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2025-03-10xfs: cleanup mapping tmpfs folios into the buffer cacheChristoph Hellwig
Directly assign b_addr based on the tmpfs folios without a detour through pages, reuse the folio_put path used for non-tmpfs buffers and replace all references to pages in comments with folios. Partially based on a patch from Dave Chinner <dchinner@redhat.com>. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10xfs: use vmalloc instead of vm_map_area for buffer backing memoryChristoph Hellwig
The fallback buffer allocation path currently open codes a suboptimal version of vmalloc to allocate pages that are then mapped into vmalloc space. Switch to using vmalloc instead, which uses all the optimizations in the common vmalloc code, and removes the need to track the backing pages in the xfs_buf structure. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10xfs: buffer items don't straddle pages anymoreDave Chinner
Unmapped buffers don't exist anymore, so the page straddling detection and slow path code can go away now. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10xfs: kill XBF_UNMAPPEDChristoph Hellwig
Unmapped buffer access is a pain, so kill it. The switch to large folios means we rarely pay a vmap penalty for large buffers, so this functionality is largely unnecessary now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10xfs: convert buffer cache to use high order foliosChristoph Hellwig
Now that we have the buffer cache using the folio API, we can extend the use of folios to allocate high order folios for multi-page buffers rather than an array of single pages that are then vmapped into a contiguous range. This creates a new type of single folio buffers that can have arbitrary order in addition to the existing multi-folio buffers made up of many single page folios that get vmapped. The single folio is for now stashed into the existing b_pages array, but that will go away entirely later in the series and remove the temporary page vs folio typing issues that only work because the two structures currently can be used largely interchangeable. The code that allocates buffers will optimistically attempt a high order folio allocation as a fast path if the buffer size is a power of two and thus fits into a folio. If this high order allocation fails, then we fall back to the existing multi-folio allocation code. This now forms the slow allocation path, and hopefully will be largely unused in normal conditions except for buffers with size that are not a power of two like larger remote xattrs. This should improve performance of large buffer operations (e.g. large directory block sizes) as we should now mostly avoid the expense of vmapping large buffers (and the vmap lock contention that can occur) as well as avoid the runtime pressure that frequently accessing kernel vmapped pages put on the TLBs. Based on a patch from Dave Chinner <dchinner@redhat.com>, but mutilated beyond recognition. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10xfs: remove the kmalloc to page allocator fallbackChristoph Hellwig
Since commit 59bb47985c1d ("mm, sl[aou]b: guarantee natural alignment for kmalloc(power-of-two)", kmalloc and friends guarantee that power of two sized allocations are naturally aligned. Limit our use of kmalloc for buffers to these power of two sizes and remove the fallback to the page allocator for this case, but keep a check in addition to trusting the slab allocator to get the alignment right. Also refactor the kmalloc path to reuse various calculations for the size and gfp flags. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10xfs: refactor backing memory allocations for buffersChristoph Hellwig
Lift handling of shmem and slab backed buffers into xfs_buf_alloc_pages and rename the result to xfs_buf_alloc_backing_mem. This shares more code and ensures uncached buffers can also use slab, which slightly reduces the memory usage of growfs on 512 byte sector size file systems, but more importantly means the allocation invariants are the same for cached and uncached buffers. Document these new invariants with a big fat comment mostly stolen from a patch by Dave Chinner. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10xfs: remove xfs_buf_is_vmappedChristoph Hellwig
No need to look at the page count if we can simply call is_vmalloc_addr on bp->b_addr. This prepares for eventualy removing the b_page_count field. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10xfs: remove xfs_buf.b_offsetChristoph Hellwig
b_offset is only set for slab backed buffers and always set to offset_in_page(bp->b_addr), which can be done just as easily in the only user of b_offset. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10xfs: add a fast path to xfs_buf_zero when b_addr is setChristoph Hellwig
No need to walk the page list if bp->b_addr is valid. That also means b_offset doesn't need to be taken into account in the unmapped loop as b_offset is only set for kmem backed buffers which are always mapped. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10xfs: unmapped buffer item size straddling mismatchDave Chinner
