kernel/linux.git/include/linux/iomap.h, branch v6.18.21

iomap: add read_folio_range() handler for buffered writes

2025-07-14T08:51:33+00:00

Add a read_folio_range() handler for buffered writes that filesystems may pass in if they wish to provide a custom handler for synchronously reading in the contents of a folio. Signed-off-by: Joanne Koong [hch: renamed to read_folio_range, pass less arguments] Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/20250710133343.399917-14-hch@lst.de Reviewed-by: Darrick J. Wong Signed-off-by: Christian Brauner

iomap: replace iomap_folio_ops with iomap_write_ops

2025-07-14T08:51:33+00:00

The iomap_folio_ops are only used for buffered writes, including the zero and unshare variants. Rename them to iomap_write_ops to better describe the usage, and pass them through the call chain like the other operation specific methods instead of through the iomap. xfs_iomap_valid grows a IOMAP_HOLE check to keep the existing behavior that never attached the folio_ops to a iomap representing a hole. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/20250710133343.399917-12-hch@lst.de Acked-by: Damien Le Moal Reviewed-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Christian Brauner

iomap: export iomap_writeback_folio

2025-07-14T08:51:32+00:00

Allow fuse to use iomap_writeback_folio for folio laundering. Note that the caller needs to manually submit the pending writeback context. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/20250710133343.399917-11-hch@lst.de Reviewed-by: Joanne Koong Reviewed-by: Darrick J. Wong Signed-off-by: Christian Brauner

iomap: add public helpers for uptodate state manipulation

2025-07-14T08:51:32+00:00

Add a new iomap_start_folio_write helper to abstract away the write_bytes_pending handling, and export it and the existing iomap_finish_folio_write for non-iomap writeback in fuse. Signed-off-by: Joanne Koong [hch: split from a larger patch] Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/20250710133343.399917-7-hch@lst.de Reviewed-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Christian Brauner

iomap: hide ioends from the generic writeback code

2025-07-14T08:51:31+00:00

Replace the ioend pointer in iomap_writeback_ctx with a void *wb_ctx one to facilitate non-block, non-ioend writeback for use. Rename the submit_ioend method to writeback_submit and make it mandatory so that the generic writeback code stops seeing ioends and bios. Co-developed-by: Joanne Koong Signed-off-by: Joanne Koong Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/20250710133343.399917-6-hch@lst.de Acked-by: Damien Le Moal Reviewed-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Christian Brauner

iomap: refactor the writeback interface

2025-07-14T08:51:31+00:00

Replace ->map_blocks with a new ->writeback_range, which differs in the following ways: - it must also queue up the I/O for writeback, that is called into the slightly refactored and extended in scope iomap_add_to_ioend for each region - can handle only a part of the requested region, that is the retry loop for partial mappings moves to the caller - handles cleanup on failures as well, and thus also replaces the discard_folio method only implemented by XFS. This will allow to use the iomap writeback code also for file systems that are not block based like fuse. Co-developed-by: Joanne Koong Signed-off-by: Joanne Koong Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/20250710133343.399917-5-hch@lst.de Acked-by: Damien Le Moal # zonefs Reviewed-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Christian Brauner

iomap: pass more arguments using the iomap writeback context

2025-07-14T08:51:31+00:00

Add inode and wpc fields to pass the inode and writeback context that are needed in the entire writeback call chain, and let the callers initialize all fields in the writeback context before calling iomap_writepages to simplify the argument passing. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/20250710133343.399917-3-hch@lst.de Reviewed-by: Brian Foster Reviewed-by: Joanne Koong Reviewed-by: Johannes Thumshirn Reviewed-by: Darrick J. Wong Signed-off-by: Christian Brauner

iomap: don't lose folio dropbehind state for overwrites

2025-05-28T07:26:07+00:00

DONTCACHE I/O must have the completion punted to a workqueue, just like what is done for unwritten extents, as the completion needs task context to perform the invalidation of the folio(s). However, if writeback is started off filemap_fdatawrite_range() off generic_sync() and it's an overwrite, then the DONTCACHE marking gets lost as iomap_add_to_ioend() don't look at the folio being added and no further state is passed down to help it know that this is a dropbehind/DONTCACHE write. Check if the folio being added is marked as dropbehind, and set IOMAP_IOEND_DONTCACHE if that is the case. Then XFS can factor this into the decision making of completion context in xfs_submit_ioend(). Additionally include this ioend flag in the NOMERGE flags, to avoid mixing it with unrelated IO. Since this is the 3rd flag that will cause XFS to punt the completion to a workqueue, add a helper so that each one of them can get appropriately commented. This fixes extra page cache being instantiated when the write performed is an overwrite, rather than newly instantiated blocks. Fixes: b2cd5ae693a3 ("iomap: make buffered writes work with RWF_DONTCACHE") Signed-off-by: Jens Axboe Link: https://lore.kernel.org/5153f6e8-274d-4546-bf55-30a5018e0d03@kernel.dk Reviewed-by: Dave Chinner Signed-off-by: Christian Brauner

iomap: Fix conflicting values of iomap flags

2025-03-28T09:45:00+00:00

IOMAP_F_ATOMIC_BIO mistakenly took the same value as of IOMAP_F_SIZE_CHANGED in patch '370a6de7651b ("iomap: rework IOMAP atomic flags")'. Let's fix this and let's also create some more space for filesystem reported flags to avoid this in future. This patch makes the core iomap flags to start from bit 15, moving downwards. Note that "flags" member within struct iomap is of type u16. Fixes: 370a6de7651b ("iomap: rework IOMAP atomic flags") Signed-off-by: "Ritesh Harjani (IBM)" Link: https://lore.kernel.org/r/20250327170119.61045-1-ritesh.list@gmail.com Reviewed-by: John Garry Signed-off-by: Christian Brauner

iomap: rework IOMAP atomic flags

2025-03-20T14:16:03+00:00

Flag IOMAP_ATOMIC_SW is not really required. The idea of having this flag is that the FS ->iomap_begin callback could check if this flag is set to decide whether to do a SW (FS-based) atomic write. But the FS can set which ->iomap_begin callback it wants when deciding to do a FS-based atomic write. Furthermore, it was thought that IOMAP_ATOMIC_HW is not a proper name, as the block driver can use SW-methods to emulate an atomic write. So change back to IOMAP_ATOMIC. The ->iomap_begin callback needs though to indicate to iomap core that REQ_ATOMIC needs to be set, so add IOMAP_F_ATOMIC_BIO for that. These changes were suggested by Christoph Hellwig and Dave Chinner. Signed-off-by: John Garry Link: https://lore.kernel.org/r/20250320120250.4087011-4-john.g.garry@oracle.com Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner