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buffer: return bool from grow_dev_folio()

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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) <willy@infradead.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2023-11-09 21:06:02 +00:00 • committed by Andrew Morton
parent ffda655682
commit 6d840a1877
1 changed files with 25 additions and 25 deletions
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50
fs/buffer.c
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@ -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. * 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 static bool grow_dev_folio(struct block_device *bdev, sector_t block,
grow_dev_page(struct block_device *bdev, sector_t block, pgoff_t index, unsigned size, int sizebits, gfp_t gfp)
pgoff_t index, int size, int sizebits, gfp_t gfp)
{ {
struct inode *inode = bdev->bd_inode; struct inode *inode = bdev->bd_inode;
struct folio *folio; struct folio *folio;
struct buffer_head *bh; struct buffer_head *bh;
sector_t end_block; sector_t end_block = 0;
int ret = 0;
folio = __filemap_get_folio(inode->i_mapping, index, folio = __filemap_get_folio(inode->i_mapping, index,
FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp); FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp);
if (IS_ERR(folio)) if (IS_ERR(folio))
return PTR_ERR(folio); return false;
bh = folio_buffers(folio); bh = folio_buffers(folio);
if (bh) { if (bh) {
if (bh->b_size == size) { if (bh->b_size == size) {
end_block = folio_init_buffers(folio, bdev, end_block = folio_init_buffers(folio, bdev,
(sector_t)index << sizebits, size); (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)) if (!try_to_free_buffers(folio))
goto failed; goto unlock;
} }
ret = -ENOMEM;
bh = folio_alloc_buffers(folio, size, gfp | __GFP_ACCOUNT); bh = folio_alloc_buffers(folio, size, gfp | __GFP_ACCOUNT);
if (!bh) if (!bh)
goto failed; goto unlock;
/* /*
* Link the folio to the buffers and initialise them. Take the * 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, end_block = folio_init_buffers(folio, bdev,
(sector_t)index << sizebits, size); (sector_t)index << sizebits, size);
spin_unlock(&inode->i_mapping->private_lock); spin_unlock(&inode->i_mapping->private_lock);
done: unlock:
ret = (block < end_block) ? 1 : -ENXIO;
failed:
folio_unlock(folio); folio_unlock(folio);
folio_put(folio); folio_put(folio);
return ret; return block < end_block;
} }
/* /*
* Create buffers for the specified block device block's page. If * Create buffers for the specified block device block's folio. If
* that page was dirty, the buffers are set dirty also. * that folio was dirty, the buffers are set dirty also. Returns false
* if we've hit a permanent error.
*/ */
static int static bool grow_buffers(struct block_device *bdev, sector_t block,
grow_buffers(struct block_device *bdev, sector_t block, int size, gfp_t gfp) unsigned size, gfp_t gfp)
{ {
pgoff_t index; pgoff_t index;
int sizebits; int sizebits;
@ -1099,11 +1101,11 @@ grow_buffers(struct block_device *bdev, sector_t block, int size, gfp_t gfp)
"device %pg\n", "device %pg\n",
__func__, (unsigned long long)block, __func__, (unsigned long long)block,
bdev); bdev);
return -EIO; return false;
} }
/* Create a page with the proper size buffers.. */ /* Create a folio with the proper size buffers */
return grow_dev_page(bdev, block, index, size, sizebits, gfp); return grow_dev_folio(bdev, block, index, size, sizebits, gfp);
} }
static struct buffer_head * static struct buffer_head *
@ -1124,14 +1126,12 @@ __getblk_slow(struct block_device *bdev, sector_t block,
for (;;) { for (;;) {
struct buffer_head *bh; struct buffer_head *bh;
int ret;
bh = __find_get_block(bdev, block, size); bh = __find_get_block(bdev, block, size);
if (bh) if (bh)
return bh; return bh;
ret = grow_buffers(bdev, block, size, gfp); if (!grow_buffers(bdev, block, size, gfp))
if (ret < 0)
return NULL; return NULL;
} }
} }