We never log large contiguous regions of unmapped buffers, so this bug is never triggered by the current code. However, the slowpath for formatting buffer straddling regions is broken. That is, the size and shape of the log vector calculated across a straddle does not match how the formatting code formats a straddle. This results in a log vector with an uninitialised iovec and this causes a crash when xlog_write_full() goes to copy the iovec into the journal. Whilst touching this code, don't bother checking mapped or single folio buffers for discontiguous regions because they don't have them. This significantly reduces the overhead of this check when logging large buffers as calling xfs_buf_offset() is not free and it occurs a *lot* in those cases. Fixes: 929f8b0deb83 ("xfs: optimise xfs_buf_item_size/format for contiguous regions") Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10Merge branch 'xfs-6.15-merge' into for-nextCarlos Maiolino
XFS code for 6.15 to be merged into linux-next Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10Merge branch 'xfs-6.15-zoned_devices' into xfs-6.15-mergeCarlos Maiolino
Merge Zoned devices support for XFS Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10Merge branch 'vfs-6.15.iomap' of ↵Carlos Maiolino
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs into xfs-6.15-merge XFS code for 6.15 depends on patches within iomap. Merge them before pulling in XFS code. Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-10xfs: Use abs_diff instead of XFS_ABSDIFFMatthew Wilcox (Oracle)
We have a central definition for this function since 2023, used by a number of different parts of the kernel. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-03-06Merge patch series "iomap preliminaries for large atomic write for xfs with CoW"Christian Brauner
Bring in the iomap changes required for xfs to support large atomic write with CoW. * patches from https://lore.kernel.org/r/20250303171120.2837067-1-john.g.garry@oracle.com: iomap: Lift blocksize restriction on atomic writes iomap: Support SW-based atomic writes iomap: Rename IOMAP_ATOMIC -> IOMAP_ATOMIC_HW Link: https://lore.kernel.org/r/20250303171120.2837067-1-john.g.garry@oracle.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-06iomap: Lift blocksize restriction on atomic writesRitesh Harjani (IBM)
Filesystems like ext4 can submit writes in multiples of blocksizes. But we still can't allow the writes to be split. Hence let's check if the iomap_length() is same as iter->len or not. It is the role of the FS to ensure that a single mapping may be created for an atomic write. The FS will also continue to check size and alignment legality. Signed-off-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> jpg: Tweak commit message Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20250303171120.2837067-7-john.g.garry@oracle.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-06iomap: Support SW-based atomic writesJohn Garry
Currently atomic write support requires dedicated HW support. This imposes a restriction on the filesystem that disk blocks need to be aligned and contiguously mapped to FS blocks to issue atomic writes. XFS has no method to guarantee FS block alignment for regular, non-RT files. As such, atomic writes are currently limited to 1x FS block there. To deal with the scenario that we are issuing an atomic write over misaligned or discontiguous data blocks - and raise the atomic write size limit - support a SW-based software emulated atomic write mode. For XFS, this SW-based atomic writes would use CoW support to issue emulated untorn writes. It is the responsibility of the FS to detect discontiguous atomic writes and switch to IOMAP_DIO_ATOMIC_SW mode and retry the write. Indeed, SW-based atomic writes could be used always when the mounted bdev does not support HW offload, but this strategy is not initially expected to be used. Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20250303171120.2837067-6-john.g.garry@oracle.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-06iomap: Rename IOMAP_ATOMIC -> IOMAP_ATOMIC_HWJohn Garry
In future xfs will support a SW-based atomic write, so rename IOMAP_ATOMIC -> IOMAP_ATOMIC_HW to be clear which mode is being used. Also relocate setting of IOMAP_ATOMIC_HW to the write path in __iomap_dio_rw(), to be clear that this flag is only relevant to writes. Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20250303171120.2837067-3-john.g.garry@oracle.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-06Merge branch 'vfs-6.15.shared.iomap' of ↵Christian Brauner
gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs Bring in iomap changes that xfs relies on. Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-04Merge tag 'xfs-zoned-allocator-2025-03-03' of ↵Carlos Maiolino
