From 98321b5139f92a736a426404fb6e23bfb8feb9cc Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Sun, 15 Jan 2023 08:49:04 -0800 Subject: [PATCH] iomap: Add iomap_get_folio helper Add an iomap_get_folio() helper that gets a folio reference based on an iomap iterator and an offset into the address space. Use it in iomap_write_begin(). Signed-off-by: Andreas Gruenbacher Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Darrick J. Wong --- fs/iomap/buffered-io.c | 39 ++++++++++++++++++++++++++++++--------- include/linux/iomap.h | 1 + 2 files changed, 31 insertions(+), 9 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index d4b444e..de4a8e5 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -457,6 +457,33 @@ bool iomap_is_partially_uptodate(struct folio *folio, size_t from, size_t count) } EXPORT_SYMBOL_GPL(iomap_is_partially_uptodate); +/** + * iomap_get_folio - get a folio reference for writing + * @iter: iteration structure + * @pos: start offset of write + * + * Returns a locked reference to the folio at @pos, or an error pointer if the + * folio could not be obtained. + */ +struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos) +{ + unsigned fgp = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE | FGP_NOFS; + struct folio *folio; + + if (iter->flags & IOMAP_NOWAIT) + fgp |= FGP_NOWAIT; + + folio = __filemap_get_folio(iter->inode->i_mapping, pos >> PAGE_SHIFT, + fgp, mapping_gfp_mask(iter->inode->i_mapping)); + if (folio) + return folio; + + if (iter->flags & IOMAP_NOWAIT) + return ERR_PTR(-EAGAIN); + return ERR_PTR(-ENOMEM); +} +EXPORT_SYMBOL_GPL(iomap_get_folio); + bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags) { trace_iomap_release_folio(folio->mapping->host, folio_pos(folio), @@ -603,12 +630,8 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos, const struct iomap_page_ops *page_ops = iter->iomap.page_ops; const struct iomap *srcmap = iomap_iter_srcmap(iter); struct folio *folio; - unsigned fgp = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE | FGP_NOFS; int status = 0; - if (iter->flags & IOMAP_NOWAIT) - fgp |= FGP_NOWAIT; - BUG_ON(pos + len > iter->iomap.offset + iter->iomap.length); if (srcmap != &iter->iomap) BUG_ON(pos + len > srcmap->offset + srcmap->length); @@ -625,12 +648,10 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos, return status; } - folio = __filemap_get_folio(iter->inode->i_mapping, pos >> PAGE_SHIFT, - fgp, mapping_gfp_mask(iter->inode->i_mapping)); - if (!folio) { - status = (iter->flags & IOMAP_NOWAIT) ? -EAGAIN : -ENOMEM; + folio = iomap_get_folio(iter, pos); + if (IS_ERR(folio)) { __iomap_put_folio(iter, pos, 0, NULL); - return status; + return PTR_ERR(folio); } /* diff --git a/include/linux/iomap.h b/include/linux/iomap.h index ecf815b..188d14e 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -261,6 +261,7 @@ int iomap_file_buffered_write_punch_delalloc(struct inode *inode, int iomap_read_folio(struct folio *folio, const struct iomap_ops *ops); void iomap_readahead(struct readahead_control *, const struct iomap_ops *ops); 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); bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags); void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len); int iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len, -- 2.7.4