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path: root/fs/btrfs/volumes.h
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2023-04-17btrfs: introduce a new helper to submit write bio for repairGravatar Qu Wenruo 1-0/+3
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 valueGravatar Qu Wenruo 1-4/+15
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 stripesGravatar Qu Wenruo 1-12/+14
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_contextsGravatar Qu Wenruo 1-5/+49
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_LENGravatar Qu Wenruo 1-2/+5
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_geometryGravatar Christoph Hellwig 1-18/+0
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 fileGravatar Christoph Hellwig 1-105/+5
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.hGravatar Christoph Hellwig 1-1/+1
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 betterGravatar Qu Wenruo 1-0/+9
[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()Gravatar Qu Wenruo 1-3/+22
[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()Gravatar Anand Jain 1-2/+2
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.hGravatar Josef Bacik 1-0/+8
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 possibleGravatar David Sterba 1-0/+2
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 seedingGravatar Johannes Thumshirn 1-1/+1
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 packingGravatar David Sterba 1-1/+1
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.hGravatar Josef Bacik 1-0/+25
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.hGravatar Josef Bacik 1-0/+2
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 handlerGravatar Christoph Hellwig 1-4/+16
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 cloningGravatar Christoph Hellwig 1-1/+0
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_allocGravatar Christoph Hellwig 1-1/+1
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.cGravatar Christoph Hellwig 1-0/+6
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_bioGravatar Christoph Hellwig 1-2/+1
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 sectorsGravatar Christoph Hellwig 1-0/+7
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 stripesGravatar Qu Wenruo 1-0/+1
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()Gravatar Qu Wenruo 1-0/+1
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_blockGravatar Christoph Hellwig 1-1/+9
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 biosGravatar Christoph Hellwig 1-1/+6
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_wqGravatar Christoph Hellwig 1-0/+3
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 chunksGravatar Qu Wenruo 1-0/+16
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 ↵Gravatar Linus Torvalds 1-4/+38
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-blockGravatar Linus Torvalds 1-2/+2
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()Gravatar Qu Wenruo 1-9/+30
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.hGravatar Qu Wenruo 1-0/+13
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 u32Gravatar Qu Wenruo 1-4/+4
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 biosGravatar Christoph Hellwig 1-0/+3
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 handlingGravatar Christoph Hellwig 1-2/+2
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_deviceGravatar Anand Jain 1-0/+5
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_tGravatar Anand Jain 1-1/+1
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 infrastructureGravatar Qu Wenruo 1-7/+0
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_zoneGravatar Johannes Thumshirn 1-1/+1
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 ioctlsGravatar Josef Bacik 1-1/+1
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 helperGravatar Josef Bacik 1-0/+4
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_argsGravatar Josef Bacik 1-2/+18
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>
2021-10-26btrfs: add comments for device counts in struct btrfs_fs_devicesGravatar Anand Jain 1-0/+19
A bug was was checking a wrong device count before we delete the struct btrfs_fs_devices in btrfs_rm_device(). To avoid future confusion and easy reference add a comment about the various device counts that we have in the struct btrfs_fs_devices. Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26btrfs: remove btrfs_bio::logical memberGravatar Qu Wenruo 1-1/+0
The member btrfs_bio::logical is only initialized by two call sites: - btrfs_repair_one_sector() No corresponding site to utilize it. - btrfs_submit_direct() The corresponding site to utilize it is btrfs_check_read_dio_bio(). However for btrfs_check_read_dio_bio(), we can grab the file_offset from btrfs_dio_private::file_offset directly. Thus it turns out we don't really need that btrfs_bio::logical member at all. For btrfs_bio, the logical bytenr can be fetched from its bio->bi_iter.bi_sector directly. So let's just remove the member to save 8 bytes for structure btrfs_bio. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26btrfs: rename struct btrfs_io_bio to btrfs_bioGravatar Qu Wenruo 1-15/+14
Previously we had "struct btrfs_bio", which records IO context for mirrored IO and RAID56, and "strcut btrfs_io_bio", which records extra btrfs specific info for logical bytenr bio. With "btrfs_bio" renamed to "btrfs_io_context", we are safe to rename "btrfs_io_bio" to "btrfs_bio" which is a more suitable name now. The struct btrfs_bio changes meaning by this commit. There was a suggested name like btrfs_logical_bio but it's a bit long and we'd prefer to use a shorter name. This could be a concern for backports to older kernels where the different meaning could possibly cause confusion or bugs. Comparing the new and old structures, there's no overlap among the struct members so a build would break in case of incorrect backport. We haven't had many backports to bio code anyway so this is more of a theoretical cause of bugs and a matter of precaution but we'll need to keep the semantic change in mind. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26btrfs: rename btrfs_bio to btrfs_io_contextGravatar Qu Wenruo 1-11/+27
The structure btrfs_bio is used by two different sites: - bio->bi_private for mirror based profiles For those profiles (SINGLE/DUP/RAID1*/RAID10), this structures records how many mirrors are still pending, and save the original endio function of the bio. - RAID56 code In that case, RAID56 only utilize the stripes info, and no long uses that to trace the pending mirrors. So btrfs_bio is not always bind to a bio, and contains more info for IO context, thus renaming it will make the naming less confusing. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26btrfs: convert latest_bdev type to btrfs_device and renameGravatar Anand Jain 1-1/+5
In preparation to fix a bug in btrfs_show_devname(). Convert fs_devices::latest_bdev type from struct block_device to struct btrfs_device and, rename the member to fs_devices::latest_dev. So that btrfs_show_devname() can use fs_devices::latest_dev::name. Tested-by: Su Yue <l@damenly.su> Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-26btrfs: rename and switch to bool btrfs_chunk_readonlyGravatar Anand Jain 1-1/+1
btrfs_chunk_readonly() checks if the given chunk is writeable. It returns 1 for readonly, and 0 for writeable. So the return argument type bool shall suffice instead of the current type int. Also, rename btrfs_chunk_readonly() to btrfs_chunk_writeable() as we check if the bg is writeable, and helps to keep the logic at the parent function simpler to understand. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-10-25btrfs: rename btrfs_alloc_chunk to btrfs_create_chunkGravatar Nikolay Borisov 1-1/+1
The user facing function used to allocate new chunks is btrfs_chunk_alloc, unfortunately there is yet another similar sounding function - btrfs_alloc_chunk. This creates confusion, especially since the latter function can be considered "private" in the sense that it implements the first stage of chunk creation and as such is called by btrfs_chunk_alloc. To avoid the awkwardness that comes with having similarly named but distinctly different in their purpose function rename btrfs_alloc_chunk to btrfs_create_chunk, given that the main purpose of this function is to orchestrate the whole process of allocating a chunk - reserving space into devices, deciding on characteristics of the stripe size and creating the in-memory structures. Reviewed-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>