git://git.infradead.org/users/hch/xfs into xfs-6.15-zoned_devices xfs: add support for zoned devices Add support for the new zoned space allocator and thus for zoned devices: https://zonedstorage.io/docs/introduction/zoned-storage to XFS. This has been developed for and tested on both SMR hard drives, which are the oldest and most common class of zoned devices: https://zonedstorage.io/docs/introduction/smr and ZNS SSDs: https://zonedstorage.io/docs/introduction/zns It has not been tested with zoned UFS devices, as their current capacity points and performance characteristics aren't too interesting for XFS use cases (but never say never). Sequential write only zones are only supported for data using a new allocator for the RT device, which maps each zone to a rtgroup which is written sequentially. All metadata and (for now) the log require using randomly writable space. This means a realtime device is required to support zoned storage, but for the common case of SMR hard drives that contain random writable zones and sequential write required zones on the same block device, the concept of an internal RT device is added which means using XFS on a SMR HDD is as simple as: $ mkfs.xfs /dev/sda $ mount /dev/sda /mnt When using NVMe ZNS SSDs that do not support conventional zones, the traditional multi-device RT configuration is required. E.g. for an SSD with a conventional namespace 1 and a zoned namespace 2: $ mkfs.xfs /dev/nvme0n1 -o rtdev=/dev/nvme0n2 $ mount -o rtdev=/dev/nvme0n2 /dev/nvme0n1 /mnt The zoned allocator can also be used on conventional block devices, or on conventional zones (e.g. when using an SMR HDD as the external RT device). For example using zoned XFS on normal SSDs shows very nice performance advantages and write amplification reduction for intelligent workloads like RocksDB. Some work is still in progress or planned, but should not affect the integration with the rest of XFS or the on-disk format: - support for quotas - support for reflinks Note that the I/O path already supports reflink, but garbage collection isn't refcount aware yet and would unshare shared blocks, thus rendering the feature useless.
2025-03-03xfs: export max_open_zones in sysfsChristoph Hellwig
Add a zoned group with an attribute for the maximum number of open zones. This allows querying the open zones for data placement tests, or also for placement aware applications that are in control of the entire file system. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: contain more sysfs code in xfs_sysfs.cChristoph Hellwig
Extend the error sysfs initialization helper to include the neighbouring attributes as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: export zone stats in /proc/*/mountstatsHans Holmberg
Add the per-zone life time hint and the used block distribution for fully written zones, grouping reclaimable zones in fixed-percentage buckets spanning 0..9%, 10..19% and full zones as 100% used as well as a few statistics about the zone allocator and open and reclaimable zones in /proc/*/mountstats. This gives good insight into data fragmentation and data placement success rate. Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com> Co-developed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: wire up the show_stats super operationChristoph Hellwig
The show_stats option allows a file system to dump plain text statistic on a per-mount basis into /proc/*/mountstats. Wire up a no-op version which will grow useful information for zoned file systems later. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: support write life time based data placementHans Holmberg
Add a file write life time data placement allocation scheme that aims to minimize fragmentation and thereby to do two things: a) separate file data to different zones when possible. b) colocate file data of similar life times when feasible. To get best results, average file sizes should align with the zone capacity that is reported through the XFS_IOC_FSGEOMETRY ioctl. This improvement in data placement efficiency reduces the number of blocks requiring relocation by GC, and thus decreases overall write amplification. The impact on performance varies depending on how full the file system is. For RocksDB using leveled compaction, the lifetime hints can improve throughput for overwrite workloads at 80% file system utilization by ~10%, but for lower file system utilization there won't be as much benefit in application performance as there is less need for garbage collection to start with. Lifetime hints can be disabled using the nolifetime mount option. Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: add a max_open_zones mount optionChristoph Hellwig
Allow limiting the number of open zones used below that exported by the device. This is required to tune the number of write streams when zoned RT devices are used on conventional devices, and can be useful on zoned devices that support a very large number of open zones. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: support zone gapsChristoph Hellwig
Zoned devices can have gaps beyond the usable capacity of a zone and the end in the LBA/daddr address space. In other words, the hardware equivalent to the RT groups already takes care of the power of 2 alignment for us. In this case the sparse FSB/RTB address space maps 1:1 to the device address space. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: enable the zoned RT device featureChristoph Hellwig
Enable the zoned RT device directory feature. With this feature, RT groups are written sequentially and always emptied before rewriting the blocks. This perfectly maps to zoned devices, but can also be used on conventional block devices. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: disable rt quotas for zoned file systemsChristoph Hellwig
They'll need a little more work. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: disable reflink for zoned file systemsChristoph Hellwig
