Author: mm
Date: Thu Jun 3 11:08:46 2010
New Revision: 208775
URL: http://svn.freebsd.org/changeset/base/208775
Log:
Fix freeing space after deleting large files with holes.
OpenSolaris onnv revision: 9950:78fc41aa9bc5
Approved by: pjd, delphij (mentor)
Obtained from: OpenSolaris (Bug ID 6792701)
MFC after: 3 days
Modified:
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c Thu Jun 3
10:24:53 2010 (r208774)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c Thu Jun 3
11:08:46 2010 (r208775)
@@ -371,56 +371,51 @@ dmu_prefetch(objset_t *os, uint64_t obje
dnode_rele(dn, FTAG);
}
+/*
+ * Get the next "chunk" of file data to free. We traverse the file from
+ * the end so that the file gets shorter over time (if we crashes in the
+ * middle, this will leave us in a better state). We find allocated file
+ * data by simply searching the allocated level 1 indirects.
+ */
static int
-get_next_chunk(dnode_t *dn, uint64_t *offset, uint64_t limit)
+get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t limit)
{
- uint64_t len = *offset - limit;
- uint64_t chunk_len = dn->dn_datablksz * DMU_MAX_DELETEBLKCNT;
- uint64_t subchunk =
+ uint64_t len = *start - limit;
+ uint64_t blkcnt = 0;
+ uint64_t maxblks = DMU_MAX_ACCESS / (1ULL << (dn->dn_indblkshift + 1));
+ uint64_t iblkrange =
dn->dn_datablksz * EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT);
- ASSERT(limit <= *offset);
+ ASSERT(limit <= *start);
- if (len <= chunk_len) {
- *offset = limit;
+ if (len <= iblkrange * maxblks) {
+ *start = limit;
return (0);
}
+ ASSERT(ISP2(iblkrange));
- ASSERT(ISP2(subchunk));
-
- while (*offset > limit) {
- uint64_t initial_offset = P2ROUNDUP(*offset, subchunk);
- uint64_t delta;
+ while (*start > limit && blkcnt < maxblks) {
int err;
- /* skip over allocated data */
+ /* find next allocated L1 indirect */
err = dnode_next_offset(dn,
- DNODE_FIND_HOLE|DNODE_FIND_BACKWARDS, offset, 1, 1, 0);
- if (err == ESRCH)
- *offset = limit;
- else if (err)
- return (err);
+ DNODE_FIND_BACKWARDS, start, 2, 1, 0);
- ASSERT3U(*offset, <=, initial_offset);
- *offset = P2ALIGN(*offset, subchunk);
- delta = initial_offset - *offset;
- if (delta >= chunk_len) {
- *offset += delta - chunk_len;
+ /* if there are no more, then we are done */
+ if (err == ESRCH) {
+ *start = limit;
return (0);
- }
- chunk_len -= delta;
-
- /* skip over unallocated data */
- err = dnode_next_offset(dn,
- DNODE_FIND_BACKWARDS, offset, 1, 1, 0);
- if (err == ESRCH)
- *offset = limit;
- else if (err)
+ } else if (err) {
return (err);
+ }
+ blkcnt += 1;
- if (*offset < limit)
- *offset = limit;
- ASSERT3U(*offset, <, initial_offset);
+ /* reset offset to end of "next" block back */
+ *start = P2ALIGN(*start, iblkrange);
+ if (*start <= limit)
+ *start = limit;
+ else
+ *start -= 1;
}
return (0);
}
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c Thu Jun 3
10:24:53 2010 (r208774)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dnode.c Thu Jun 3
11:08:46 2010 (r208775)
@@ -1239,6 +1239,22 @@ dnode_willuse_space(dnode_t *dn, int64_t
dmu_tx_willuse_space(tx, space);
}
+/*
+ * This function scans a block at the indicated "level" looking for
+ * a hole or data (depending on 'flags'). If level > 0, then we are
+ * scanning an indirect block looking at its pointers. If level == 0,
+ * then we are looking at a block of dnodes. If we don't find what we
+ * are looking for in the block, we return ESRCH. Otherwise, return
+ * with *offset pointing to the beginning (if searching forwards) or
+ * end (if searching backwards) of the range covered by the block
+ * pointer we matched on (or dnode).
+ *
+ * The basic search algorithm used below by dnode_next_offset() is to
+ * use this function to search up the block tree (widen the search) until
+ * we find something (i.e., we don't return ESRCH) and then search back
+ * down the tree (narrow the search) until we reach our original search
+ * level.
+ */
static int
dnode_next_offset_level(dnode_t *dn, int flags, uint64_t *offset,
int lvl, uint64_t blkfill, uint64_t txg)
@@ -1318,6 +1334,7 @@ dnode_next_offset_level(dnode_t *dn, int
error = ESRCH;
} else {
blkptr_t *bp = data;
+ uint64_t start = *offset;
span = (lvl - 1) * epbs + dn->dn_datablkshift;
minfill = 0;
maxfill = blkfill << ((lvl - 1) * epbs);
@@ -1327,18 +1344,25 @@ dnode_next_offset_level(dnode_t *dn, int
else
minfill++;
- for (i = (*offset >> span) & ((1ULL << epbs) - 1);
+ *offset = *offset >> span;
+ for (i = BF64_GET(*offset, 0, epbs);
i >= 0 && i < epb; i += inc) {
if (bp[i].blk_fill >= minfill &&
bp[i].blk_fill <= maxfill &&
(hole || bp[i].blk_birth > txg))
break;
- if (inc < 0 && *offset < (1ULL << span))
- *offset = 0;
- else
- *offset += (1ULL << span) * inc;
+ if (inc > 0 || *offset > 0)
+ *offset += inc;
+ }
+ *offset = *offset << span;
+ if (inc < 0) {
+ /* traversing backwards; position offset at the end */
+ ASSERT3U(*offset, <=, start);
+ *offset = MIN(*offset + (1ULL << span) - 1, start);
+ } else if (*offset < start) {
+ *offset = start;
}
- if (i < 0 || i == epb)
+ if (i < 0 || i >= epb)
error = ESRCH;
}
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