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path: root/fs/btrfs/zoned.c
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2021-06-22btrfs: fix typos in commentsDavid Sterba
Fix typos that have snuck in since the last round. Found by codespell. Signed-off-by: David Sterba <dsterba@suse.com>
2021-06-21btrfs: zoned: factor out zoned device lookupJohannes Thumshirn
To be able to construct a zone append bio we need to look up the btrfs_device. The code doing the chunk map lookup to get the device is present in btrfs_submit_compressed_write and submit_extent_page. Factor out the lookup calls into a helper and use it in the submission paths. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-06-21btrfs: zoned: bail out if we can't read a reliable write pointerJohannes Thumshirn
If we can't read a reliable write pointer from a sequential zone fail creating the block group with an I/O error. Also if the read write pointer is beyond the end of the respective zone, fail the creation of the block group on this zone with an I/O error. While this could also happen in real world scenarios with misbehaving drives, this issue addresses a problem uncovered by fstests' test case generic/475. CC: stable@vger.kernel.org # 5.12+ Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-06-21btrfs: zoned: print message when zone sanity check type failsNaohiro Aota
This extends patch 784daf2b9628 ("btrfs: zoned: sanity check zone type"), the message was supposed to be there but was lost during merge. We want to make the error noticeable so add it. Fixes: 784daf2b9628 ("btrfs: zoned: sanity check zone type") CC: stable@vger.kernel.org # 5.12+ Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-06-04btrfs: zoned: fix zone number to sector/physical calculationNaohiro Aota
In btrfs_get_dev_zone_info(), we have "u32 sb_zone" and calculate "sector_t sector" by shifting it. But, this "sector" is calculated in 32bit, leading it to be 0 for the 2nd superblock copy. Since zone number is u32, shifting it to sector (sector_t) or physical address (u64) can easily trigger a missing cast bug like this. This commit introduces helpers to convert zone number to sector/LBA, so we won't fall into the same pitfall again. Reported-by: Dmitry Fomichev <Dmitry.Fomichev@wdc.com> Fixes: 12659251ca5d ("btrfs: implement log-structured superblock for ZONED mode") CC: stable@vger.kernel.org # 5.11+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-05-20btrfs: zoned: pass start block to btrfs_use_zone_appendJohannes Thumshirn
btrfs_use_zone_append only needs the passed in extent_map's block_start member, so there's no need to pass in the full extent map. This also enables the use of btrfs_use_zone_append in places where we only have a start byte but no extent_map. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-05-04btrfs: zoned: sanity check zone typeNaohiro Aota
The fstests test case generic/475 creates a dm-linear device that gets changed to a dm-error device. This leads to errors in loading the block group's zone information when running on a zoned file system, ultimately resulting in a list corruption. When running on a kernel with list debugging enabled this leads to the following crash. BTRFS: error (device dm-2) in cleanup_transaction:1953: errno=-5 IO failure kernel BUG at lib/list_debug.c:54! invalid opcode: 0000 [#1] SMP PTI CPU: 1 PID: 2433 Comm: umount Tainted: G W 5.12.0+ #1018 RIP: 0010:__list_del_entry_valid.cold+0x1d/0x47 RSP: 0018:ffffc90001473df0 EFLAGS: 00010296 RAX: 0000000000000054 RBX: ffff8881038fd000 RCX: ffffc90001473c90 RDX: 0000000100001a31 RSI: 0000000000000003 RDI: 0000000000000003 RBP: ffff888308871108 R08: 0000000000000003 R09: 0000000000000001 R10: 3961373532383838 R11: 6666666620736177 R12: ffff888308871000 R13: ffff8881038fd088 R14: ffff8881038fdc78 R15: dead000000000100 FS: 00007f353c9b1540(0000) GS:ffff888627d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f353cc2c710 CR3: 000000018e13c000 CR4: 00000000000006a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: btrfs_free_block_groups+0xc9/0x310 [btrfs] close_ctree+0x2ee/0x31a [btrfs] ? call_rcu+0x8f/0x270 ? mutex_lock+0x1c/0x40 generic_shutdown_super+0x67/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x31/0x90 cleanup_mnt+0x13e/0x1b0 