While the zoned on-disk format supports reflinks, the GC code currently always unshares reflinks when moving blocks to new zones, thus making the feature unusuable. Disable reflinks until the GC code is refcount aware. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: enable fsmap reporting for internal RT devicesChristoph Hellwig
File system with internal RT devices are a bit odd in that we need to report AGs and RGs. To make this happen use separate synthetic fmr_device values for the different sections instead of the dev_t mapping used by other XFS configurations. The data device is reported as file system metadata before the start of the RGs for the synthetic RT fmr_device. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: support xrep_require_rtext_inuse on zoned file systemsChristoph Hellwig
Space usage is tracked by the rmap, which already is separately cross-referenced. But on top of that we have the write pointer and can do a basic sanity check here that the block is not beyond the write pointer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: support xchk_xref_is_used_rt_space on zoned file systemsChristoph Hellwig
Space usage is tracked by the rmap, which already is separately cross-referenced. But on top of that we have the write pointer and can do a basic sanity check here that the block is not beyond the write pointer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: allow COW forks on zoned file systems in xchk_bmapChristoph Hellwig
Zoned file systems can have COW forks even without reflinks. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: support growfs on zoned file systemsChristoph Hellwig
Replace the inner loop growing one RT bitmap block at a time with one just modifying the superblock counters for growing an entire zone (aka RTG). The big restriction is just like at mkfs time only a RT extent size of a single FSB is allowed, and the file system capacity needs to be aligned to the zone size. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: hide reserved RT blocks from statfsChristoph Hellwig
File systems with a zoned RT device have a large number of reserved blocks that are required for garbage collection, and which can't be filled with user data. Exclude them from the available blocks reported through stat(v)fs. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: wire up zoned block freeing in xfs_rtextent_free_finish_itemChristoph Hellwig
Make xfs_rtextent_free_finish_item call into the zoned allocator to free blocks on zoned RT devices. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: implement direct writes to zoned RT devicesChristoph Hellwig
Direct writes to zoned RT devices are extremely simple. After taking the block reservation before acquiring the iolock, the iomap direct I/O calls into ->iomap_begin which will return a "fake" iomap for the entire requested range. The actual block allocation is then done from the submit_io handler using code shared with the buffered I/O path. The iomap_dio_ops set the bio_set to the (iomap) ioend one and initialize the embedded ioend, which allows reusing the existing ioend based buffered I/O completion path. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: implement buffered writes to zoned RT devicesChristoph Hellwig
Implement buffered writes including page faults and block zeroing for zoned RT devices. Buffered writes to zoned RT devices are split into three phases: 1) a reservation for the worst case data block usage is taken before acquiring the iolock. When there are enough free blocks but not enough available one, garbage collection is kicked off to free the space before continuing with the write. If there isn't enough freeable space, the block reservation is reduced and a short write will happen as expected by normal Linux write semantics. 2) with the iolock held, the generic iomap buffered write code is called, which through the iomap_begin operation usually just inserts delalloc extents for the range in a single iteration. Only for overwrites of existing data that are not block aligned, or zeroing operations the existing extent mapping is read to fill out the srcmap and to figure out if zeroing is required. 3) the ->map_blocks callback to the generic iomap writeback code calls into the zoned space allocator to actually allocate on-disk space for the range before kicking of the writeback. Note that because all writes are out of place, truncate or hole punches that are not aligned to block size boundaries need to allocate space. For block zeroing from truncate, ->setattr is called with the iolock (aka i_rwsem) already held, so a hacky deviation from the above scheme is needed. In this case the space reservations is called with the iolock held, but is required not to block and can dip into the reserved block pool. This can lead to -ENOSPC when truncating a file, which is unfortunate. But fixing the calling conventions in the VFS is probably much easier with code requiring it already in mainline. Similarly because all writes are out place, the zoned allocator can't support unwritten extents and thus the FALLOC_FL_ALLOCATE_RANGE range mode of fallocate. Other fallocate modes that would reserved space but don't need to to provide proper semantics do work but do not reserve space. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: implement zoned garbage collectionChristoph Hellwig
RT groups on a zoned file system need to be completely empty before their space can be reused. This means that partially empty groups need to be emptied entirely to free up space if no entirely free groups are available. Add a garbage collection thread that moves all data out of the least used zone when not enough free zones are available, and which resets all zones that have been emptied. To find empty zone a simple set of 10 buckets based on the amount of space used in the zone is used. To empty zones, the rmap is walked to find the owners and the data is read and then written to the new place. To automatically defragment files the rmap records are sorted by inode and logical offset. This means defragmentation of parallel writes into a single zone happens automatically when performing garbage collection. Because holding the iolock over the entire GC cycle would inject very noticeable latency for other accesses to the inodes, the iolock is not taken while performing I/O. Instead the I/O completion handler checks that the mapping hasn't changed over the one recorded at the start of the GC cycle and doesn't update the mapping if it change. Co-developed-by: Hans Holmberg <hans.holmberg@wdc.com> Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: add support for zoned space reservationsChristoph Hellwig
For zoned file systems garbage collection (GC) has to take the iolock and mmaplock after moving data to a new place to synchronize with readers. This means waiting for garbage collection with the iolock can deadlock. To avoid this, the worst case required blocks have to be reserved before taking the iolock, which is done using a new RTAVAILABLE counter that tracks blocks that are free to write into and don't require garbage collection. The new helpers try to take these available blocks, and if there aren't enough available it wakes and waits for GC. This is done using a list of on-stack reservations to ensure fairness. Co-developed-by: Hans Holmberg <hans.holmberg@wdc.com> Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: add the zoned space allocatorChristoph Hellwig
For zoned RT devices space is always allocated at the write pointer, that is right after the last written block and only recorded on I/O completion. Because the actual allocation algorithm is very simple and just involves picking a good zone - preferably the one used for the last write to the inode. As the number of zones that can written at the same time is usually limited by the hardware, selecting a zone is done as late as possible from the iomap dio and buffered writeback bio submissions helpers just before submitting the bio. Given that the writers already took a reservation before acquiring the iolock, space will always be readily available if an open zone slot is available. A new structure is used to track these open zones, and pointed to by the xfs_rtgroup. Because zoned file systems don't have a rsum cache the space for that pointer can be reused. Allocations are only recorded at I/O completion time. The scheme used for that is very similar to the reflink COW end I/O path. Co-developed-by: Hans Holmberg <hans.holmberg@wdc.com> Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: parse and validate hardware zone informationChristoph Hellwig
Add support to validate and parse reported hardware zone state. Co-developed-by: Hans Holmberg <hans.holmberg@wdc.com> Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: skip zoned RT inodes in xfs_inodegc_want_queue_rt_fileChristoph Hellwig
The zoned allocator never performs speculative preallocations, so don't bother queueing up zoned inodes here. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: don't call xfs_can_free_eofblocks from ->release for zoned inodesChristoph Hellwig
Zoned file systems require out of place writes and thus can't support post-EOF speculative preallocations. Avoid the pointless ilock critical section to find out that none can be freed. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: disable FITRIM for zoned RT devicesChristoph Hellwig
The zoned allocator unconditionally issues zone resets or discards after emptying an entire zone, so supporting FITRIM for a zoned RT device is not useful. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: disable sb_frextents for zoned file systemsChristoph Hellwig
Zoned file systems not only don't use the global frextents counter, but for them the in-memory percpu counter also includes reservations taken before even allocating delalloc extent records, so it will never match the per-zone used information. Disable all updates and verification of the sb counter for zoned file systems as it isn't useful for them. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: export zoned geometry via XFS_FSOP_GEOMChristoph Hellwig
Export the zoned geometry information so that userspace can query it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
2025-03-03xfs: allow internal RT devices for zoned modeChristoph Hellwig
Allow creating an RT subvolume on the same device as the main data device. This is mostly used for SMR HDDs where the conventional zones are used for the data device and the sequential write required zones for the zoned RT section. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>