/*
* Dangling inodes can occur if processes are holding open descriptors on
* deleted files as-of when a machine crashes. When we find one simply
* acquire the inode and release it. The inode handling code will then
* do the right thing.
*/
static
void
prune_check_nlinks(hammer_cursor_t cursor, hammer_btree_leaf_elm_t elm)
{
hammer_inode_t ip;
int error;
if (elm->base.rec_type != HAMMER_RECTYPE_INODE)
return;
if (elm->base.delete_tid != 0)
return;
if (hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA))
return;
if (cursor->data->inode.nlinks)
return;
hammer_cursor_downgrade(cursor);
ip = hammer_get_inode(cursor->trans, NULL, elm->base.obj_id,
HAMMER_MAX_TID,
elm->base.localization & HAMMER_LOCALIZE_PSEUDOFS_MASK,
0, &error);
if (ip) {
if (hammer_debug_general & 0x0001) {
kprintf("pruning disconnected inode %016llx\n",
(long long)elm->base.obj_id);
}
hammer_rel_inode(ip, 0);
hammer_inode_waitreclaims(cursor->trans);
} else {
kprintf("unable to prune disconnected inode %016llx\n",
(long long)elm->base.obj_id);
}
}
/*
* Reblock a record's data. Both the B-Tree element and record pointers
* to the data must be adjusted.
*/
static int
hammer_reblock_data(struct hammer_ioc_reblock *reblock,
hammer_cursor_t cursor, hammer_btree_elm_t elm)
{
struct hammer_buffer *data_buffer = NULL;
hammer_off_t ndata_offset;
int error;
void *ndata;
error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
HAMMER_CURSOR_GET_LEAF);
if (error)
return (error);
ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len,
elm->leaf.base.rec_type,
&ndata_offset, &data_buffer,
0, &error);
if (error)
goto done;
hammer_io_notmeta(data_buffer);
/*
* Move the data. Note that we must invalidate any cached
* data buffer in the cursor before calling blockmap_free.
* The blockmap_free may free up the entire large-block and
* will not be able to invalidate it if the cursor is holding
* a data buffer cached in that large block.
*/
hammer_modify_buffer(cursor->trans, data_buffer, NULL, 0);
bcopy(cursor->data, ndata, elm->leaf.data_len);
hammer_modify_buffer_done(data_buffer);
hammer_cursor_invalidate_cache(cursor);
hammer_blockmap_free(cursor->trans,
elm->leaf.data_offset, elm->leaf.data_len);
hammer_modify_node(cursor->trans, cursor->node,
&elm->leaf.data_offset, sizeof(hammer_off_t));
elm->leaf.data_offset = ndata_offset;
hammer_modify_node_done(cursor->node);
done:
if (data_buffer)
hammer_rel_buffer(data_buffer, 0);
return (error);
}
/*
* Reblock a record's data. Both the B-Tree element and record pointers
* to the data must be adjusted.
*/
static int
hammer_reblock_data(struct hammer_ioc_reblock *reblock,
hammer_cursor_t cursor, hammer_btree_elm_t elm)
{
struct hammer_buffer *data_buffer = NULL;
hammer_off_t ndata_offset;
int error;
void *ndata;
error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
HAMMER_CURSOR_GET_LEAF);
if (error)
return (error);
ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len,
elm->leaf.base.rec_type,
&ndata_offset, &data_buffer, &error);
if (error)
goto done;
/*
* Move the data
*/
hammer_modify_buffer(cursor->trans, data_buffer, NULL, 0);
bcopy(cursor->data, ndata, elm->leaf.data_len);
hammer_modify_buffer_done(data_buffer);
hammer_blockmap_free(cursor->trans,
elm->leaf.data_offset, elm->leaf.data_len);
hammer_modify_node(cursor->trans, cursor->node,
&elm->leaf.data_offset, sizeof(hammer_off_t));
elm->leaf.data_offset = ndata_offset;
hammer_modify_node_done(cursor->node);
done:
if (data_buffer)
hammer_rel_buffer(data_buffer, 0);
return (error);
}
/*
* All B-Tree records within the specified key range which also conform
* to the transaction id range are returned. Mirroring code keeps track
* of the last transaction id fully scanned and can efficiently pick up
* where it left off if interrupted.