task_work_run+0x63/0xb0 exit_to_user_mode_loop+0xd9/0xe0 exit_to_user_mode_prepare+0x3e/0x60 syscall_exit_to_user_mode+0x1d/0x50 entry_SYSCALL_64_after_hwframe+0x44/0xae As dm-error has no support for zones, btrfs will run it's zone emulation mode on this device. The zone emulation mode emulates conventional zones, so bail out if the zone bitmap that gets populated on mount sees the zone as sequential while we're thinking it's a conventional zone when creating a block group. Note: this scenario is unlikely in a real wold application and can only happen by this (ab)use of device-mapper targets. CC: stable@vger.kernel.org # 5.12+ Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-19btrfs: zoned: fail mount if the device does not support zone appendJohannes Thumshirn
For zoned btrfs, zone append is mandatory to write to a sequential write only zone, otherwise parallel writes to the same zone could result in unaligned write errors. If a zoned block device does not support zone append (e.g. a dm-crypt zoned device using a non-NULL IV cypher), fail to mount. CC: stable@vger.kernel.org # 5.12 Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-04-11Merge tag 'for-5.12-rc6-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fix from David Sterba: "One more patch that we'd like to get to 5.12 before release. It's changing where and how the superblock is stored in the zoned mode. It is an on-disk format change but so far there are no implications for users as the proper mkfs support hasn't been merged and is waiting for the kernel side to settle. Until now, the superblocks were derived from the zone index, but zone size can differ per device. This is changed to be based on fixed offset values, to make it independent of the device zone size. The work on that got a bit delayed, we discussed the exact locations to support potential device sizes and usecases. (Partially delayed also due to my vacation.) Having that in the same release where the zoned mode is declared usable is highly desired, there are userspace projects that need to be updated to recognize the feature. Pushing that to the next release would make things harder to test" * tag 'for-5.12-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: zoned: move superblock logging zone location
2021-04-10btrfs: zoned: move superblock logging zone locationNaohiro Aota
Moves the location of the superblock logging zones. The new locations of the logging zones are now determined based on fixed block addresses instead of on fixed zone numbers. The old placement method based on fixed zone numbers causes problems when one needs to inspect a file system image without access to the drive zone information. In such case, the super block locations cannot be reliably determined as the zone size is unknown. By locating the superblock logging zones using fixed addresses, we can scan a dumped file system image without the zone information since a super block copy will always be present at or after the fixed known locations. Introduce the following three pairs of zones containing fixed offset locations, regardless of the device zone size. - primary superblock: offset 0B (and the following zone) - first copy: offset 512G (and the following zone) - Second copy: offset 4T (4096G, and the following zone) If a logging zone is outside of the disk capacity, we do not record the superblock copy. The first copy position is much larger than for a non-zoned filesystem, which is at 64M. This is to avoid overlapping with the log zones for the primary superblock. This higher location is arbitrary but allows supporting devices with very large zone sizes, plus some space around in between. Such large zone size is unrealistic and very unlikely to ever be seen in real devices. Currently, SMR disks have a zone size of 256MB, and we are expecting ZNS drives to be in the 1-4GB range, so this limit gives us room to breathe. For now, we only allow zone sizes up to 8GB. The maximum zone size that would still fit in the space is 256G. The fixed location addresses are somewhat arbitrary, with the intent of maintaining superblock reliability for smaller and larger devices, with the preference for the latter. For this reason, there are two superblocks under the first 1T. This should cover use cases for physical devices and for emulated/device-mapper devices. The superblock logging zones are reserved for superblock logging and never used for data or metadata blocks. Note that we only reserve the two zones per primary/copy actually used for superblock logging. We do not reserve the ranges of zones possibly containing superblocks with the largest supported zone size (0-16GB, 512G-528GB, 4096G-4112G). The zones containing the fixed location offsets used to store superblocks on a non-zoned volume are also reserved to avoid confusion. