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author | Dave Chinner <david@fromorbit.com> | 2014-09-23 07:51:14 +0200 |
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committer | Dave Chinner <david@fromorbit.com> | 2014-09-23 07:51:14 +0200 |
commit | f6d31f4b0462898896ba68e491662958ce37d095 (patch) | |
tree | 6655823e16402769f61fc20edb730b9c7c84a82a /fs/xfs/libxfs | |
parent | Merge branch 'xfs-misc-fixes-for-3.18-1' into for-next (diff) | |
parent | xfs: only writeback and truncate pages for the freed range (diff) | |
download | linux-f6d31f4b0462898896ba68e491662958ce37d095.tar.xz linux-f6d31f4b0462898896ba68e491662958ce37d095.zip |
Merge branch 'xfs-shift-extents-rework' into for-next
Diffstat (limited to 'fs/xfs/libxfs')
-rw-r--r-- | fs/xfs/libxfs/xfs_bmap.c | 365 | ||||
-rw-r--r-- | fs/xfs/libxfs/xfs_bmap.h | 7 |
2 files changed, 244 insertions, 128 deletions
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 86df952d3e24..79c981984dca 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -5404,22 +5404,223 @@ error0: } /* + * 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; @@ -5486,112 +5668,46 @@ xfs_bmap_shift_extents( } /* + * 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, ¤t_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, + ¤t_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; } diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h index b879ca56a64c..44db6db86402 100644 --- a/fs/xfs/libxfs/xfs_bmap.h +++ b/fs/xfs/libxfs/xfs_bmap.h @@ -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__ */ |