*
* The PFS is identified in the mirror structure. The passed ip is just
* some directory in the overall HAMMER filesystem and has nothing to
* do with the PFS.
*/
int
hammer_ioc_mirror_read(hammer_transaction_t trans, hammer_inode_t ip,
struct hammer_ioc_mirror_rw *mirror)
{
struct hammer_cmirror cmirror;
struct hammer_cursor cursor;
union hammer_ioc_mrecord_any mrec;
hammer_btree_leaf_elm_t elm;
const int crc_start = HAMMER_MREC_CRCOFF;
char *uptr;
int error;
int data_len;
int bytes;
int eatdisk;
int mrec_flags;
u_int32_t localization;
u_int32_t rec_crc;
localization = (u_int32_t)mirror->pfs_id << 16;
if ((mirror->key_beg.localization | mirror->key_end.localization) &
HAMMER_LOCALIZE_PSEUDOFS_MASK) {
return(EINVAL);
}
if (hammer_btree_cmp(&mirror->key_beg, &mirror->key_end) > 0)
return(EINVAL);
mirror->key_cur = mirror->key_beg;
mirror->key_cur.localization &= HAMMER_LOCALIZE_MASK;
mirror->key_cur.localization += localization;
bzero(&mrec, sizeof(mrec));
bzero(&cmirror, sizeof(cmirror));
/*
* Make CRC errors non-fatal (at least on data), causing an EDOM
* error instead of EIO.
*/
trans->flags |= HAMMER_TRANSF_CRCDOM;
retry:
error = hammer_init_cursor(trans, &cursor, NULL, NULL);
if (error) {
hammer_done_cursor(&cursor);
goto failed;
}
cursor.key_beg = mirror->key_cur;
cursor.key_end = mirror->key_end;
cursor.key_end.localization &= HAMMER_LOCALIZE_MASK;
cursor.key_end.localization += localization;
cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE;
cursor.flags |= HAMMER_CURSOR_BACKEND;
/*
* This flag filters the search to only return elements whos create
* or delete TID is >= mirror_tid. The B-Tree uses the mirror_tid
* field stored with internal and leaf nodes to shortcut the scan.
*/
cursor.flags |= HAMMER_CURSOR_MIRROR_FILTERED;
cursor.cmirror = &cmirror;
cmirror.mirror_tid = mirror->tid_beg;
error = hammer_btree_first(&cursor);
while (error == 0) {
/*
* Yield to more important tasks
*/
if (error == 0) {
error = hammer_signal_check(trans->hmp);
if (error)
break;
}
/*
* An internal node can be returned in mirror-filtered
* mode and indicates that the scan is returning a skip
* range in the cursor->cmirror structure.
*/
uptr = (char *)mirror->ubuf + mirror->count;
if (cursor.node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) {
/*
* Check space
*/
mirror->key_cur = cmirror.skip_beg;
bytes = sizeof(mrec.skip);
if (mirror->count + HAMMER_HEAD_DOALIGN(bytes) >
mirror->size) {
break;
}
/*
* Fill mrec
*/
mrec.head.signature = HAMMER_IOC_MIRROR_SIGNATURE;
mrec.head.type = HAMMER_MREC_TYPE_SKIP;
mrec.head.rec_size = bytes;
mrec.skip.skip_beg = cmirror.skip_beg;
mrec.skip.skip_end = cmirror.skip_end;
mrec.head.rec_crc = crc32(&mrec.head.rec_size,
bytes - crc_start);
error = copyout(&mrec, uptr, bytes);
eatdisk = 0;
goto didwrite;
}
/*
* Leaf node. In full-history mode we could filter out
* elements modified outside the user-requested TID range.
*
* However, such elements must be returned so the writer
* can compare them against the target to determine what
* needs to be deleted on the target, particular for
* no-history mirrors.
*/
KKASSERT(cursor.node->ondisk->type == HAMMER_BTREE_TYPE_LEAF);
elm = &cursor.node->ondisk->elms[cursor.index].leaf;
mirror->key_cur = elm->base;
/*
* If the record was created after our end point we just
* ignore it.
*/
if (elm->base.create_tid > mirror->tid_end) {
error = 0;
bytes = 0;
eatdisk = 1;
goto didwrite;
}
/*
* Determine if we should generate a PASS or a REC. PASS
* records are records without any data payload. Such
* records will be generated if the target is already expected
* to have the record, allowing it to delete the gaps.
