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xfs: simplify xfs_aops_discard_page

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Instead of looking at the buffer heads to see if a block is delalloc just
call xfs_bmap_punch_delalloc_range on the whole page - this will leave
any non-delalloc block intact and handle the iteration for us.  As a side
effect one more place stops caring about buffer heads and we can remove the
xfs_check_page_type function entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Christoph Hellwig 2018-07-11 22:25:57 -07:00 committed by Darrick J. Wong
parent 8b2e77c163
commit 0362572138
1 changed files with 9 additions and 76 deletions
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85
fs/xfs/xfs_aops.c
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@ -710,49 +710,6 @@ xfs_map_at_offset(
clear_buffer_unwritten(bh);
}
/*
* Test if a given page contains at least one buffer of a given @type.
* If @check_all_buffers is true, then we walk all the buffers in the page to
* try to find one of the type passed in. If it is not set, then the caller only
* needs to check the first buffer on the page for a match.
*/
STATIC bool
xfs_check_page_type(
struct page *page,
unsigned int type,
bool check_all_buffers)
{
struct buffer_head *bh;
struct buffer_head *head;
if (PageWriteback(page))
return false;
if (!page->mapping)
return false;
if (!page_has_buffers(page))
return false;
bh = head = page_buffers(page);
do {
if (buffer_unwritten(bh)) {
if (type == XFS_IO_UNWRITTEN)
return true;
} else if (buffer_delay(bh)) {
if (type == XFS_IO_DELALLOC)
return true;
} else if (buffer_dirty(bh) && buffer_mapped(bh)) {
if (type == XFS_IO_OVERWRITE)
return true;
}
/* If we are only checking the first buffer, we are done now. */
if (!check_all_buffers)
break;
} while ((bh = bh->b_this_page) != head);
return false;
}
STATIC void
xfs_vm_invalidatepage(
struct page *page,
@ -784,9 +741,6 @@ xfs_vm_invalidatepage(
* transaction. Indeed - if we get ENOSPC errors, we have to be able to do this
* truncation without a transaction as there is no space left for block
* reservation (typically why we see a ENOSPC in writeback).
*
* This is not a performance critical path, so for now just do the punching a
* buffer head at a time.
*/
STATIC void
xfs_aops_discard_page(
@ -794,47 +748,26 @@ xfs_aops_discard_page(
{
struct inode *inode = page->mapping->host;
struct xfs_inode *ip = XFS_I(inode);
struct buffer_head *bh, *head;
struct xfs_mount *mp = ip->i_mount;
loff_t offset = page_offset(page);
xfs_fileoff_t start_fsb = XFS_B_TO_FSBT(mp, offset);
int error;
if (!xfs_check_page_type(page, XFS_IO_DELALLOC, true))
if (XFS_FORCED_SHUTDOWN(mp))
goto out_invalidate;
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
goto out_invalidate;
xfs_alert(ip->i_mount,
xfs_alert(mp,
"page discard on page "PTR_FMT", inode 0x%llx, offset %llu.",
page, ip->i_ino, offset);
xfs_ilock(ip, XFS_ILOCK_EXCL);
bh = head = page_buffers(page);
do {
int error;
xfs_fileoff_t start_fsb;
if (!buffer_delay(bh))
goto next_buffer;
start_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
error = xfs_bmap_punch_delalloc_range(ip, start_fsb, 1);
if (error) {
/* something screwed, just bail */
if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
xfs_alert(ip->i_mount,
"page discard unable to remove delalloc mapping.");
}
break;
}
next_buffer:
offset += i_blocksize(inode);
} while ((bh = bh->b_this_page) != head);
error = xfs_bmap_punch_delalloc_range(ip, start_fsb,
PAGE_SIZE / i_blocksize(inode));
xfs_iunlock(ip, XFS_ILOCK_EXCL);
if (error && !XFS_FORCED_SHUTDOWN(mp))
xfs_alert(mp, "page discard unable to remove delalloc mapping.");
out_invalidate:
xfs_vm_invalidatepage(page, 0, PAGE_SIZE);
return;
}
static int