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xfs: refactor the xrep_extent_list into xfs_bitmap 

As mentioned previously, the xrep_extent_list basically implements a
bitmap with two functions: set and disjoint union.  Rename all these
functions to xfs_bitmap to shorten the name and make it more obvious
what we're doing.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This commit is contained in:
Darrick J. Wong 2018-07-30 11:18:13 -07:00
parent 51d6269030
commit 86d969b425
5 changed files with 149 additions and 163 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

183
fs/xfs/scrub/bitmap.c
View File

@ -16,183 +16,186 @@
#include "scrub/repair.h"
#include "scrub/bitmap.h"
/* Collect a dead btree extent for later disposal. */
/*
* Set a range of this bitmap. Caller must ensure the range is not set.
*
* This is the logical equivalent of bitmap |= mask(start, len).
*/
int
xrep_collect_btree_extent(
struct xfs_scrub *sc,
struct xrep_extent_list *exlist,
xfs_fsblock_t fsbno,
xfs_extlen_t len)
xfs_bitmap_set(
struct xfs_bitmap *bitmap,
uint64_t start,
uint64_t len)
{
struct xrep_extent *rex;
struct xfs_bitmap_range *bmr;
trace_xrep_collect_btree_extent(sc->mp,
XFS_FSB_TO_AGNO(sc->mp, fsbno),
XFS_FSB_TO_AGBNO(sc->mp, fsbno), len);
rex = kmem_alloc(sizeof(struct xrep_extent), KM_MAYFAIL);
if (!rex)
bmr = kmem_alloc(sizeof(struct xfs_bitmap_range), KM_MAYFAIL);
if (!bmr)
return -ENOMEM;
INIT_LIST_HEAD(&rex->list);
rex->fsbno = fsbno;
rex->len = len;
list_add_tail(&rex->list, &exlist->list);
INIT_LIST_HEAD(&bmr->list);
bmr->start = start;
bmr->len = len;
list_add_tail(&bmr->list, &bitmap->list);
return 0;
}
/*
* An error happened during the rebuild so the transaction will be cancelled.
* The fs will shut down, and the administrator has to unmount and run repair.
* Therefore, free all the memory associated with the list so we can die.
*/
/* Free everything related to this bitmap. */
void
xrep_cancel_btree_extents(
struct xfs_scrub *sc,
struct xrep_extent_list *exlist)
xfs_bitmap_destroy(
struct xfs_bitmap *bitmap)
{
struct xrep_extent *rex;
struct xrep_extent *n;
struct xfs_bitmap_range *bmr;
struct xfs_bitmap_range *n;
for_each_xrep_extent_safe(rex, n, exlist) {
list_del(&rex->list);
kmem_free(rex);
for_each_xfs_bitmap_extent(bmr, n, bitmap) {
list_del(&bmr->list);
kmem_free(bmr);
}
}
/* Set up a per-AG block bitmap. */
void
xfs_bitmap_init(
struct xfs_bitmap *bitmap)
{
INIT_LIST_HEAD(&bitmap->list);
}
/* Compare two btree extents. */
static int
xrep_btree_extent_cmp(
xfs_bitmap_range_cmp(
void *priv,
struct list_head *a,
struct list_head *b)
{
struct xrep_extent *ap;
struct xrep_extent *bp;
struct xfs_bitmap_range *ap;
struct xfs_bitmap_range *bp;
ap = container_of(a, struct xrep_extent, list);
bp = container_of(b, struct xrep_extent, list);
ap = container_of(a, struct xfs_bitmap_range, list);
bp = container_of(b, struct xfs_bitmap_range, list);
if (ap->fsbno > bp->fsbno)
if (ap->start > bp->start)
return 1;
if (ap->fsbno < bp->fsbno)
if (ap->start < bp->start)
return -1;
return 0;
}
/*
* Remove all the blocks mentioned in @sublist from the extents in @exlist.
* Remove all the blocks mentioned in @sub from the extents in @bitmap.
*
* The intent is that callers will iterate the rmapbt for all of its records
* for a given owner to generate @exlist; and iterate all the blocks of the
* for a given owner to generate @bitmap; and iterate all the blocks of the
* metadata structures that are not being rebuilt and have the same rmapbt
* owner to generate @sublist. This routine subtracts all the extents
* mentioned in sublist from all the extents linked in @exlist, which leaves
* @exlist as the list of blocks that are not accounted for, which we assume
* owner to generate @sub. This routine subtracts all the extents
* mentioned in sub from all the extents linked in @bitmap, which leaves
* @bitmap as the list of blocks that are not accounted for, which we assume
* are the dead blocks of the old metadata structure. The blocks mentioned in
* @exlist can be reaped.
* @bitmap can be reaped.
*
* This is the logical equivalent of bitmap &= ~sub.
*/
#define LEFT_ALIGNED (1 << 0)
#define RIGHT_ALIGNED (1 << 1)
