It's useful to get filesystem-specific information using the
existing private field in the @iomap_iter passed to iomap_{begin,end}
for advanced usage for iomap buffered reads, which is much like the
current iomap DIO.For example, EROFS needs it to: - implement an efficient page cache sharing feature, since iomap needs to apply to anon inode page cache but we'd like to get the backing inode/fs instead, so filesystem-specific private data is needed to keep such information; - pass in both struct page * and void * for inline data to avoid kmap_to_page() usage (which is bogus). Reviewed-by: Gao Xiang <[email protected]> Signed-off-by: Hongbo Li <[email protected]> --- fs/fuse/file.c | 4 ++-- fs/iomap/buffered-io.c | 6 ++++-- include/linux/iomap.h | 8 ++++---- 3 files changed, 10 insertions(+), 8 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 01bc894e9c2b..f5d8887c1922 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -979,7 +979,7 @@ static int fuse_read_folio(struct file *file, struct folio *folio) return -EIO; } - iomap_read_folio(&fuse_iomap_ops, &ctx); + iomap_read_folio(&fuse_iomap_ops, &ctx, NULL); fuse_invalidate_atime(inode); return 0; } @@ -1081,7 +1081,7 @@ static void fuse_readahead(struct readahead_control *rac) if (fuse_is_bad(inode)) return; - iomap_readahead(&fuse_iomap_ops, &ctx); + iomap_readahead(&fuse_iomap_ops, &ctx, NULL); } static ssize_t fuse_cache_read_iter(struct kiocb *iocb, struct iov_iter *to) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index e5c1ca440d93..5f7dcbabbda3 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -555,13 +555,14 @@ static int iomap_read_folio_iter(struct iomap_iter *iter, } void iomap_read_folio(const struct iomap_ops *ops, - struct iomap_read_folio_ctx *ctx) + struct iomap_read_folio_ctx *ctx, void *private) { struct folio *folio = ctx->cur_folio; struct iomap_iter iter = { .inode = folio->mapping->host, .pos = folio_pos(folio), .len = folio_size(folio), + .private = private, }; size_t bytes_submitted = 0; int ret; @@ -620,13 +621,14 @@ static int iomap_readahead_iter(struct iomap_iter *iter, * the filesystem to be reentered. */ void iomap_readahead(const struct iomap_ops *ops, - struct iomap_read_folio_ctx *ctx) + struct iomap_read_folio_ctx *ctx, void *private) { struct readahead_control *rac = ctx->rac; struct iomap_iter iter = { .inode = rac->mapping->host, .pos = readahead_pos(rac), .len = readahead_length(rac), + .private = private, }; size_t cur_bytes_submitted; diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 520e967cb501..441d614e9fdf 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -341,9 +341,9 @@ ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, const struct iomap_ops *ops, const struct iomap_write_ops *write_ops, void *private); void iomap_read_folio(const struct iomap_ops *ops, - struct iomap_read_folio_ctx *ctx); + struct iomap_read_folio_ctx *ctx, void *private); void iomap_readahead(const struct iomap_ops *ops, - struct iomap_read_folio_ctx *ctx); + struct iomap_read_folio_ctx *ctx, void *private); bool iomap_is_partially_uptodate(struct folio *, size_t from, size_t count); struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos, size_t len); bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags); @@ -595,7 +595,7 @@ static inline void iomap_bio_read_folio(struct folio *folio, .cur_folio = folio, }; - iomap_read_folio(ops, &ctx); + iomap_read_folio(ops, &ctx, NULL); } static inline void iomap_bio_readahead(struct readahead_control *rac, @@ -606,7 +606,7 @@ static inline void iomap_bio_readahead(struct readahead_control *rac, .rac = rac, }; - iomap_readahead(ops, &ctx); + iomap_readahead(ops, &ctx, NULL); } #endif /* CONFIG_BLOCK */ -- 2.22.0