*
* A PASS record is also used to perform deletions on the
* target.
*
* Such deletions are needed if the master or files on the
* master are no-history, or if the slave is so far behind
* the master has already been pruned.
*/
if (elm->base.create_tid < mirror->tid_beg) {
bytes = sizeof(mrec.rec);
if (mirror->count + HAMMER_HEAD_DOALIGN(bytes) >
mirror->size) {
break;
}
/*
* Fill mrec.
*/
mrec.head.signature = HAMMER_IOC_MIRROR_SIGNATURE;
mrec.head.type = HAMMER_MREC_TYPE_PASS;
mrec.head.rec_size = bytes;
mrec.rec.leaf = *elm;
mrec.head.rec_crc = crc32(&mrec.head.rec_size,
bytes - crc_start);
error = copyout(&mrec, uptr, bytes);
eatdisk = 1;
goto didwrite;
}
/*
* The core code exports the data to userland.
*
* CRC errors on data are reported but passed through,
* but the data must be washed by the user program.
*
* If userland just wants the btree records it can
* request that bulk data not be returned. This is
* use during mirror-stream histogram generation.
*/
mrec_flags = 0;
data_len = (elm->data_offset) ? elm->data_len : 0;
if (data_len &&
(mirror->head.flags & HAMMER_IOC_MIRROR_NODATA)) {
data_len = 0;
mrec_flags |= HAMMER_MRECF_NODATA;
}
if (data_len) {
error = hammer_btree_extract(&cursor,
HAMMER_CURSOR_GET_DATA);
if (error) {
if (error != EDOM)
break;
mrec_flags |= HAMMER_MRECF_CRC_ERROR |
HAMMER_MRECF_DATA_CRC_BAD;
}
}
bytes = sizeof(mrec.rec) + data_len;
if (mirror->count + HAMMER_HEAD_DOALIGN(bytes) > mirror->size)
break;
/*
* Construct the record for userland and copyout.
*
* The user is asking for a snapshot, if the record was
* deleted beyond the user-requested ending tid, the record
* is not considered deleted from the point of view of
* userland and delete_tid is cleared.
*/
mrec.head.signature = HAMMER_IOC_MIRROR_SIGNATURE;
mrec.head.type = HAMMER_MREC_TYPE_REC | mrec_flags;
mrec.head.rec_size = bytes;
mrec.rec.leaf = *elm;
if (elm->base.delete_tid > mirror->tid_end)
mrec.rec.leaf.base.delete_tid = 0;
rec_crc = crc32(&mrec.head.rec_size,
sizeof(mrec.rec) - crc_start);
if (data_len)
rec_crc = crc32_ext(cursor.data, data_len, rec_crc);
mrec.head.rec_crc = rec_crc;
error = copyout(&mrec, uptr, sizeof(mrec.rec));
if (data_len && error == 0) {
error = copyout(cursor.data, uptr + sizeof(mrec.rec),
data_len);
}
eatdisk = 1;
/*
* eatdisk controls whether we skip the current cursor
* position on the next scan or not. If doing a SKIP
* the cursor is already positioned properly for the next
* scan and eatdisk will be 0.
*/
didwrite:
if (error == 0) {
mirror->count += HAMMER_HEAD_DOALIGN(bytes);
if (eatdisk)
cursor.flags |= HAMMER_CURSOR_ATEDISK;
else
cursor.flags &= ~HAMMER_CURSOR_ATEDISK;
error = hammer_btree_iterate(&cursor);
}
}
if (error == ENOENT) {
mirror->key_cur = mirror->key_end;
error = 0;
}
hammer_done_cursor(&cursor);
if (error == EDEADLK)
goto retry;
if (error == EINTR) {
mirror->head.flags |= HAMMER_IOC_HEAD_INTR;
error = 0;
}
failed:
mirror->key_cur.localization &= HAMMER_LOCALIZE_MASK;
return(error);
}
/*
* NOTE: THIS CODE HAS BEEN REMOVED! Pruning no longer attempts to realign
* adjacent records because it seriously interferes with every
* mirroring algorithm I could come up with.
