Previously, xfs_bmap_add_extent_unwritten_real() was just used for
unwritten conversion. However, the code could be sightly modified
to update a real allocated extent. It can be then used to avoid
unnecessary bmbt unmap due to end COW.
Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
---
fs/xfs/libxfs/xfs_bmap.c | 65 ++++++++++++++++++++++++++--------------
fs/xfs/libxfs/xfs_bmap.h | 4 +--
fs/xfs/xfs_reflink.c | 5 ++--
3 files changed, 47 insertions(+), 27 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 14d1a806ba15..a10476dee701 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -1930,22 +1930,26 @@ xfs_bmap_add_extent_delay_real(
}
/*
- * Convert an unwritten allocation to a real allocation or vice versa.
+ * Update a real allocated extent (including converting an unwritten
+ * allocation to a real allocation or vice versa.)
*/
int /* error */
-xfs_bmap_add_extent_unwritten_real(
+xfs_bmap_update_extent_real(
struct xfs_trans *tp,
struct xfs_inode *ip, /* incore inode pointer */
int whichfork,
struct xfs_iext_cursor *icur,
struct xfs_btree_cur **curp, /* if *curp is null, not a btree */
struct xfs_bmbt_irec *new, /* new data to add to file extents */
- int *logflagsp) /* inode logging flags */
+ int *logflagsp, /* inode logging flags */
+ bool convert)
{
struct xfs_btree_cur *cur; /* btree cursor */
int error; /* error return value */
int i; /* temp state */
struct xfs_ifork *ifp; /* inode fork pointer */
+ xfs_fileoff_t del_startoff; /* start offset of del entry */
+ xfs_exntst_t del_state;
xfs_fileoff_t new_endoff; /* end offset of new entry */
struct xfs_bmbt_irec left, right; /* neighbor extent entries */
struct xfs_bmbt_irec prev; /* previous old extent */
@@ -1953,6 +1957,7 @@ xfs_bmap_add_extent_unwritten_real(
int state = xfs_bmap_fork_to_state(whichfork);
struct xfs_mount *mp = ip->i_mount;
struct xfs_bmbt_irec old;
+ int tmp_logflags; /* partial log flag return val */
*logflagsp = 0;
@@ -1968,8 +1973,11 @@ xfs_bmap_add_extent_unwritten_real(
*/
error = 0;
xfs_iext_get_extent(ifp, icur, &prev);
- ASSERT(new->br_state != prev.br_state);
+ ASSERT(!convert || new->br_state != prev.br_state);
new_endoff = new->br_startoff + new->br_blockcount;
+ del_startoff = prev.br_startblock +
+ new->br_startoff - prev.br_startoff;
+ del_state = prev.br_state;
ASSERT(prev.br_startoff <= new->br_startoff);
ASSERT(prev.br_startoff + prev.br_blockcount >= new_endoff);
@@ -2129,6 +2137,7 @@ xfs_bmap_add_extent_unwritten_real(
*/
prev.br_blockcount += right.br_blockcount;
prev.br_state = new->br_state;
+ prev.br_startblock = new->br_startblock;
xfs_iext_next(ifp, icur);
xfs_iext_remove(ip, icur, state);
@@ -2171,6 +2180,7 @@ xfs_bmap_add_extent_unwritten_real(
* Neither the left nor right neighbors are contiguous with
* the new one.
