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Merge branch 'xfs-shift-extents-rework' into for-next

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This commit is contained in:
Dave Chinner
2014-09-23 15:51:14 +10:00
parent a4241aebe9 8b5279e33f
commit f6d31f4b04
4 changed files with 289 additions and 153 deletions
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365
fs/xfs/libxfs/xfs_bmap.c
View File

@@ -5403,23 +5403,224 @@ error0:
return error;
}
/*
* Determine whether an extent shift can be accomplished by a merge with the
* extent that precedes the target hole of the shift.
*/
STATIC bool
xfs_bmse_can_merge(
struct xfs_bmbt_irec *left, /* preceding extent */
struct xfs_bmbt_irec *got, /* current extent to shift */
xfs_fileoff_t shift) /* shift fsb */
{
xfs_fileoff_t startoff;
startoff = got->br_startoff - shift;
/*
* The extent, once shifted, must be adjacent in-file and on-disk with
* the preceding extent.
*/
if ((left->br_startoff + left->br_blockcount != startoff) ||
(left->br_startblock + left->br_blockcount != got->br_startblock) ||
(left->br_state != got->br_state) ||
(left->br_blockcount + got->br_blockcount > MAXEXTLEN))
return false;
return true;
}
/*
* A bmap extent shift adjusts the file offset of an extent to fill a preceding
* hole in the file. If an extent shift would result in the extent being fully
* adjacent to the extent that currently precedes the hole, we can merge with
* the preceding extent rather than do the shift.
*
* This function assumes the caller has verified a shift-by-merge is possible
* with the provided extents via xfs_bmse_can_merge().
*/
STATIC int
xfs_bmse_merge(
struct xfs_inode *ip,
int whichfork,
xfs_fileoff_t shift, /* shift fsb */
int current_ext, /* idx of gotp */
struct xfs_bmbt_rec_host *gotp, /* extent to shift */
struct xfs_bmbt_rec_host *leftp, /* preceding extent */
struct xfs_btree_cur *cur,
int *logflags) /* output */
{
struct xfs_ifork *ifp;
struct xfs_bmbt_irec got;
struct xfs_bmbt_irec left;
xfs_filblks_t blockcount;
int error, i;
ifp = XFS_IFORK_PTR(ip, whichfork);
xfs_bmbt_get_all(gotp, &got);
xfs_bmbt_get_all(leftp, &left);
blockcount = left.br_blockcount + got.br_blockcount;
ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
ASSERT(xfs_bmse_can_merge(&left, &got, shift));
/*
* Merge the in-core extents. Note that the host record pointers and
* current_ext index are invalid once the extent has been removed via
* xfs_iext_remove().
*/
xfs_bmbt_set_blockcount(leftp, blockcount);
xfs_iext_remove(ip, current_ext, 1, 0);
/*
* Update the on-disk extent count, the btree if necessary and log the
* inode.
*/
XFS_IFORK_NEXT_SET(ip, whichfork,
XFS_IFORK_NEXTENTS(ip, whichfork) - 1);
*logflags |= XFS_ILOG_CORE;
if (!cur) {
*logflags |= XFS_ILOG_DEXT;
return 0;
}
/* lookup and remove the extent to merge */
error = xfs_bmbt_lookup_eq(cur, got.br_startoff, got.br_startblock,
got.br_blockcount, &i);
if (error)
goto out_error;
XFS_WANT_CORRUPTED_GOTO(i == 1, out_error);
error = xfs_btree_delete(cur, &i);
if (error)
goto out_error;
XFS_WANT_CORRUPTED_GOTO(i == 1, out_error);
/* lookup and update size of the previous extent */
error = xfs_bmbt_lookup_eq(cur, left.br_startoff, left.br_startblock,
left.br_blockcount, &i);
if (error)
goto out_error;
XFS_WANT_CORRUPTED_GOTO(i == 1, out_error);
left.br_blockcount = blockcount;
error = xfs_bmbt_update(cur, left.br_startoff, left.br_startblock,
left.br_blockcount, left.br_state);
if (error)
goto out_error;
return 0;
out_error:
return error;
}
/*
* Shift a single extent.
*/
STATIC int
xfs_bmse_shift_one(
struct xfs_inode *ip,
int whichfork,
xfs_fileoff_t offset_shift_fsb,
int *current_ext,
struct xfs_bmbt_rec_host *gotp,
struct xfs_btree_cur *cur,
int *logflags)
{
struct xfs_ifork *ifp;
xfs_fileoff_t startoff;
struct xfs_bmbt_rec_host *leftp;
struct xfs_bmbt_irec got;
struct xfs_bmbt_irec left;
int error;
int i;
ifp = XFS_IFORK_PTR(ip, whichfork);
xfs_bmbt_get_all(gotp, &got);
startoff = got.br_startoff - offset_shift_fsb;
/* delalloc extents should be prevented by caller */
XFS_WANT_CORRUPTED_GOTO(!isnullstartblock(got.br_startblock),
out_error);
/*
* If this is the first extent in the file, make sure there's enough
* room at the start of the file and jump right to the shift as there's
* no left extent to merge.