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-03-05Merge tag 'for-5.12-rc1-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "More regression fixes and stabilization. Regressions: - zoned mode - count zone sizes in wider int types - fix space accounting for read-only block groups - subpage: fix page tail zeroing Fixes: - fix spurious warning when remounting with free space tree - fix warning when creating a directory with smack enabled - ioctl checks for qgroup inheritance when creating a snapshot - qgroup - fix missing unlock on error path in zero range - fix amount of released reservation on error - fix flushing from unsafe context with open transaction, potentially deadlocking - minor build warning fixes" * tag 'for-5.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: zoned: do not account freed region of read-only block group as zone_unusable btrfs: zoned: use sector_t for zone sectors btrfs: subpage: fix the false data csum mismatch error btrfs: fix warning when creating a directory with smack enabled btrfs: don't flush from btrfs_delayed_inode_reserve_metadata btrfs: export and rename qgroup_reserve_meta btrfs: free correct amount of space in btrfs_delayed_inode_reserve_metadata btrfs: fix spurious free_space_tree remount warning btrfs: validate qgroup inherit for SNAP_CREATE_V2 ioctl btrfs: unlock extents in btrfs_zero_range in case of quota reservation errors btrfs: ref-verify: use 'inline void' keyword ordering
2021-03-04btrfs: zoned: use sector_t for zone sectorsNaohiro Aota
We need to use sector_t for zone_sectors, or it would set the zone size to zero when the size >= 4GB (= 2^24 sectors) by shifting the zone_sectors value by SECTOR_SHIFT. We're assuming zones sizes up to 8GiB. Fixes: 5b316468983d ("btrfs: get zone information of zoned block devices") Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-21Merge tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block updates from Jens Axboe: "Another nice round of removing more code than what is added, mostly due to Christoph's relentless pursuit of tech debt removal/cleanups. This pull request contains: - Two series of BFQ improvements (Paolo, Jan, Jia) - Block iov_iter improvements (Pavel) - bsg error path fix (Pan) - blk-mq scheduler improvements (Jan) - -EBUSY discard fix (Jan) - bvec allocation improvements (Ming, Christoph) - bio allocation and init improvements (Christoph) - Store bdev pointer in bio instead of gendisk + partno (Christoph) - Block trace point cleanups (Christoph) - hard read-only vs read-only split (Christoph) - Block based swap cleanups (Christoph) - Zoned write granularity support (Damien) - Various fixes/tweaks (Chunguang, Guoqing, Lei, Lukas, Huhai)" * tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block: (104 commits) mm: simplify swapdev_block sd_zbc: clear zone resources for non-zoned case block: introduce blk_queue_clear_zone_settings() zonefs: use zone write granularity as block size block: introduce zone_write_granularity limit block: use blk_queue_set_zoned in add_partition() nullb: use blk_queue_set_zoned() to setup zoned devices nvme: cleanup zone information initialization block: document zone_append_max_bytes attribute block: use bi_max_vecs to find the bvec pool md/raid10: remove dead code in reshape_request block: mark the bio as cloned in bio_iov_bvec_set block: set BIO_NO_PAGE_REF in bio_iov_bvec_set block: remove a layer of indentation in bio_iov_iter_get_pages block: turn the nr_iovecs argument to bio_alloc* into an unsigned short block: remove the 1 and 4 vec bvec_slabs entries block: streamline bvec_alloc block: factor out a bvec_alloc_gfp helper block: move struct biovec_slab to bio.c block: reuse BIO_INLINE_VECS for integrity bvecs ...
