[PATCH 14/15] xfs: split xfs_free_file_space in manageable pieces

Christoph Hellwig
2016-05-09T08:48:23Z

fs/xfs/xfs_bmap_util.c | 252 +++++++++++++++++++++++++++----------------------
1 file changed, 137 insertions(+), 115 deletions(-)

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 3246ebc..5d030b0 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1191,30 +1191,132 @@ xfs_zero_remaining_bytes(
return error;
}

+static int
+xfs_unmap_extent(
+ struct xfs_inode *ip,
+ xfs_fileoff_t startoffset_fsb,
+ xfs_filblks_t len_fsb,
+ int *done)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_trans *tp;
+ struct xfs_bmap_free free_list;
+ xfs_fsblock_t firstfsb;
+ uint resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
+ int error;
+
+ error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp);
+ if (error) {
+ ASSERT(error == -ENOSPC || XFS_FORCED_SHUTDOWN(mp));
+ return error;
+ }
+
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ error = xfs_trans_reserve_quota(tp, mp, ip->i_udquot, ip->i_gdquot,
+ ip->i_pdquot, resblks, 0, XFS_QMOPT_RES_REGBLKS);
+ if (error)
+ goto out_trans_cancel;
+
+ xfs_trans_ijoin(tp, ip, 0);
+
+ xfs_bmap_init(&free_list, &firstfsb);
+ error = xfs_bunmapi(tp, ip, startoffset_fsb, len_fsb, 0, 2, &firstfsb,
+ &free_list, done);
+ if (error)
+ goto out_bmap_cancel;
+
+ error = xfs_bmap_finish(&tp, &free_list, NULL);
+ if (error)
+ goto out_bmap_cancel;
+
+ error = xfs_trans_commit(tp);
+out_unlock:
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ return error;
+
+out_bmap_cancel:
+ xfs_bmap_cancel(&free_list);
+out_trans_cancel:
+ xfs_trans_cancel(tp);
+ goto out_unlock;
+}
+
+static int
+xfs_adjust_extent_unmap_boundaries(
+ struct xfs_inode *ip,
+ xfs_fileoff_t *startoffset_fsb,
+ xfs_fileoff_t *endoffset_fsb)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_bmbt_irec imap;
+ int nimap, error;
+ xfs_extlen_t mod = 0;
+
+ nimap = 1;
+ error = xfs_bmapi_read(ip, *startoffset_fsb, 1, &imap, &nimap, 0);
+ if (error)
+ return error;
+
+ if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
+ xfs_daddr_t block;
+
+ ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
+ block = imap.br_startblock;
+ mod = do_div(block, mp->m_sb.sb_rextsize);
+ if (mod)
+ *startoffset_fsb += mp->m_sb.sb_rextsize - mod;
+ }
+
+ nimap = 1;
+ error = xfs_bmapi_read(ip, *endoffset_fsb - 1, 1, &imap, &nimap, 0);
+ if (error)
+ return error;
+
+ if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
+ ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
+ mod++;
+ if (mod && mod != mp->m_sb.sb_rextsize)
+ *endoffset_fsb -= mod;
+ }
+
+ return 0;
+}
+
+static int
+xfs_flush_unmap_range(
+ struct xfs_inode *ip,
+ xfs_off_t offset,
+ xfs_off_t len)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct inode *inode = VFS_I(ip);
+ xfs_off_t rounding, start, end;
+ int error;
+
+ /* wait for the completion of any pending DIOs */
+ inode_dio_wait(inode);
+
+ rounding = max_t(xfs_off_t, 1 << mp->m_sb.sb_blocklog, PAGE_SIZE);
+ start = round_down(offset, rounding);
+ end = round_up(offset + len, rounding) - 1;
+
+ error = filemap_write_and_wait_range(inode->i_mapping, start, end);
+ if (error)
+ return error;
+ truncate_pagecache_range(inode, start, end);
+ return 0;
+}
+
int
xfs_free_file_space(
struct xfs_inode *ip,
xfs_off_t offset,
xfs_off_t len)
{
- int done;
- xfs_fileoff_t endoffset_fsb;
- int error;
- xfs_fsblock_t firstfsb;
- xfs_bmap_free_t free_list;
- xfs_bmbt_irec_t imap;
- xfs_off_t ioffset;
- xfs_off_t iendoffset;
- xfs_extlen_t mod=0;
- xfs_mount_t *mp;
- int nimap;
- uint resblks;
- xfs_off_t rounding;
- int rt;
+ struct xfs_mount *mp = ip->i_mount;
xfs_fileoff_t startoffset_fsb;
- xfs_trans_t *tp;
-
- mp = ip->i_mount;
+ xfs_fileoff_t endoffset_fsb;
+ int done, error;

trace_xfs_free_file_space(ip);

