs updates from David Sterba: "Features: - subpage: - support for PAGE_SIZE > 4K (previously only 64K) - make it work with raid56 - repair super block num_devices automatically if it does not match the number of device items - defrag can convert inline extents to regular extents, up to now inline files were skipped but the setting of mount option max_inline could affect the decision logic - zoned: - minimal accepted zone size is explicitly set to 4MiB - make zone reclaim less aggressive and don't reclaim if there are enough free zones - add per-profile sysfs tunable of the reclaim threshold - allow automatic block group reclaim for non-zoned filesystems, with sysfs tunables - tree-checker: new check, compare extent buffer owner against owner rootid Performance: - avoid blocking on space reservation when doing nowait direct io writes (+7% throughput for reads and writes) - NOCOW write throughput improvement due to refined locking (+3%) - send: reduce pressure to page cache by dropping extent pages right after they're processed Core: - convert all radix trees to xarray - add iterators for b-tree node items - support printk message index - user bulk page allocation for extent buffers - switch to bio_alloc API, use on-stack bios where convenient, other bio cleanups - use rw lock for block groups to favor concurrent reads - simplify workques, don't allocate high priority threads for all normal queues as we need only one - refactor scrub, process chunks based on their constraints and similarity - allocate direct io structures on stack and pass around only pointers, avoids allocation and reduces potential error handling Fixes: - fix count of reserved transaction items for various inode operations - fix deadlock between concurrent dio writes when low on free data space - fix a few cases when zones need to be finished VFS, iomap: - add helper to check if sb write has started (usable for assertions) - new helper iomap_dio_alloc_bio, export iomap_dio_bio_end_io" * tag 'for-5.19-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (173 commits) btrfs: zoned: introduce a minimal zone size 4M and reject mount btrfs: allow defrag to convert inline extents to regular extents btrfs: add "0x" prefix for unsupported optional features btrfs: do not account twice for inode ref when reserving metadata units btrfs: zoned: fix comparison of alloc_offset vs meta_write_pointer btrfs: send: avoid trashing the page cache btrfs: send: keep the current inode open while processing it btrfs: allocate the btrfs_dio_private as part of the iomap dio bio btrfs: move struct btrfs_dio_private to inode.c btrfs: remove the disk_bytenr in struct btrfs_dio_private btrfs: allocate dio_data on stack iomap: add per-iomap_iter private data iomap: allow the file system to provide a bio_set for direct I/O btrfs: add a btrfs_dio_rw wrapper btrfs: zoned: zone finish unused block group btrfs: zoned: properly finish block group on metadata write btrfs: zoned: finish block group when there are no more allocatable bytes left btrfs: zoned: consolidate zone finish functions btrfs: zoned: introduce btrfs_zoned_bg_is_full btrfs: improve error reporting in lookup_inline_extent_backref ...
2022-05-23Merge tag 'for-5.19/block-2022-05-22' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block updates from Jens Axboe: "Here are the core block changes for 5.19. This contains: - blk-throttle accounting fix (Laibin) - Series removing redundant assignments (Michal) - Expose bio cache via the bio_set, so that DM can use it (Mike) - Finish off the bio allocation interface cleanups by dealing with the weirdest member of the family. bio_kmalloc combines a kmalloc for the bio and bio_vecs with a hidden bio_init call and magic cleanup semantics (Christoph) - Clean up the block layer API so that APIs consumed by file systems are (almost) only struct block_device based, so that file systems don't have to poke into block layer internals like the request_queue (Christoph) - Clean up the blk_execute_rq* API (Christoph) - Clean up various lose end in the blk-cgroup code to make it easier to follow in preparation of reworking the blkcg assignment for bios (Christoph) - Fix use-after-free issues in BFQ when processes with merged queues get moved to different cgroups (Jan) - BFQ fixes (Jan) - Various fixes and cleanups (Bart, Chengming, Fanjun, Julia, Ming, Wolfgang, me)" * tag 'for-5.19/block-2022-05-22' of git://git.kernel.dk/linux-block: (83 commits) blk-mq: fix typo in comment bfq: Remove bfq_requeue_request_body() bfq: Remove superfluous conversion from RQ_BIC() bfq: Allow current waker to defend against a tentative one bfq: Relax waker detection for shared queues blk-cgroup: delete rcu_read_lock_held() WARN_ON_ONCE() blk-throttle: Set BIO_THROTTLED when bio has been throttled blk-cgroup: Remove unnecessary rcu_read_lock/unlock() blk-cgroup: always terminate io.stat lines block, bfq: make bfq_has_work() more accurate block, bfq: protect 'bfqd->queued' by 'bfqd->lock' block: cleanup the VM accounting in submit_bio block: Fix the bio.bi_opf comment block: reorder the REQ_ flags blk-iocost: combine local_stat and desc_stat to stat block: improve the error message from bio_check_eod block: allow passing a NULL bdev to bio_alloc_clone/bio_init_clone block: remove superfluous calls to blkcg_bio_issue_init kthread: unexport kthread_blkcg blk-cgroup: cleanup blkcg_maybe_throttle_current ...
