From: Christoph Hellwig <hch@lst.de>
To: Goldwyn Rodrigues <rgoldwyn@suse.com>,
linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc: "Darrick J . Wong" <darrick.wong@oracle.com>
Subject: [PATCH 19/20] xfs: cleanup xfs_iomap_write_unwritten
Date: Tue, 8 Oct 2019 09:15:26 +0200 [thread overview]
Message-ID: <20191008071527.29304-20-hch@lst.de> (raw)
In-Reply-To: <20191008071527.29304-1-hch@lst.de>
Move more checks into the helpers that determine if we need a COW
operation or allocation and split the return path for when an existing
data for allocation has been found versus a new allocation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/xfs_iomap.c | 74 ++++++++++++++++++++++++----------------------
1 file changed, 38 insertions(+), 36 deletions(-)
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 7a3fcfe5662c..cc3d8fa011fc 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -642,23 +642,42 @@ xfs_iomap_write_unwritten(
static inline bool
imap_needs_alloc(
struct inode *inode,
+ unsigned flags,
struct xfs_bmbt_irec *imap,
int nimaps)
{
- return !nimaps ||
- imap->br_startblock == HOLESTARTBLOCK ||
- imap->br_startblock == DELAYSTARTBLOCK ||
- (IS_DAX(inode) && imap->br_state == XFS_EXT_UNWRITTEN);
+ /* don't allocate blocks when just zeroing */
+ if (flags & IOMAP_ZERO)
+ return false;
+ if (!nimaps ||
+ imap->br_startblock == HOLESTARTBLOCK ||
+ imap->br_startblock == DELAYSTARTBLOCK)
+ return true;
+ /* we convert unwritten extents before copying the data for DAX */
+ if (IS_DAX(inode) && imap->br_state == XFS_EXT_UNWRITTEN)
+ return true;
+ return false;
}
static inline bool
-needs_cow_for_zeroing(
+imap_needs_cow(
+ struct xfs_inode *ip,
+ unsigned int flags,
struct xfs_bmbt_irec *imap,
int nimaps)
{
- return nimaps &&
- imap->br_startblock != HOLESTARTBLOCK &&
- imap->br_state != XFS_EXT_UNWRITTEN;
+ if (!xfs_is_cow_inode(ip))
+ return false;
+
+ /* when zeroing we don't have to COW holes or unwritten extents */
+ if (flags & IOMAP_ZERO) {
+ if (!nimaps ||
+ imap->br_startblock == HOLESTARTBLOCK ||
+ imap->br_state == XFS_EXT_UNWRITTEN)
+ return false;
+ }
+
+ return true;
}
static int
@@ -734,7 +753,6 @@ xfs_direct_write_iomap_begin(
xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, length);
int nimaps = 1, error = 0;
bool shared = false;
- u16 iomap_flags = 0;
unsigned lockmode;
ASSERT(flags & (IOMAP_WRITE | IOMAP_ZERO));
@@ -761,12 +779,7 @@ xfs_direct_write_iomap_begin(
* Break shared extents if necessary. Checks for non-blocking IO have
* been done up front, so we don't need to do them here.
*/
- if (xfs_is_cow_inode(ip)) {
- /* if zeroing doesn't need COW allocation, then we are done. */
- if ((flags & IOMAP_ZERO) &&
- !needs_cow_for_zeroing(&imap, nimaps))
- goto out_found;
-
+ if (imap_needs_cow(ip, flags, &imap, nimaps)) {
/* may drop and re-acquire the ilock */
error = xfs_reflink_allocate_cow(ip, &imap, &cmap, &shared,
&lockmode, flags & IOMAP_DIRECT);
@@ -778,18 +791,17 @@ xfs_direct_write_iomap_begin(
length = XFS_FSB_TO_B(mp, end_fsb) - offset;
}
- /* Don't need to allocate over holes when doing zeroing operations. */
- if (flags & IOMAP_ZERO)
- goto out_found;
+ if (imap_needs_alloc(inode, flags, &imap, nimaps))
+ goto allocate_blocks;
- if (!imap_needs_alloc(inode, &imap, nimaps))
- goto out_found;
+ xfs_iunlock(ip, lockmode);
+ trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap);
+ return xfs_bmbt_to_iomap(ip, iomap, &imap, 0);
- /* If nowait is set bail since we are going to make allocations. */
