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| author | Christoph Hellwig <hch@lst.de> | 2025-07-10 15:33:37 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-07-14 10:51:33 +0200 |
| commit | c5690dd0197809bc5305f474a71b2e71e7eac0ff (patch) | |
| tree | 42f77dbe9978cb2047dca9dc3c2f982a54a8b9cf | |
| parent | iomap: improve argument passing to iomap_read_folio_sync (diff) | |
| download | linux-c5690dd0197809bc5305f474a71b2e71e7eac0ff.tar.gz linux-c5690dd0197809bc5305f474a71b2e71e7eac0ff.zip | |
iomap: add read_folio_range() handler for buffered writes
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 <joannelkoong@gmail.com>
[hch: renamed to read_folio_range, pass less arguments]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/20250710133343.399917-14-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
| -rw-r--r-- | Documentation/filesystems/iomap/operations.rst | 6 | ||||
| -rw-r--r-- | fs/iomap/buffered-io.c | 13 | ||||
| -rw-r--r-- | include/linux/iomap.h | 10 |
3 files changed, 25 insertions, 4 deletions
diff --git a/Documentation/filesystems/iomap/operations.rst b/Documentation/filesystems/iomap/operations.rst index a9b48ce4af92..067ed8e14ef3 100644 --- a/Documentation/filesystems/iomap/operations.rst +++ b/Documentation/filesystems/iomap/operations.rst @@ -68,6 +68,8 @@ The following address space operations can be wrapped easily: void (*put_folio)(struct inode *inode, loff_t pos, unsigned copied, struct folio *folio); bool (*iomap_valid)(struct inode *inode, const struct iomap *iomap); + int (*read_folio_range)(const struct iomap_iter *iter, + struct folio *folio, loff_t pos, size_t len); }; iomap calls these functions: @@ -123,6 +125,10 @@ iomap calls these functions: ``->iomap_valid``, then the iomap should considered stale and the validation failed. + - ``read_folio_range``: Called to synchronously read in the range that will + be written to. If this function is not provided, iomap will default to + submitting a bio read request. + These ``struct kiocb`` flags are significant for buffered I/O with iomap: * ``IOCB_NOWAIT``: Turns on ``IOMAP_NOWAIT``. diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 8a44f56a3a80..aed4fc30a849 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -671,7 +671,8 @@ static int iomap_read_folio_range(const struct iomap_iter *iter, return submit_bio_wait(&bio); } -static int __iomap_write_begin(const struct iomap_iter *iter, size_t len, +static int __iomap_write_begin(const struct iomap_iter *iter, + const struct iomap_write_ops *write_ops, size_t len, struct folio *folio) { struct iomap_folio_state *ifs; @@ -722,8 +723,12 @@ static int __iomap_write_begin(const struct iomap_iter *iter, size_t len, if (iter->flags & IOMAP_NOWAIT) return -EAGAIN; - status = iomap_read_folio_range(iter, folio, - block_start, plen); + if (write_ops && write_ops->read_folio_range) + status = write_ops->read_folio_range(iter, + folio, block_start, plen); + else + status = iomap_read_folio_range(iter, + folio, block_start, plen); if (status) return status; } @@ -839,7 +844,7 @@ static int iomap_write_begin(struct iomap_iter *iter, else if (srcmap->flags & IOMAP_F_BUFFER_HEAD) status = __block_write_begin_int(folio, pos, len, NULL, srcmap); else - status = __iomap_write_begin(iter, len, folio); + status = __iomap_write_begin(iter, write_ops, len, folio); if (unlikely(status)) goto out_unlock; diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 80f543cc4fe8..73dceabc21c8 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -166,6 +166,16 @@ struct iomap_write_ops { * locked by the iomap code. */ bool (*iomap_valid)(struct inode *inode, const struct iomap *iomap); + + /* + * Optional if the filesystem wishes to provide a custom handler for + * reading in the contents of a folio, otherwise iomap will default to + * submitting a bio read request. + * + * The read must be done synchronously. + */ + int (*read_folio_range)(const struct iomap_iter *iter, + struct folio *folio, loff_t pos, size_t len); }; /* |