2022-05-16btrfs: use ilog2() to replace if () branches for btrfs_bg_flags_to_raid_index()Qu Wenruo
In function btrfs_bg_flags_to_raid_index(), we use quite some if () to convert the BTRFS_BLOCK_GROUP_* bits to a index number. But the truth is, there is really no such need for so many branches at all. Since all BTRFS_BLOCK_GROUP_* flags are just one single bit set inside BTRFS_BLOCK_GROUP_PROFILES_MASK, we can easily use ilog2() to calculate their values. This calculation has an anchor point, the lowest PROFILE bit, which is RAID0. Even it's fixed on-disk format and should never change, here I added extra compile time checks to make it super safe: 1. Make sure RAID0 is always the lowest bit in PROFILE_MASK This is done by finding the first (least significant) bit set of RAID0 and PROFILE_MASK & ~RAID0. 2. Make sure RAID0 bit set beyond the highest bit of TYPE_MASK Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-05-16btrfs: move definition of btrfs_raid_types to volumes.hQu Wenruo
It's only internally used as another way to represent btrfs profiles, it's not exposed through any on-disk format, in fact this btrfs_raid_types is diverted from the on-disk format values. Furthermore, since it's internal structure, its definition can change in the future. 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>
2022-05-16btrfs: reduce width for stripe_len from u64 to u32Qu Wenruo
Currently btrfs uses fixed stripe length (64K), thus u32 is wide enough for the usage. Furthermore, even in the future we choose to enlarge stripe length to larger values, I don't believe we would want stripe as large as 4G or larger. So this patch will reduce the width for all in-memory structures and parameters, this involves: - RAID56 related function argument lists This allows us to do direct division related to stripe_len. Although we will use bits shift to replace the division anyway. - btrfs_io_geometry structure This involves one change to simplify the calculation of both @stripe_nr and @stripe_offset, using div64_u64_rem(). And add extra sanity check to make sure @stripe_offset is always small enough for u32. This saves 8 bytes for the structure. - map_lookup structure This convert @stripe_len to u32, which saves 8 bytes. (saved 4 bytes, and removed a 4-bytes hole) Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-04-19btrfs: fix direct I/O read repair for split biosChristoph Hellwig
When a bio is split in btrfs_submit_direct, dip->file_offset contains the file offset for the first bio. But this means the start value used in btrfs_check_read_dio_bio is incorrect for subsequent bios. Add a file_offset field to struct btrfs_bio to pass along the correct offset. Given that check_data_csum only uses start of an error message this means problems with this miscalculation will only show up when I/O fails or checksums mismatch. The logic was removed in f4f39fc5dc30 ("btrfs: remove btrfs_bio::logical member") but we need it due to the bio splitting. CC: stable@vger.kernel.org # 5.16+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Sterba <dsterba@suse.com>
2022-04-17btrfs: simplify ->flush_bio handlingChristoph Hellwig
Use and embedded bios that is initialized when used instead of bio_kmalloc plus bio_reset. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220406061228.410163-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-03-14btrfs: add device major-minor info in the struct btrfs_deviceAnand Jain
Internally it is common to use the major-minor number to identify a device and, at a few locations in btrfs, we use the major-minor number to match the device. So when we identify a new btrfs device through device add or device replace or device-scan/ready save the device's major-minor (dev_t) in the struct btrfs_device so that we don't have to call lookup_bdev() again. Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-03-14btrfs: match stale devices by dev_tAnand Jain
After the commit "btrfs: harden identification of the stale device", we don't have to match the device path anymore. Instead, we match the dev_t. So pass in the dev_t instead of the device path, in the call chain btrfs_forget_devices()->btrfs_free_stale_devices(). Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-01-07btrfs: remove reada infrastructureQu Wenruo