*
* This means that historical accesses beyond the first snapshot
* softlink should be on snapshot boundaries only. Historical
* accesses from "now" to the first snapshot softlink continue to
* be fine-grained.
*
* NOTE: It also looks like there's a bug in the removed code. It is believed
* that create_tid can sometimes get set to 0xffffffffffffffff. Just as
* well we no longer try to do this fancy shit. Probably the attempt to
* correct the rhb is blowing up the cursor's indexing or addressing mapping.
*
* Align the record to cover any gaps created through the deletion of
* records within the pruning space. If we were to just delete the records
* there would be gaps which in turn would cause a snapshot that is NOT on
* a pruning boundary to appear corrupt to the user. Forcing alignment
* of the create_tid and delete_tid for retained records 'reconnects'
* the previously contiguous space, making it contiguous again after the
* deletions.
*
* The use of a reverse iteration allows us to safely align the records and
* related elements without creating temporary overlaps. XXX we should
* add ordering dependancies for record buffers to guarantee consistency
* during recovery.
*/
static int
realign_prune(struct hammer_ioc_prune *prune,
hammer_cursor_t cursor, int realign_cre, int realign_del)
{
struct hammer_ioc_prune_elm *scan;
hammer_btree_elm_t elm;
hammer_tid_t delta;
hammer_tid_t tid;
int error;
hammer_cursor_downgrade(cursor);
elm = &cursor->node->ondisk->elms[cursor->index];
++prune->stat_realignments;
/*
* Align the create_tid. By doing a reverse iteration we guarantee
* that all records after our current record have already been
* aligned, allowing us to safely correct the right-hand-boundary
* (because no record to our right is otherwise exactly matching
* will have a create_tid to the left of our aligned create_tid).
*/
error = 0;
if (realign_cre >= 0) {
scan = &prune->elms[realign_cre];
delta = (elm->leaf.base.create_tid - scan->beg_tid) %
scan->mod_tid;
if (delta) {
tid = elm->leaf.base.create_tid - delta + scan->mod_tid;
/* can EDEADLK */
error = hammer_btree_correct_rhb(cursor, tid + 1);
if (error == 0) {
error = hammer_btree_extract(cursor,
HAMMER_CURSOR_GET_LEAF);
}
if (error == 0) {
/* can EDEADLK */
error = hammer_cursor_upgrade(cursor);
}
if (error == 0) {
hammer_modify_node(cursor->trans, cursor->node,
&elm->leaf.base.create_tid,
sizeof(elm->leaf.base.create_tid));
elm->leaf.base.create_tid = tid;
hammer_modify_node_done(cursor->node);
}
}
}
/*
* Align the delete_tid. This only occurs if the record is historical
* was deleted at some point. Realigning the delete_tid does not
* move the record within the B-Tree but may cause it to temporarily
* overlap a record that has not yet been pruned.
*/
if (error == 0 && realign_del >= 0) {
scan = &prune->elms[realign_del];
delta = (elm->leaf.base.delete_tid - scan->beg_tid) %
scan->mod_tid;
if (delta) {
error = hammer_btree_extract(cursor,
HAMMER_CURSOR_GET_LEAF);
if (error == 0) {
hammer_modify_node(cursor->trans, cursor->node,
&elm->leaf.base.delete_tid,
sizeof(elm->leaf.base.delete_tid));
elm->leaf.base.delete_tid =
elm->leaf.base.delete_tid -
delta + scan->mod_tid;
hammer_modify_node_done(cursor->node);
}
}
}
return (error);
}
int
hammer_ioc_dedup(hammer_transaction_t trans, hammer_inode_t ip,
struct hammer_ioc_dedup *dedup)
{
struct hammer_cursor cursor1, cursor2;
int error;
int seq;
/*
* Enforce hammer filesystem version requirements
*/
if (trans->hmp->version < HAMMER_VOL_VERSION_FIVE) {
kprintf("hammer: Filesystem must be upgraded to v5 "
"before you can run dedup\n");
return (EOPNOTSUPP); /* 95*/
}
/*
* Cursor1, return an error -> candidate goes to pass2 list
*/
error = hammer_init_cursor(trans, &cursor1, NULL, NULL);
if (error)
goto done_cursor;
cursor1.key_beg = dedup->elm1;
cursor1.flags |= HAMMER_CURSOR_BACKEND;
error = hammer_btree_lookup(&cursor1);
if (error)
goto done_cursor;
error = hammer_btree_extract(&cursor1, HAMMER_CURSOR_GET_LEAF |
HAMMER_CURSOR_GET_DATA);
if (error)
goto done_cursor;
/*
* Cursor2, return an error -> candidate goes to pass2 list
*/
error = hammer_init_cursor(trans, &cursor2, NULL, NULL);
if (error)
goto done_cursors;
cursor2.key_beg = dedup->elm2;
cursor2.flags |= HAMMER_CURSOR_BACKEND;
error = hammer_btree_lookup(&cursor2);
if (error)
goto done_cursors;
error = hammer_btree_extract(&cursor2, HAMMER_CURSOR_GET_LEAF |
HAMMER_CURSOR_GET_DATA);
if (error)
goto done_cursors;
/*
* Zone validation. We can't de-dup any of the other zones
* (BTREE or META) or bad things will happen.