- if (flags & IOMAP_NOWAIT) {
- error = -EAGAIN;
+allocate_blocks:
+ error = -EAGAIN;
+ if (flags & IOMAP_NOWAIT)
goto out_unlock;
- }
/*
* We cap the maximum length we map to a sane size to keep the chunks
@@ -808,22 +820,12 @@ xfs_direct_write_iomap_begin(
*/
if (lockmode == XFS_ILOCK_EXCL)
xfs_ilock_demote(ip, lockmode);
- error = xfs_iomap_write_direct(ip, offset, length, &imap,
- nimaps);
+ error = xfs_iomap_write_direct(ip, offset, length, &imap, nimaps);
if (error)
return error;
- iomap_flags |= IOMAP_F_NEW;
trace_xfs_iomap_alloc(ip, offset, length, XFS_DATA_FORK, &imap);
-
-out_finish:
- return xfs_bmbt_to_iomap(ip, iomap, &imap, iomap_flags);
-
-out_found:
- ASSERT(nimaps);
- xfs_iunlock(ip, lockmode);
- trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap);
- goto out_finish;
+ return xfs_bmbt_to_iomap(ip, iomap, &imap, IOMAP_F_NEW);
out_found_cow:
xfs_iunlock(ip, lockmode);
--
2.20.1
next prev parent reply other threads:[~2019-10-08 7:16 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-08 7:15 iomap and xfs COW cleanups v2 Christoph Hellwig
2019-10-08 7:15 ` [PATCH 01/20] iomap: better document the IOMAP_F_* flags Christoph Hellwig
2019-10-08 7:15 ` [PATCH 02/20] iomap: remove the unused iomap argument to __iomap_write_end Christoph Hellwig
2019-10-08 7:15 ` [PATCH 03/20] iomap: always use AOP_FLAG_NOFS in iomap_write_begin Christoph Hellwig
2019-10-08 7:15 ` [PATCH 04/20] iomap: ignore non-shared or non-data blocks in xfs_file_dirty Christoph Hellwig
2019-10-08 7:15 ` [PATCH 05/20] iomap: move the zeroing case out of iomap_read_page_sync Christoph Hellwig
2019-10-08 7:15 ` [PATCH 06/20] iomap: use write_begin to read pages to unshare Christoph Hellwig
2019-10-08 15:12 ` Darrick J. Wong
2019-10-08 7:15 ` [PATCH 07/20] iomap: renumber IOMAP_HOLE to 0 Christoph Hellwig
2019-10-08 15:01 ` Darrick J. Wong
2019-10-08 7:15 ` [PATCH 08/20] iomap: use a srcmap for a read-modify-write I/O Christoph Hellwig
2019-10-08 15:00 ` Darrick J. Wong
2019-10-09 6:28 ` Christoph Hellwig
2019-10-09 17:16 ` Darrick J. Wong
2019-10-14 23:27 ` Darrick J. Wong
2019-10-15 13:00 ` Goldwyn Rodrigues
2019-10-08 7:15 ` [PATCH 09/20] xfs: also call xfs_file_iomap_end_delalloc for zeroing operations Christoph Hellwig
2019-10-08 7:15 ` [PATCH 10/20] xfs: remove xfs_reflink_dirty_extents Christoph Hellwig
2019-10-08 15:20 ` Darrick J. Wong
2019-10-08 7:15 ` [PATCH 11/20] xfs: pass two imaps to xfs_reflink_allocate_cow Christoph Hellwig
2019-10-08 7:15 ` [PATCH 12/20] xfs: refactor xfs_file_iomap_begin_delay Christoph Hellwig
2019-10-08 7:15 ` [PATCH 13/20] xfs: fill out the srcmap in iomap_begin Christoph Hellwig
2019-10-08 15:26 ` Darrick J. Wong
2019-10-08 7:15 ` [PATCH 14/20] xfs: factor out a helper to calculate the end_fsb Christoph Hellwig
2019-10-08 7:15 ` [PATCH 15/20] xfs: split out a new set of read-only iomap ops Christoph Hellwig
2019-10-08 15:27 ` Darrick J. Wong
2019-10-08 7:15 ` [PATCH 16/20] xfs: move xfs_file_iomap_begin_delay around Christoph Hellwig
2019-10-08 7:15 ` [PATCH 17/20] xfs: split the iomap ops for buffered vs direct writes Christoph Hellwig
2019-10-08 15:28 ` Darrick J. Wong
2019-10-08 7:15 ` [PATCH 18/20] xfs: rename the whichfork variable in xfs_buffered_write_iomap_begin Christoph Hellwig
2019-10-08 7:15 ` Christoph Hellwig [this message]
2019-10-08 7:15 ` [PATCH 20/20] xfs: improve the IOMAP_NOWAIT check for COW inodes Christoph Hellwig
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