From 640ab98fb3629c0f8417b9b2532eca596495f3bb Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 27 Sep 2017 05:40:16 -0600 Subject: buffer: have alloc_page_buffers() use __GFP_NOFAIL Instead of adding weird retry logic in that function, utilize __GFP_NOFAIL to ensure that the vm takes care of handling any potential retries appropriately. This means we don't have to call free_more_memory() from here. Reviewed-by: Nikolay Borisov Reviewed-by: Jan Kara Signed-off-by: Jens Axboe --- fs/buffer.c | 33 ++++++++++----------------------- 1 file changed, 10 insertions(+), 23 deletions(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index 170df856bdb9..1234ae343aef 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -861,16 +861,19 @@ int remove_inode_buffers(struct inode *inode) * which may not fail from ordinary buffer allocations. */ struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, - int retry) + bool retry) { struct buffer_head *bh, *head; + gfp_t gfp = GFP_NOFS; long offset; -try_again: + if (retry) + gfp |= __GFP_NOFAIL; + head = NULL; offset = PAGE_SIZE; while ((offset -= size) >= 0) { - bh = alloc_buffer_head(GFP_NOFS); + bh = alloc_buffer_head(gfp); if (!bh) goto no_grow; @@ -896,23 +899,7 @@ no_grow: } while (head); } - /* - * Return failure for non-async IO requests. Async IO requests - * are not allowed to fail, so we have to wait until buffer heads - * become available. But we don't want tasks sleeping with - * partially complete buffers, so all were released above. - */ - if (!retry) - return NULL; - - /* We're _really_ low on memory. Now we just - * wait for old buffer heads to become free due to - * finishing IO. Since this is an async request and - * the reserve list is empty, we're sure there are - * async buffer heads in use. - */ - free_more_memory(); - goto try_again; + return NULL; } EXPORT_SYMBOL_GPL(alloc_page_buffers); @@ -1021,7 +1008,7 @@ grow_dev_page(struct block_device *bdev, sector_t block, /* * Allocate some buffers for this page */ - bh = alloc_page_buffers(page, size, 0); + bh = alloc_page_buffers(page, size, false); if (!bh) goto failed; @@ -1575,7 +1562,7 @@ void create_empty_buffers(struct page *page, { struct buffer_head *bh, *head, *tail; - head = alloc_page_buffers(page, blocksize, 1); + head = alloc_page_buffers(page, blocksize, true); bh = head; do { bh->b_state |= b_state; @@ -2638,7 +2625,7 @@ int nobh_write_begin(struct address_space *mapping, * Be careful: the buffer linked list is a NULL terminated one, rather * than the circular one we're used to. */ - head = alloc_page_buffers(page, blocksize, 0); + head = alloc_page_buffers(page, blocksize, false); if (!head) { ret = -ENOMEM; goto out_release; -- cgit v1.2.3