*
* Return with error = 0, but set an INVALID_ZONE flag.
*/
error = validate_zone(cursor1.leaf->data_offset) +
validate_zone(cursor2.leaf->data_offset);
if (error) {
dedup->head.flags |= HAMMER_IOC_DEDUP_INVALID_ZONE;
error = 0;
goto done_cursors;
}
/*
* Comparison checks
*
* If zones don't match or data_len fields aren't the same
* we consider it to be a comparison failure.
*
* Return with error = 0, but set a CMP_FAILURE flag.
*/
if ((cursor1.leaf->data_offset & HAMMER_OFF_ZONE_MASK) !=
(cursor2.leaf->data_offset & HAMMER_OFF_ZONE_MASK)) {
dedup->head.flags |= HAMMER_IOC_DEDUP_CMP_FAILURE;
goto done_cursors;
}
if (cursor1.leaf->data_len != cursor2.leaf->data_len) {
dedup->head.flags |= HAMMER_IOC_DEDUP_CMP_FAILURE;
goto done_cursors;
}
/* byte-by-byte comparison to be sure */
if (bcmp(cursor1.data, cursor2.data, cursor1.leaf->data_len)) {
dedup->head.flags |= HAMMER_IOC_DEDUP_CMP_FAILURE;
goto done_cursors;
}
/*
* Upgrade both cursors together to an exclusive lock
*
* Return an error -> candidate goes to pass2 list
*/
hammer_sync_lock_sh(trans);
error = hammer_cursor_upgrade2(&cursor1, &cursor2);
if (error) {
hammer_sync_unlock(trans);
goto done_cursors;
}
error = hammer_blockmap_dedup(cursor1.trans,
cursor1.leaf->data_offset, cursor1.leaf->data_len);
if (error) {
if (error == ERANGE) {
/*
* Return with error = 0, but set an UNDERFLOW flag
*/
dedup->head.flags |= HAMMER_IOC_DEDUP_UNDERFLOW;
error = 0;
goto downgrade_cursors;
} else {
/*
* Return an error -> block goes to pass2 list
*/
goto downgrade_cursors;
}
}
/*
* The cursor2's cache must be invalidated before calling
* hammer_blockmap_free(), otherwise it will not be able to
* invalidate the underlying data buffer.
*/
hammer_cursor_invalidate_cache(&cursor2);
hammer_blockmap_free(cursor2.trans,
cursor2.leaf->data_offset, cursor2.leaf->data_len);
hammer_modify_node(cursor2.trans, cursor2.node,
&cursor2.leaf->data_offset, sizeof(hammer_off_t));
cursor2.leaf->data_offset = cursor1.leaf->data_offset;
hammer_modify_node_done(cursor2.node);
downgrade_cursors:
hammer_cursor_downgrade2(&cursor1, &cursor2);
hammer_sync_unlock(trans);
done_cursors:
hammer_done_cursor(&cursor2);
done_cursor:
hammer_done_cursor(&cursor1);
/*
* Avoid deadlocking the buffer cache
*/
seq = trans->hmp->flusher.done;
while (hammer_flusher_meta_halflimit(trans->hmp) ||
hammer_flusher_undo_exhausted(trans, 2)) {
hammer_flusher_wait(trans->hmp, seq);
seq = hammer_flusher_async_one(trans->hmp);
}
return (error);
}