*/
+ prev.br_startblock = new->br_startblock;
prev.br_state = new->br_state;
xfs_iext_update_extent(ip, state, icur, &prev);
@@ -2362,7 +2372,8 @@ xfs_bmap_add_extent_unwritten_real(
right.br_startoff = new_endoff;
right.br_blockcount =
old.br_startoff + old.br_blockcount - new_endoff;
- right.br_startblock = new->br_startblock + new->br_blockcount;
+ right.br_startblock = old.br_startblock + prev.br_blockcount +
+ new->br_blockcount;
right.br_state = prev.br_state;
xfs_iext_update_extent(ip, state, icur, &prev);
@@ -2430,20 +2441,30 @@ xfs_bmap_add_extent_unwritten_real(
}
/* update reverse mappings */
- xfs_rmap_convert_extent(mp, tp, ip, whichfork, new);
+ if (!convert) {
+ old = *new;
+ old.br_startblock = del_startoff;
+ old.br_state = del_state;
+ xfs_rmap_unmap_extent(tp, ip, whichfork, &old);
+ xfs_rmap_map_extent(tp, ip, whichfork, new);
+ } else {
+ xfs_rmap_convert_extent(mp, tp, ip, whichfork, new);
+ }
- /* convert to a btree if necessary */
+ /* convert to a btree or extents if necessary */
if (xfs_bmap_needs_btree(ip, whichfork)) {
- int tmp_logflags; /* partial log flag return val */
-
ASSERT(cur == NULL);
error = xfs_bmap_extents_to_btree(tp, ip, &cur, 0,
&tmp_logflags, whichfork);
- *logflagsp |= tmp_logflags;
- if (error)
- goto done;
+ } else if (!convert) {
+ error = xfs_bmap_btree_to_extents(tp, ip, cur,
+ &tmp_logflags, whichfork);
}
+ *logflagsp |= tmp_logflags;
+ if (error)
+ goto done;
+
/* clear out the allocated field, done with it now in any case. */
if (cur) {
cur->bc_ino.allocated = 0;
@@ -4216,8 +4237,8 @@ xfs_bmapi_convert_unwritten(
return error;
}
- error = xfs_bmap_add_extent_unwritten_real(bma->tp, bma->ip, whichfork,
- &bma->icur, &bma->cur, mval, &tmp_logflags);
+ error = xfs_bmap_update_extent_real(bma->tp, bma->ip, whichfork,
+ &bma->icur, &bma->cur, mval, &tmp_logflags, true);
/*
* Log the inode core unconditionally in the unwritten extent conversion
* path because the conversion might not have done so (e.g., if the
@@ -5444,9 +5465,9 @@ __xfs_bunmapi(
del.br_blockcount = mod;
}
del.br_state = XFS_EXT_UNWRITTEN;
- error = xfs_bmap_add_extent_unwritten_real(tp, ip,
+ error = xfs_bmap_update_extent_real(tp, ip,
whichfork, &icur, &cur, &del,
- &logflags);
+ &logflags, true);
if (error)
goto error0;
goto nodelete;
@@ -5503,18 +5524,18 @@ __xfs_bunmapi(
prev.br_startblock += mod;
prev.br_blockcount -= mod;
prev.br_state = XFS_EXT_UNWRITTEN;
- error = xfs_bmap_add_extent_unwritten_real(tp,
- ip, whichfork, &icur, &cur,
- &prev, &logflags);
+ error = xfs_bmap_update_extent_real(tp, ip,
+ whichfork, &icur, &cur, &prev,
+ &logflags, true);
if (error)
goto error0;
goto nodelete;
} else {
ASSERT(del.br_state == XFS_EXT_NORM);
del.br_state = XFS_EXT_UNWRITTEN;
- error = xfs_bmap_add_extent_unwritten_real(tp,
- ip, whichfork, &icur, &cur,
- &del, &logflags);
+ error = xfs_bmap_update_extent_real(tp, ip,
+ whichfork, &icur, &cur, &del,
+ &logflags, true);
if (error)
goto error0;
goto nodelete;
diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
index 03d9aaf87413..c52ff94786e2 100644
--- a/fs/xfs/libxfs/xfs_bmap.h
+++ b/fs/xfs/libxfs/xfs_bmap.h
@@ -216,10 +216,10 @@ int xfs_bmapi_reserve_delalloc(struct xfs_inode *ip, int whichfork,
int eof);
int xfs_bmapi_convert_delalloc(struct xfs_inode *ip, int whichfork,
xfs_off_t offset, struct iomap *iomap, unsigned int *seq);
-int xfs_bmap_add_extent_unwritten_real(struct xfs_trans *tp,
+int xfs_bmap_update_extent_real(struct xfs_trans *tp,
struct xfs_inode *ip, int whichfork,
struct xfs_iext_cursor *icur, struct xfs_btree_cur **curp,
- struct xfs_bmbt_irec *new, int *logflagsp);
+ struct xfs_bmbt_irec *new, int *logflagsp, bool convert);
enum xfs_bmap_intent_type {
XFS_BMAP_MAP = 1,
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index db70060e7bf6..276387a6a85d 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -266,9 +266,8 @@ xfs_reflink_convert_cow_locked(
continue;
got.br_state = XFS_EXT_NORM;
- error = xfs_bmap_add_extent_unwritten_real(NULL, ip,
- XFS_COW_FORK, &icur, &dummy_cur, &got,
- &dummy_logflags);
+ error = xfs_bmap_update_extent_real(NULL, ip, XFS_COW_FORK,
+ &icur, &dummy_cur, &got, &dummy_logflags, true);
if (error)
return error;
} while (xfs_iext_next_extent(ip->i_cowfp, &icur, &got));
--
2.24.4