2021-02-09btrfs: zoned: support dev-replace in zoned filesystemsNaohiro Aota
This is 4/4 patch to implement device-replace on zoned filesystems. Even after the copying is done, the write pointers of the source device and the destination device may not be synchronized. For example, when the last allocated extent is freed before device-replace process, the extent is not copied, leaving a hole there. Synchronize the write pointers by writing zeroes to the destination device. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-09btrfs: zoned: implement copying for zoned device-replaceNaohiro Aota
This is 3/4 patch to implement device-replace on zoned filesystems. This commit implements copying. To do this, it tracks the write pointer during the device replace process. As device-replace's copy process is smart enough to only copy used extents on the source device, we have to fill the gap to honor the sequential write requirement in the target device. The device-replace process on zoned filesystems must copy or clone all the extents in the source device exactly once. So, we need to ensure allocations started just before the dev-replace process to have their corresponding extent information in the B-trees. finish_extent_writes_for_zoned() implements that functionality, which basically is the removed code in the commit 042528f8d840 ("Btrfs: fix block group remaining RO forever after error during device replace"). Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-09btrfs: zoned: implement cloning for zoned device-replaceNaohiro Aota
This is 2/4 patch to implement device replace for zoned filesystems. In zoned mode, a block group must be either copied (from the source device to the target device) or cloned (to both devices). Implement the cloning part. If a block group targeted by an IO is marked to copy, we should not clone the IO to the destination device, because the block group is eventually copied by the replace process. This commit also handles cloning of device reset. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-09btrfs: zoned: serialize metadata IONaohiro Aota
We cannot use zone append for writing metadata, because the B-tree nodes have references to each other using logical address. Without knowing the address in advance, we cannot construct the tree in the first place. So we need to serialize write IOs for metadata. We cannot add a mutex around allocation and submission because metadata blocks are allocated in an earlier stage to build up B-trees. Add a zoned_meta_io_lock and hold it during metadata IO submission in btree_write_cache_pages() to serialize IOs. Furthermore, this adds a per-block group metadata IO submission pointer "meta_write_pointer" to ensure sequential writing, which can break when attempting to write back blocks in an unfinished transaction. If the writing out failed because of a hole and the write out is for data integrity (WB_SYNC_ALL), it returns EAGAIN. A caller like fsync() code should handle this properly e.g. by falling back to a full transaction commit. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-09btrfs: zoned: use ZONE_APPEND write for zoned modeNaohiro Aota
Enable zone append writing for zoned mode. When using zone append, a bio is issued to the start of a target zone and the device decides to place it inside the zone. Upon completion the device reports the actual written position back to the host. Three parts are necessary to enable zone append mode. First, modify the bio to use REQ_OP_ZONE_APPEND in btrfs_submit_bio_hook() and adjust the bi_sector to point the beginning of the zone. Second, record the returned physical address (and disk/partno) to the ordered extent in end_bio_extent_writepage() after the bio has been completed. We cannot resolve the physical address to the logical address because we can neither take locks nor allocate a buffer in this end_bio context. So, we need to record the physical address to resolve it later in btrfs_finish_ordered_io(). And finally, rewrite the logical addresses of the extent mapping and checksum data according to the physical address using btrfs_rmap_block. If the returned address matches the originally allocated address, we can skip this rewriting process. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-09btrfs: zoned: cache if block group is on a sequential zoneJohannes Thumshirn
On a zoned filesystem, cache if a block group is on a sequential write only zone. On sequential write only zones, we can use REQ_OP_ZONE_APPEND for writing data, therefore provide btrfs_use_zone_append() to figure out if IO is targeting a sequential write only zone and we can use REQ_OP_ZONE_APPEND for data writing. 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>
2021-02-09btrfs: zoned: redirty released extent buffersNaohiro Aota
