From 6d840a18773f36baaecc2d2f7fb18ec5862349e6 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Thu, 9 Nov 2023 21:06:02 +0000 Subject: buffer: return bool from grow_dev_folio() Patch series "More buffer_head cleanups", v2. The first patch is a left-over from last cycle. The rest fix "obvious" block size > PAGE_SIZE problems. I haven't tested with a large block size setup (but I have done an ext4 xfstests run). This patch (of 7): Rename grow_dev_page() to grow_dev_folio() and make it return a bool. Document what that bool means; it's more subtle than it first appears. Also rename the 'failed' label to 'unlock' beacuse it's not exactly 'failed'. It just hasn't succeeded. Link: https://lkml.kernel.org/r/20231109210608.2252323-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Cc: Hannes Reinecke Cc: Luis Chamberlain Cc: Pankaj Raghav Cc: Ryusuke Konishi Signed-off-by: Andrew Morton --- fs/buffer.c | 50 +++++++++++++++++++++++++------------------------- 1 file changed, 25 insertions(+), 25 deletions(-) (limited to 'fs') diff --git a/fs/buffer.c b/fs/buffer.c index 967f34b70aa8..8dad6c691e14 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1024,40 +1024,43 @@ static sector_t folio_init_buffers(struct folio *folio, } /* - * Create the page-cache page that contains the requested block. + * Create the page-cache folio that contains the requested block. * * This is used purely for blockdev mappings. + * + * Returns false if we have a 'permanent' failure. Returns true if + * we succeeded, or the caller should retry. */ -static int -grow_dev_page(struct block_device *bdev, sector_t block, - pgoff_t index, int size, int sizebits, gfp_t gfp) +static bool grow_dev_folio(struct block_device *bdev, sector_t block, + pgoff_t index, unsigned size, int sizebits, gfp_t gfp) { struct inode *inode = bdev->bd_inode; struct folio *folio; struct buffer_head *bh; - sector_t end_block; - int ret = 0; + sector_t end_block = 0; folio = __filemap_get_folio(inode->i_mapping, index, FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp); if (IS_ERR(folio)) - return PTR_ERR(folio); + return false; bh = folio_buffers(folio); if (bh) { if (bh->b_size == size) { end_block = folio_init_buffers(folio, bdev, (sector_t)index << sizebits, size); - goto done; + goto unlock; } + + /* Caller should retry if this call fails */ + end_block = ~0ULL; if (!try_to_free_buffers(folio)) - goto failed; + goto unlock; } - ret = -ENOMEM; bh = folio_alloc_buffers(folio, size, gfp | __GFP_ACCOUNT); if (!bh) - goto failed; + goto unlock; /* * Link the folio to the buffers and initialise them. Take the @@ -1069,20 +1072,19 @@ grow_dev_page(struct block_device *bdev, sector_t block, end_block = folio_init_buffers(folio, bdev, (sector_t)index << sizebits, size); spin_unlock(&inode->i_mapping->private_lock); -done: - ret = (block < end_block) ? 1 : -ENXIO; -failed: +unlock: folio_unlock(folio); folio_put(folio); - return ret; + return block < end_block; } /* - * Create buffers for the specified block device block's page. If - * that page was dirty, the buffers are set dirty also. + * Create buffers for the specified block device block's folio. If + * that folio was dirty, the buffers are set dirty also. Returns false + * if we've hit a permanent error. */ -static int -grow_buffers(struct block_device *bdev, sector_t block, int size, gfp_t gfp) +static bool grow_buffers(struct block_device *bdev, sector_t block, + unsigned size, gfp_t gfp) { pgoff_t index; int sizebits; @@ -1099,11 +1101,11 @@ grow_buffers(struct block_device *bdev, sector_t block, int size, gfp_t gfp) "device %pg\n", __func__, (unsigned long long)block, bdev); - return -EIO; + return false; } - /* Create a page with the proper size buffers.. */ - return grow_dev_page(bdev, block, index, size, sizebits, gfp); + /* Create a folio with the proper size buffers */ + return grow_dev_folio(bdev, block, index, size, sizebits, gfp); } static struct buffer_head * @@ -1124,14 +1126,12 @@ __getblk_slow(struct block_device *bdev, sector_t block, for (;;) { struct buffer_head *bh; - int ret; bh = __find_get_block(bdev, block, size); if (bh) return bh; - ret = grow_buffers(bdev, block, size, gfp); - if (ret < 0) + if (!grow_buffers(bdev, block, size, gfp)) return NULL; } } -- cgit v1.2.3