*/
if (*current_ext == 0) {
if (got.br_startoff < offset_shift_fsb)
return -EINVAL;
goto shift_extent;
}
/* grab the left extent and check for a large enough hole */
leftp = xfs_iext_get_ext(ifp, *current_ext - 1);
xfs_bmbt_get_all(leftp, &left);
if (startoff < left.br_startoff + left.br_blockcount)
return -EINVAL;
/* check whether to merge the extent or shift it down */
if (!xfs_bmse_can_merge(&left, &got, offset_shift_fsb))
goto shift_extent;
return xfs_bmse_merge(ip, whichfork, offset_shift_fsb, *current_ext,
gotp, leftp, cur, logflags);
shift_extent:
/*
* Increment the extent index for the next iteration, update the start
* offset of the in-core extent and update the btree if applicable.
*/
(*current_ext)++;
xfs_bmbt_set_startoff(gotp, startoff);
*logflags |= XFS_ILOG_CORE;
if (!cur) {
*logflags |= XFS_ILOG_DEXT;
return 0;
}
error = xfs_bmbt_lookup_eq(cur, got.br_startoff, got.br_startblock,
got.br_blockcount, &i);
if (error)
return error;
XFS_WANT_CORRUPTED_GOTO(i == 1, out_error);
got.br_startoff = startoff;
error = xfs_bmbt_update(cur, got.br_startoff, got.br_startblock,
got.br_blockcount, got.br_state);
if (error)
return error;
return 0;
out_error:
return error;
}
/*
* Shift extent records to the left to cover a hole.
*
* The maximum number of extents to be shifted in a single operation
* is @num_exts, and @current_ext keeps track of the current extent
* index we have shifted. @offset_shift_fsb is the length by which each
* extent is shifted. If there is no hole to shift the extents
* into, this will be considered invalid operation and we abort immediately.
* The maximum number of extents to be shifted in a single operation is
* @num_exts. @start_fsb specifies the file offset to start the shift and the
* file offset where we've left off is returned in @next_fsb. @offset_shift_fsb
* is the length by which each extent is shifted. If there is no hole to shift
* the extents into, this will be considered invalid operation and we abort
* immediately.
*/
int
xfs_bmap_shift_extents(
struct xfs_trans *tp,
struct xfs_inode *ip,
int *done,
xfs_fileoff_t start_fsb,
xfs_fileoff_t offset_shift_fsb,
xfs_extnum_t *current_ext,
int *done,
xfs_fileoff_t *next_fsb,
xfs_fsblock_t *firstblock,
struct xfs_bmap_free *flist,
int num_exts)
@@ -5427,16 +5628,13 @@ xfs_bmap_shift_extents(
struct xfs_btree_cur *cur = NULL;
struct xfs_bmbt_rec_host *gotp;
struct xfs_bmbt_irec got;
struct xfs_bmbt_irec left;
struct xfs_mount *mp = ip->i_mount;
struct xfs_ifork *ifp;
xfs_extnum_t nexts = 0;
xfs_fileoff_t startoff;
xfs_extnum_t current_ext;
int error = 0;
int i;
int whichfork = XFS_DATA_FORK;
int logflags = 0;
xfs_filblks_t blockcount = 0;
int total_extents;
if (unlikely(XFS_TEST_ERROR(
@@ -5451,7 +5649,8 @@ xfs_bmap_shift_extents(
if (XFS_FORCED_SHUTDOWN(mp))
return -EIO;
ASSERT(current_ext != NULL);
ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
ifp = XFS_IFORK_PTR(ip, whichfork);
if (!(ifp->if_flags & XFS_IFEXTENTS)) {
@@ -5461,23 +5660,6 @@ xfs_bmap_shift_extents(
return error;
}
/*
* If *current_ext is 0, we would need to lookup the extent
* from where we would start shifting and store it in gotp.
*/
if (!*current_ext) {
gotp = xfs_iext_bno_to_ext(ifp, start_fsb, current_ext);
/*
* gotp can be null in 2 cases: 1) if there are no extents
* or 2) start_fsb lies in a hole beyond which there are
* no extents. Either way, we are done.
*/
if (!gotp) {
*done = 1;
return 0;
}
}
if (ifp->if_flags & XFS_IFBROOT) {
cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
cur->bc_private.b.firstblock = *firstblock;
@@ -5485,113 +5667,47 @@ xfs_bmap_shift_extents(
cur->bc_private.b.flags = 0;
}
/*
* Look up the extent index for the fsb where we start shifting. We can
* henceforth iterate with current_ext as extent list changes are locked
* out via ilock.
*
* gotp can be null in 2 cases: 1) if there are no extents or 2)
* start_fsb lies in a hole beyond which there are no extents. Either
* way, we are done.