Tree manipulating operations like merging nodes often release once-allocated tree nodes. Such nodes are cleaned so that pages in the node are not uselessly written out. On zoned volumes, however, such optimization blocks the following IOs as the cancellation of the write out of the freed blocks breaks the sequential write sequence expected by the device. Introduce a list of clean and unwritten extent buffers that have been released in a transaction. Redirty the buffers so that btree_write_cache_pages() can send proper bios to the devices. Besides it clears the entire content of the extent buffer not to confuse raw block scanners e.g. 'btrfs check'. By clearing the content, csum_dirty_buffer() complains about bytenr mismatch, so avoid the checking and checksum using newly introduced buffer flag EXTENT_BUFFER_NO_CHECK. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-09btrfs: zoned: track unusable bytes for zonesNaohiro Aota
In a zoned filesystem a once written then freed region is not usable until the underlying zone has been reset. So we need to distinguish such unusable space from usable free space. Therefore we need to introduce the "zone_unusable" field to the block group structure, and "bytes_zone_unusable" to the space_info structure to track the unusable space. Pinned bytes are always reclaimed to the unusable space. But, when an allocated region is returned before using e.g., the block group becomes read-only between allocation time and reservation time, we can safely return the region to the block group. For the situation, this commit introduces "btrfs_add_free_space_unused". This behaves the same as btrfs_add_free_space() on regular filesystem. On zoned filesystems, it rewinds the allocation offset. Because the read-only bytes tracks free but unusable bytes when the block group is read-only, we need to migrate the zone_unusable bytes to read-only bytes when a block group is marked read-only. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-09btrfs: zoned: calculate allocation offset for conventional zonesNaohiro Aota
Conventional zones do not have a write pointer, so we cannot use it to determine the allocation offset for sequential allocation if a block group contains a conventional zone. But instead, we can consider the end of the highest addressed extent in the block group for the allocation offset. For new block group, we cannot calculate the allocation offset by consulting the extent tree, because it can cause deadlock by taking extent buffer lock after chunk mutex, which is already taken in btrfs_make_block_group(). Since it is a new block group anyways, we can simply set the allocation offset to 0. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-09btrfs: zoned: load zone's allocation offsetNaohiro Aota
A zoned filesystem must allocate blocks at the zones' write pointer. The device's write pointer position can be mapped to a logical address within a block group. To facilitate this, add an "alloc_offset" to the block-group to track the logical addresses of the write pointer. This logical address is populated in btrfs_load_block_group_zone_info() from the write pointers of corresponding zones. For now, zoned filesystems the single profile. Supporting non-single profile with zone append writing is not trivial. For example, in the DUP profile, we send a zone append writing IO to two zones on a device. The device reply with written LBAs for the IOs. If the offsets of the returned addresses from the beginning of the zone are different, then it results in different logical addresses. We need fine-grained logical to physical mapping to support such separated physical address issue. Since it should require additional metadata type, disable non-single profiles for now. This commit supports the case all the zones in a block group are sequential. The next patch will handle the case having a conventional zone. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-09btrfs: zoned: implement zoned chunk allocatorNaohiro Aota
Implement a zoned chunk and device extent allocator. One device zone becomes a device extent so that a zone reset affects only this device extent and does not change the state of blocks in the neighbor device extents. To implement the allocator, we need to extend the following functions for a zoned filesystem. - init_alloc_chunk_ctl - dev_extent_search_start - dev_extent_hole_check - decide_stripe_size init_alloc_chunk_ctl_zoned() is mostly the same as regular one. It always set the stripe_size to the zone size and aligns the parameters to the zone size. dev_extent_search_start() only aligns the start offset to zone boundaries. We don't care about the first 1MB like in regular filesystem because we anyway reserve the first two zones for superblock logging. dev_extent_hole_check_zoned() checks if zones in given hole are either conventional or empty sequential zones. Also, it skips zones reserved for superblock logging. With the change to the hole, the new hole may now contain pending extents. So, in this case, loop again to check that. Finally, decide_stripe_size_zoned() should shrink the number of devices instead of stripe size because we need to honor stripe_size == zone_size. Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-09btrfs: zoned: allow zoned filesystems on non-zoned block devicesJohannes Thumshirn
Run a zoned filesystem on non-zoned devices. This is done by "slicing up" the block device into static sized chunks and fake a conventional zone on each of them. The emulated zone size is determined from the size of device extent. This is mainly aimed at testing of zoned filesystems, i.e. the zoned chunk allocator, on regular block devices. Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-09btrfs: zoned: do not load fs_info::zoned from incompat flagJohannes Thumshirn
