From 81ee8e52a71c712dbe04994f1430cb4c88b87ad6 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Mon, 21 Sep 2020 08:58:42 -0700 Subject: [PATCH] iomap: Change calling convention for zeroing Pass the full length to iomap_zero() and dax_iomap_zero(), and have them return how many bytes they actually handled. This is preparatory work for handling THP, although it looks like DAX could actually take advantage of it if there's a larger contiguous area. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/dax.c | 13 ++++++------- fs/iomap/buffered-io.c | 33 +++++++++++++++------------------ include/linux/dax.h | 3 +-- 3 files changed, 22 insertions(+), 27 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 994ab66a9907..6ad346352a8c 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1037,18 +1037,18 @@ static vm_fault_t dax_load_hole(struct xa_state *xas, return ret; } -int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size, - struct iomap *iomap) +s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap) { sector_t sector = iomap_sector(iomap, pos & PAGE_MASK); pgoff_t pgoff; long rc, id; void *kaddr; bool page_aligned = false; - + unsigned offset = offset_in_page(pos); + unsigned size = min_t(u64, PAGE_SIZE - offset, length); if (IS_ALIGNED(sector << SECTOR_SHIFT, PAGE_SIZE) && - IS_ALIGNED(size, PAGE_SIZE)) + (size == PAGE_SIZE)) page_aligned = true; rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff); @@ -1058,8 +1058,7 @@ int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size, id = dax_read_lock(); if (page_aligned) - rc = dax_zero_page_range(iomap->dax_dev, pgoff, - size >> PAGE_SHIFT); + rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1); else rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL); if (rc < 0) { @@ -1072,7 +1071,7 @@ int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size, dax_flush(iomap->dax_dev, kaddr + offset, size); } dax_read_unlock(id); - return 0; + return size; } static loff_t diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index f26b24f39de4..8b6cca7e34e4 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -898,11 +898,13 @@ iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len, } EXPORT_SYMBOL_GPL(iomap_file_unshare); -static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset, - unsigned bytes, struct iomap *iomap, struct iomap *srcmap) +static s64 iomap_zero(struct inode *inode, loff_t pos, u64 length, + struct iomap *iomap, struct iomap *srcmap) { struct page *page; int status; + unsigned offset = offset_in_page(pos); + unsigned bytes = min_t(u64, PAGE_SIZE - offset, length); status = iomap_write_begin(inode, pos, bytes, 0, &page, iomap, srcmap); if (status) @@ -914,38 +916,33 @@ static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset, return iomap_write_end(inode, pos, bytes, bytes, page, iomap, srcmap); } -static loff_t -iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count, - void *data, struct iomap *iomap, struct iomap *srcmap) +static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos, + loff_t length, void *data, struct iomap *iomap, + struct iomap *srcmap) { bool *did_zero = data; loff_t written = 0; - int status; /* already zeroed? we're done. */ if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN) - return count; + return length; do { - unsigned offset, bytes; - - offset = offset_in_page(pos); - bytes = min_t(loff_t, PAGE_SIZE - offset, count); + s64 bytes; if (IS_DAX(inode)) - status = dax_iomap_zero(pos, offset, bytes, iomap); + bytes = dax_iomap_zero(pos, length, iomap); else - status = iomap_zero(inode, pos, offset, bytes, iomap, - srcmap); - if (status < 0) - return status; + bytes = iomap_zero(inode, pos, length, iomap, srcmap); + if (bytes < 0) + return bytes; pos += bytes; - count -= bytes; + length -= bytes; written += bytes; if (did_zero) *did_zero = true; - } while (count > 0); + } while (length > 0); return written; } diff --git a/include/linux/dax.h b/include/linux/dax.h index 6904d4e0b2e0..951a851a0481 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -214,8 +214,7 @@ vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf, int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index); int dax_invalidate_mapping_entry_sync(struct address_space *mapping, pgoff_t index); -int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size, - struct iomap *iomap); +s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap); static inline bool dax_mapping(struct address_space *mapping) { return mapping->host && IS_DAX(mapping->host);