Currently there is only one user for btrfs metadata readahead, and that's scrub. But even for the single user, it's not providing the correct functionality it needs, as scrub needs reada for commit root, which current readahead can't provide. (Although it's pretty easy to add such feature). Despite this, there are some extra problems related to metadata readahead: - Duplicated feature with btrfs_path::reada - Partly duplicated feature of btrfs_fs_info::buffer_radix Btrfs already caches its metadata in buffer_radix, while readahead tries to read the tree block no matter if it's already cached. - Poor layer separation Metadata readahead works kinda at device level. This is definitely not the correct layer it should be, since metadata is at btrfs logical address space, it should not bother device at all. This brings extra chance for bugs to sneak in, while brings unnecessary complexity. - Dead code In the very beginning of scrub.c we have #undef DEBUG, rendering all the debug related code useless and unable to test. Thus here I purpose to remove the metadata readahead mechanism completely. [BENCHMARK] There is a full benchmark for the scrub performance difference using the old btrfs_reada_add() and btrfs_path::reada. For the worst case (no dirty metadata, slow HDD), there could be a 5% performance drop for scrub. For other cases (even SATA SSD), there is no distinguishable performance difference. The number is reported scrub speed, in MiB/s. The resolution is limited by the reported duration, which only has a resolution of 1 second. Old New Diff SSD 455.3 466.332 +2.42% HDD 103.927 98.012 -5.69% Comprehensive test methodology is in the cover letter of the patch. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-01-07btrfs: zoned: sink zone check into btrfs_repair_one_zoneJohannes Thumshirn
Sink zone check into btrfs_repair_one_zone() so we don't need to do it in all callers. Also as btrfs_repair_one_zone() doesn't return a sensible error, make it a boolean function and return false in case it got called on a non-zoned filesystem and true on a zoned filesystem. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26btrfs: use btrfs_get_dev_args_from_path in dev removal ioctlsJosef Bacik
For device removal and replace we call btrfs_find_device_by_devspec, which if we give it a device path and nothing else will call btrfs_get_dev_args_from_path, which opens the block device and reads the super block and then looks up our device based on that. However at this point we're holding the sb write "lock", so reading the block device pulls in the dependency of ->open_mutex, which produces the following lockdep splat ====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc2+ #405 Not tainted ------------------------------------------------------ losetup/11576 is trying to acquire lock: ffff9bbe8cded938 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0 but task is already holding lock: ffff9bbe88e4fc68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 lo_open+0x28/0x60 [loop] blkdev_get_whole+0x25/0xf0 blkdev_get_by_dev.part.0+0x168/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x161/0x390 path_openat+0x3cc/0xa20 do_filp_open+0x96/0x120 do_sys_openat2+0x7b/0x130 __x64_sys_openat+0x46/0x70 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #3 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 blkdev_get_by_dev.part.0+0x56/0x3c0 blkdev_get_by_path+0x98/0xa0 btrfs_get_bdev_and_sb+0x1b/0xb0 btrfs_find_device_by_devspec+0x12b/0x1c0 btrfs_rm_device+0x127/0x610 btrfs_ioctl+0x2a31/0x2e70 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #2 (sb_writers#12){.+.+}-{0:0}: lo_write_bvec+0xc2/0x240 [loop] loop_process_work+0x238/0xd00 [loop] process_one_work+0x26b/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x245/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #0 ((wq_completion)loop0){+.+.}-{0:0}: __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 flush_workqueue+0x91/0x5e0 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&lo->lo_mutex); lock(&disk->open_mutex); lock(&lo->lo_mutex); lock((wq_completion)loop0); *** DEADLOCK *** 1 lock held by losetup/11576: #0: ffff9bbe88e4fc68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] stack backtrace: CPU: 0 PID: 11576 Comm: losetup Not tainted 5.14.0-rc2+ #405 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack_lvl+0x57/0x72 check_noncircular+0xcf/0xf0 ? stack_trace_save+0x3b/0x50 __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 ? flush_workqueue+0x67/0x5e0 ? lockdep_init_map_type+0x47/0x220 flush_workqueue+0x91/0x5e0 ? flush_workqueue+0x67/0x5e0 ? verify_cpu+0xf0/0x100 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] ? blkdev_ioctl+0x8d/0x2a0 block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f31b02404cb Instead what we want to do is populate our device lookup args before we grab any locks, and then pass these args into btrfs_rm_device(). From there we can find the device and do the appropriate removal. Suggested-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26btrfs: add a btrfs_get_dev_args_from_path helperJosef Bacik
We are going to want to populate our device lookup args outside of any locks and then do the actual device lookup later, so add a helper to do this work and make btrfs_find_device_by_devspec() use this helper for now. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26btrfs: handle device lookup with btrfs_dev_lookup_argsJosef Bacik
We have a lot of device lookup functions that all do something slightly different. Clean this up by adding a struct to hold the different lookup criteria, and then pass this around to btrfs_find_device() so it can do the proper matching based on the lookup criteria. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>