Don't set the zoned flag in fs_info as soon as we're encountering the incompat filesystem flag for a zoned filesystem on mount. The zoned flag in fs_info is in a union together with the zone_size, so setting it too early will result in setting an incorrect zone_size as well. Once the correct zone_size is read from the device, we can rely on the zoned flag in fs_info as well to determine if the filesystem is zoned. Reviewed-by: Anand Jain <anand.jain@oracle.com> 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>
2021-02-09btrfs: zoned: use regular super block location on zone emulationNaohiro Aota
A zoned filesystem currently has a superblock at the beginning of the superblock logging zones if the zones are conventional. This difference in superblock position causes a chicken-and-egg problem for filesystems with emulated zones. Since the device is a regular (non-zoned) device, we cannot know if the filesystem is regular or zoned while reading the superblock. But, to load the superblock, we need to see if it is emulated zoned or not. Place the superblocks at the same location as they are on regular filesystem on regular devices to solve the problem. It is possible because it's ensured that all the superblock locations are at an (emulated) conventional zone on regular devices. Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-09btrfs: zoned: defer loading zone info after opening treesNaohiro Aota
This is a preparation patch to implement zone emulation on a regular device. To emulate a zoned filesystem on a regular (non-zoned) device, we need to decide an emulated zone size. Instead of making it a compile-time static value, we'll make it configurable at mkfs time. Since we have one zone == one device extent restriction, we can determine the emulated zone size from the size of a device extent. We can extend btrfs_get_dev_zone_info() to show a regular device filled with conventional zones once the zone size is decided. The current call site of btrfs_get_dev_zone_info() during the mount process is earlier than loading the file system trees so that we don't know the size of a device extent at this point. Thus we can't slice a regular device to conventional zones. This patch introduces btrfs_get_dev_zone_info_all_devices to load the zone info for all the devices. And, it places this function in open_ctree() after loading the trees. Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-08btrfs: zoned: remove unused variable in btrfs_sb_log_location_bdevNikolay Borisov
This fixes warning: fs/btrfs/zoned.c:491:6: warning: variable ‘zone_size’ set but not used [-Wunused-but-set-variable] 491 | u64 zone_size; which got introduced in 12659251ca5d ("btrfs: implement log-structured superblock for ZONED mode"). We'll enable the warning by default and want clean build until the relevant zoned patches land. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-12-16Merge tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block updates from Jens Axboe: "Another series of killing more code than what is being added, again thanks to Christoph's relentless cleanups and tech debt tackling. This contains: - blk-iocost improvements (Baolin Wang) - part0 iostat fix (Jeffle Xu) - Disable iopoll for split bios (Jeffle Xu) - block tracepoint cleanups (Christoph Hellwig) - Merging of struct block_device and hd_struct (Christoph Hellwig) - Rework/cleanup of how block device sizes are updated (Christoph Hellwig) - Simplification of gendisk lookup and removal of block device aliasing (Christoph Hellwig) - Block device ioctl cleanups (Christoph Hellwig) - Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig) - Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig) - sbitmap improvements (Pavel Begunkov) - Hybrid polling fix (Pavel Begunkov) - bvec iteration improvements (Pavel Begunkov) - Zone revalidation fixes (Damien Le Moal) - blk-throttle limit fix (Yu Kuai) - Various little fixes" * tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits) blk-mq: fix msec comment from micro to milli seconds blk-mq: update arg in comment of blk_mq_map_queue blk-mq: add helper allocating tagset->tags Revert "block: Fix a lockdep complaint triggered by request queue flushing" nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class blk-mq: add new API of blk_mq_hctx_set_fq_lock_class block: disable iopoll for split bio block: Improve blk_revalidate_disk_zones() checks sbitmap: simplify wrap check sbitmap: replace CAS with atomic and sbitmap: remove swap_lock sbitmap: optimise sbitmap_deferred_clear() blk-mq: skip hybrid polling if iopoll doesn't spin blk-iocost: Factor out the base vrate change into a separate function blk-iocost: Factor out the active iocgs' state check into a separate function blk-iocost: Move the usage ratio calculation to the correct place blk-iocost: Remove unnecessary advance declaration blk-iocost: Fix some typos in comments blktrace: fix up a kerneldoc comment block: remove the request_queue to argument request based tracepoints ...