*/
gotp = xfs_iext_bno_to_ext(ifp, start_fsb, &current_ext);
if (!gotp) {
*done = 1;
goto del_cursor;
}
/*
* There may be delalloc extents in the data fork before the range we
* are collapsing out, so we cannot
* use the count of real extents here. Instead we have to calculate it
* from the incore fork.
* are collapsing out, so we cannot use the count of real extents here.
* Instead we have to calculate it from the incore fork.
*/
total_extents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
while (nexts++ < num_exts && *current_ext < total_extents) {
gotp = xfs_iext_get_ext(ifp, *current_ext);
xfs_bmbt_get_all(gotp, &got);
startoff = got.br_startoff - offset_shift_fsb;
/*
* Before shifting extent into hole, make sure that the hole
* is large enough to accomodate the shift.
*/
if (*current_ext) {
xfs_bmbt_get_all(xfs_iext_get_ext(ifp,
*current_ext - 1), &left);
if (startoff < left.br_startoff + left.br_blockcount)
error = -EINVAL;
} else if (offset_shift_fsb > got.br_startoff) {
/*
* When first extent is shifted, offset_shift_fsb
* should be less than the stating offset of
* the first extent.
*/
error = -EINVAL;
}
while (nexts++ < num_exts && current_ext < total_extents) {
error = xfs_bmse_shift_one(ip, whichfork, offset_shift_fsb,
&current_ext, gotp, cur, &logflags);
if (error)
goto del_cursor;
if (cur) {
error = xfs_bmbt_lookup_eq(cur, got.br_startoff,
got.br_startblock,
got.br_blockcount,
&i);
if (error)
goto del_cursor;
XFS_WANT_CORRUPTED_GOTO(i == 1, del_cursor);
}
/* Check if we can merge 2 adjacent extents */
if (*current_ext &&
left.br_startoff + left.br_blockcount == startoff &&
left.br_startblock + left.br_blockcount ==
got.br_startblock &&
left.br_state == got.br_state &&
left.br_blockcount + got.br_blockcount <= MAXEXTLEN) {
blockcount = left.br_blockcount +
got.br_blockcount;
xfs_iext_remove(ip, *current_ext, 1, 0);
logflags |= XFS_ILOG_CORE;
if (cur) {
error = xfs_btree_delete(cur, &i);
if (error)
goto del_cursor;
XFS_WANT_CORRUPTED_GOTO(i == 1, del_cursor);
} else {
logflags |= XFS_ILOG_DEXT;
}
XFS_IFORK_NEXT_SET(ip, whichfork,
XFS_IFORK_NEXTENTS(ip, whichfork) - 1);
gotp = xfs_iext_get_ext(ifp, --*current_ext);
xfs_bmbt_get_all(gotp, &got);
/* Make cursor point to the extent we will update */
if (cur) {
error = xfs_bmbt_lookup_eq(cur, got.br_startoff,
got.br_startblock,
got.br_blockcount,
&i);
if (error)
goto del_cursor;
XFS_WANT_CORRUPTED_GOTO(i == 1, del_cursor);
}
xfs_bmbt_set_blockcount(gotp, blockcount);
got.br_blockcount = blockcount;
} else {
/* We have to update the startoff */
xfs_bmbt_set_startoff(gotp, startoff);
got.br_startoff = startoff;
}
logflags |= XFS_ILOG_CORE;
if (cur) {
error = xfs_bmbt_update(cur, got.br_startoff,
got.br_startblock,
got.br_blockcount,
got.br_state);
if (error)
goto del_cursor;
} else {
logflags |= XFS_ILOG_DEXT;
}
(*current_ext)++;
/* update total extent count and grab the next record */
total_extents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
if (current_ext >= total_extents)
break;
gotp = xfs_iext_get_ext(ifp, current_ext);
}
/* Check if we are done */
if (*current_ext == total_extents)
if (current_ext == total_extents) {
*done = 1;
} else if (next_fsb) {
xfs_bmbt_get_all(gotp, &got);
*next_fsb = got.br_startoff;
}
del_cursor:
if (cur)
@@ -5600,5 +5716,6 @@ del_cursor:
if (logflags)
xfs_trans_log_inode(tp, ip, logflags);
return error;
}

7
fs/xfs/libxfs/xfs_bmap.h
View File

@@ -178,9 +178,8 @@ int xfs_check_nostate_extents(struct xfs_ifork *ifp, xfs_extnum_t idx,
xfs_extnum_t num);
uint xfs_default_attroffset(struct xfs_inode *ip);
int xfs_bmap_shift_extents(struct xfs_trans *tp, struct xfs_inode *ip,
int *done, xfs_fileoff_t start_fsb,
xfs_fileoff_t offset_shift_fsb, xfs_extnum_t *current_ext,
xfs_fsblock_t *firstblock, struct xfs_bmap_free *flist,
int num_exts);
xfs_fileoff_t start_fsb, xfs_fileoff_t offset_shift_fsb,
int *done, xfs_fileoff_t *next_fsb, xfs_fsblock_t *firstblock,
struct xfs_bmap_free *flist, int num_exts);
#endif /* __XFS_BMAP_H__ */