@@ -1222,60 +1324,30 @@ xfs_free_file_space(
if (error)
return error;

- error = 0;
if (len <= 0) /* if nothing being freed */
- return error;
- rt = XFS_IS_REALTIME_INODE(ip);
- startoffset_fsb = XFS_B_TO_FSB(mp, offset);
- endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
-
- /* wait for the completion of any pending DIOs */
- inode_dio_wait(VFS_I(ip));
+ return 0;

- rounding = max_t(xfs_off_t, 1 << mp->m_sb.sb_blocklog, PAGE_CACHE_SIZE);
- ioffset = round_down(offset, rounding);
- iendoffset = round_up(offset + len, rounding) - 1;
- error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping, ioffset,
- iendoffset);
+ error = xfs_flush_unmap_range(ip, offset, len);
if (error)
- goto out;
- truncate_pagecache_range(VFS_I(ip), ioffset, iendoffset);
+ return error;
+
+ startoffset_fsb = XFS_B_TO_FSB(mp, offset);
+ endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);

/*
- * Need to zero the stuff we're not freeing, on disk.
- * If it's a realtime file & can't use unwritten extents then we
- * actually need to zero the extent edges. Otherwise xfs_bunmapi
- * will take care of it for us.
+ * Need to zero the stuff we're not freeing, on disk. If it's a RT file
+ * and we can't use unwritten extents then we actually need to ensure
+ * to zero the whole extent, otherwise we just need to take of block
+ * boundaries, and xfs_bunmapi will handle the rest.
*/
- if (rt && !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
- nimap = 1;
- error = xfs_bmapi_read(ip, startoffset_fsb, 1,
- &imap, &nimap, 0);
+ if (XFS_IS_REALTIME_INODE(ip) &&
+ !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
+ error = xfs_adjust_extent_unmap_boundaries(ip, &startoffset_fsb,
+ &endoffset_fsb);
if (error)
- goto out;
- ASSERT(nimap == 0 || nimap == 1);
- if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
- xfs_daddr_t block;
-
- ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
- block = imap.br_startblock;
- mod = do_div(block, mp->m_sb.sb_rextsize);
- if (mod)
- startoffset_fsb += mp->m_sb.sb_rextsize - mod;
- }
- nimap = 1;
- error = xfs_bmapi_read(ip, endoffset_fsb - 1, 1,
- &imap, &nimap, 0);
- if (error)
- goto out;
- ASSERT(nimap == 0 || nimap == 1);
- if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
- ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
- mod++;
- if (mod && (mod != mp->m_sb.sb_rextsize))
- endoffset_fsb -= mod;
- }
+ return error;
}
+
if ((done = (endoffset_fsb <= startoffset_fsb)))
/*
* One contiguous piece to clear
@@ -1295,62 +1367,12 @@ xfs_free_file_space(
offset + len - 1);
}

- /*
- * free file space until done or until there is an error
- */
- resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
while (!error && !done) {
-
- /*
- * allocate and setup the transaction. Allow this
- * transaction to dip into the reserve blocks to ensure
- * the freeing of the space succeeds at ENOSPC.
- */
- error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0,
- &tp);
- if (error) {
- ASSERT(error == -ENOSPC || XFS_FORCED_SHUTDOWN(mp));
- break;
- }
- xfs_ilock(ip, XFS_ILOCK_EXCL);
- error = xfs_trans_reserve_quota(tp, mp,
- ip->i_udquot, ip->i_gdquot, ip->i_pdquot,
- resblks, 0, XFS_QMOPT_RES_REGBLKS);
- if (error)
- goto error1;
-
- xfs_trans_ijoin(tp, ip, 0);
-
- /*
- * issue the bunmapi() call to free the blocks
- */
- xfs_bmap_init(&free_list, &firstfsb);
- error = xfs_bunmapi(tp, ip, startoffset_fsb,
- endoffset_fsb - startoffset_fsb,
- 0, 2, &firstfsb, &free_list, &done);
- if (error)
- goto error0;
-
- /*
- * complete the transaction
- */
- error = xfs_bmap_finish(&tp, &free_list, NULL);
- if (error)
- goto error0;
-
- error = xfs_trans_commit(tp);
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ error = xfs_unmap_extent(ip, startoffset_fsb,
+ endoffset_fsb - startoffset_fsb, &done);
}

- out:
return error;
-
- error0:
- xfs_bmap_cancel(&free_list);
- error1:
- xfs_trans_cancel(tp);
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
- goto out;
}

/*