2020-12-09btrfs: implement log-structured superblock for ZONED modeNaohiro Aota
Superblock (and its copies) is the only data structure in btrfs which has a fixed location on a device. Since we cannot overwrite in a sequential write required zone, we cannot place superblock in the zone. One easy solution is limiting superblock and copies to be placed only in conventional zones. However, this method has two downsides: one is reduced number of superblock copies. The location of the second copy of superblock is 256GB, which is in a sequential write required zone on typical devices in the market today. So, the number of superblock and copies is limited to be two. Second downside is that we cannot support devices which have no conventional zones at all. To solve these two problems, we employ superblock log writing. It uses two adjacent zones as a circular buffer to write updated superblocks. Once the first zone is filled up, start writing into the second one. Then, when both zones are filled up and before starting to write to the first zone again, it reset the first zone. We can determine the position of the latest superblock by reading write pointer information from a device. One corner case is when both zones are full. For this situation, we read out the last superblock of each zone, and compare them to determine which zone is older. The following zones are reserved as the circular buffer on ZONED btrfs. - The primary superblock: zones 0 and 1 - The first copy: zones 16 and 17 - The second copy: zones 1024 or zone at 256GB which is minimum, and next to it If these reserved zones are conventional, superblock is written fixed at the start of the zone without logging. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-12-09btrfs: disallow mixed-bg in ZONED modeNaohiro Aota
Placing both data and metadata in a block group is impossible in ZONED mode. For data, we can allocate a space for it and write it immediately after the allocation. For metadata, however, we cannot do that, because the logical addresses are recorded in other metadata buffers to build up the trees. As a result, a data buffer can be placed after a metadata buffer, which is not written yet. Writing out the data buffer will break the sequential write rule. Check and disallow MIXED_BG with ZONED mode. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-12-09btrfs: disallow NODATACOW in ZONED modeNaohiro Aota
NODATACOW implies overwriting the file data on a device, which is impossible in sequential required zones. Disable NODATACOW globally with mount option and per-file NODATACOW attribute by masking FS_NOCOW_FL. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-12-09btrfs: disallow space_cache in ZONED modeNaohiro Aota
As updates to the space cache v1 are in-place, the space cache cannot be located over sequential zones and there is no guarantees that the device will have enough conventional zones to store this cache. Resolve this problem by disabling completely the space cache v1. This does not introduce any problems with sequential block groups: all the free space is located after the allocation pointer and no free space before the pointer. There is no need to have such cache. Note: we can technically use free-space-tree (space cache v2) on ZONED mode. But, since ZONED mode now always allocates extents in a block group sequentially regardless of underlying device zone type, it's no use to enable and maintain the tree. For the same reason, NODATACOW is also disabled. In summary, ZONED will disable: | Disabled features | Reason | |-------------------+-----------------------------------------------------| | RAID/DUP | Cannot handle two zone append writes to different | | | zones | |-------------------+-----------------------------------------------------| | space_cache (v1) | In-place updating | | NODATACOW | In-place updating | |-------------------+-----------------------------------------------------| | fallocate | Reserved extent will be a write hole | |-------------------+-----------------------------------------------------| | MIXED_BG | Allocated metadata region will be write holes for | | | data writes | Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-12-09btrfs: introduce max_zone_append_sizeNaohiro Aota
The zone append write command has a maximum IO size restriction it accepts. This is because a zone append write command cannot be split, as we ask the device to place the data into a specific target zone and the device responds with the actual written location of the data. Introduce max_zone_append_size to zone_info and fs_info to track the value, so we can limit all I/O to a zoned block device that we want to write using the zone append command to the device's limits. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-12-09btrfs: check and enable ZONED modeNaohiro Aota
Introduce function btrfs_check_zoned_mode() to check if ZONED flag is enabled on the file system and if the file system consists of zoned devices with equal zone size. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-12-09btrfs: get zone information of zoned block devicesNaohiro Aota
If a zoned block device is found, get its zone information (number of zones and zone size). To avoid costly run-time zone report commands to test the device zones type during block allocation, attach the seq_zones bitmap to the device structure to indicate if a zone is sequential or accept random writes. Also it attaches the empty_zones bitmap to indicate if a zone is empty or not. This patch also introduces the helper function btrfs_dev_is_sequential() to test if the zone storing a block is a sequential write required zone and btrfs_dev_is_empty_zone() to test if the zone is a empty zone. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>