int
xrep_subtract_extents(
struct xfs_scrub *sc,
struct xrep_extent_list *exlist,
struct xrep_extent_list *sublist)
xfs_bitmap_disunion(
struct xfs_bitmap *bitmap,
struct xfs_bitmap *sub)
{
struct list_head *lp;
struct xrep_extent *ex;
struct xrep_extent *newex;
struct xrep_extent *subex;
xfs_fsblock_t sub_fsb;
xfs_extlen_t sub_len;
struct xfs_bitmap_range *br;
struct xfs_bitmap_range *new_br;
struct xfs_bitmap_range *sub_br;
uint64_t sub_start;
uint64_t sub_len;
int state;
int error = 0;
if (list_empty(&exlist->list) || list_empty(&sublist->list))
if (list_empty(&bitmap->list) || list_empty(&sub->list))
return 0;
ASSERT(!list_empty(&sublist->list));
ASSERT(!list_empty(&sub->list));
list_sort(NULL, &exlist->list, xrep_btree_extent_cmp);
list_sort(NULL, &sublist->list, xrep_btree_extent_cmp);
list_sort(NULL, &bitmap->list, xfs_bitmap_range_cmp);
list_sort(NULL, &sub->list, xfs_bitmap_range_cmp);
/*
* Now that we've sorted both lists, we iterate exlist once, rolling
* forward through sublist and/or exlist as necessary until we find an
* Now that we've sorted both lists, we iterate bitmap once, rolling
* forward through sub and/or bitmap as necessary until we find an
* overlap or reach the end of either list. We do not reset lp to the
* head of exlist nor do we reset subex to the head of sublist. The
* head of bitmap nor do we reset sub_br to the head of sub. The
* list traversal is similar to merge sort, but we're deleting
* instead. In this manner we avoid O(n^2) operations.
*/
subex = list_first_entry(&sublist->list, struct xrep_extent,
sub_br = list_first_entry(&sub->list, struct xfs_bitmap_range,
list);
lp = exlist->list.next;
while (lp != &exlist->list) {
ex = list_entry(lp, struct xrep_extent, list);
lp = bitmap->list.next;
while (lp != &bitmap->list) {
br = list_entry(lp, struct xfs_bitmap_range, list);
/*
* Advance subex and/or ex until we find a pair that
* Advance sub_br and/or br until we find a pair that
* intersect or we run out of extents.
*/
while (subex->fsbno + subex->len <= ex->fsbno) {
if (list_is_last(&subex->list, &sublist->list))
while (sub_br->start + sub_br->len <= br->start) {
if (list_is_last(&sub_br->list, &sub->list))
goto out;
subex = list_next_entry(subex, list);
sub_br = list_next_entry(sub_br, list);
}
if (subex->fsbno >= ex->fsbno + ex->len) {
if (sub_br->start >= br->start + br->len) {
lp = lp->next;
continue;
}
/* trim subex to fit the extent we have */
sub_fsb = subex->fsbno;
sub_len = subex->len;
if (subex->fsbno < ex->fsbno) {
sub_len -= ex->fsbno - subex->fsbno;
sub_fsb = ex->fsbno;
/* trim sub_br to fit the extent we have */
sub_start = sub_br->start;
sub_len = sub_br->len;
if (sub_br->start < br->start) {
sub_len -= br->start - sub_br->start;
sub_start = br->start;
}
if (sub_len > ex->len)
sub_len = ex->len;
if (sub_len > br->len)
sub_len = br->len;
state = 0;
if (sub_fsb == ex->fsbno)
if (sub_start == br->start)
state |= LEFT_ALIGNED;
if (sub_fsb + sub_len == ex->fsbno + ex->len)
if (sub_start + sub_len == br->start + br->len)
state |= RIGHT_ALIGNED;
switch (state) {
case LEFT_ALIGNED:
/* Coincides with only the left. */
ex->fsbno += sub_len;
ex->len -= sub_len;
br->start += sub_len;
br->len -= sub_len;
break;
case RIGHT_ALIGNED:
/* Coincides with only the right. */
ex->len -= sub_len;
br->len -= sub_len;
lp = lp->next;
break;
case LEFT_ALIGNED | RIGHT_ALIGNED:
/* Total overlap, just delete ex. */
lp = lp->next;
list_del(&ex->list);
kmem_free(ex);
list_del(&br->list);
kmem_free(br);
break;
case 0:
/*
* Deleting from the middle: add the new right extent
* and then shrink the left extent.
*/
newex = kmem_alloc(sizeof(struct xrep_extent),
new_br = kmem_alloc(sizeof(struct xfs_bitmap_range),
KM_MAYFAIL);
if (!newex) {
if (!new_br) {
error = -ENOMEM;
goto out;
}
INIT_LIST_HEAD(&newex->list);
newex->fsbno = sub_fsb + sub_len;
newex->len = ex->fsbno + ex->len - newex->fsbno;
list_add(&newex->list, &ex->list);
ex->len = sub_fsb - ex->fsbno;
INIT_LIST_HEAD(&new_br->list);
new_br->start = sub_start + sub_len;
new_br->len = br->start + br->len - new_br->start;
list_add(&new_br->list, &br->list);
br->len = sub_start - br->start;
lp = lp->next;
break;
default:

35
fs/xfs/scrub/bitmap.h
View File

@ -6,32 +6,27 @@
#ifndef __XFS_SCRUB_BITMAP_H__
#define __XFS_SCRUB_BITMAP_H__
struct xrep_extent {
struct xfs_bitmap_range {
struct list_head list;
xfs_fsblock_t fsbno;
xfs_extlen_t len;
uint64_t start;
uint64_t len;
};
struct xrep_extent_list {
struct xfs_bitmap {
struct list_head list;
};
static inline void
xrep_init_extent_list(
struct xrep_extent_list *exlist)
{
INIT_LIST_HEAD(&exlist->list);
}
void xfs_bitmap_init(struct xfs_bitmap *bitmap);
void xfs_bitmap_destroy(struct xfs_bitmap *bitmap);
#define for_each_xrep_extent_safe(rbe, n, exlist) \
list_for_each_entry_safe((rbe), (n), &(exlist)->list, list)
int xrep_collect_btree_extent(struct xfs_scrub *sc,
struct xrep_extent_list *btlist, xfs_fsblock_t fsbno,
xfs_extlen_t len);
void xrep_cancel_btree_extents(struct xfs_scrub *sc,
struct xrep_extent_list *btlist);
int xrep_subtract_extents(struct xfs_scrub *sc,
struct xrep_extent_list *exlist,
struct xrep_extent_list *sublist);
#define for_each_xfs_bitmap_extent(bex, n, bitmap) \
list_for_each_entry_safe((bex), (n), &(bitmap)->list, list)
#define for_each_xfs_bitmap_block(b, bex, n, bitmap) \
list_for_each_entry_safe((bex), (n), &(bitmap)->list, list) \
for ((b) = bex->start; (b) < bex->start + bex->len; (b)++)
int xfs_bitmap_set(struct xfs_bitmap *bitmap, uint64_t start, uint64_t len);
int xfs_bitmap_disunion(struct xfs_bitmap *bitmap, struct xfs_bitmap *sub);
#endif /* __XFS_SCRUB_BITMAP_H__ */

85
fs/xfs/scrub/repair.c
View File

@ -368,17 +368,17 @@ xrep_init_btblock(
*
* However, that leaves the matter of removing all the metadata describing the
* old broken structure. For primary metadata we use the rmap data to collect
* every extent with a matching rmap owner (exlist); we then iterate all other
* every extent with a matching rmap owner (bitmap); we then iterate all other
* metadata structures with the same rmap owner to collect the extents that
* cannot be removed (sublist). We then subtract sublist from exlist to
* cannot be removed (sublist). We then subtract sublist from bitmap to
* derive the blocks that were used by the old btree. These blocks can be
* reaped.
*
* For rmapbt reconstructions we must use different tactics for extent
* collection. First we iterate all primary metadata (this excludes the old
* rmapbt, obviously) to generate new rmap records. The gaps in the rmap
* records are collected as exlist. The bnobt records are collected as
* sublist. As with the other btrees we subtract sublist from exlist, and the
* records are collected as bitmap. The bnobt records are collected as
* sublist. As with the other btrees we subtract sublist from bitmap, and the
* result (since the rmapbt lives in the free space) are the blocks from the
* old rmapbt.
*
@ -386,11 +386,11 @@ xrep_init_btblock(
*
* Now that we've constructed a new btree to replace the damaged one, we want
* to dispose of the blocks that (we think) the old btree was using.
* Previously, we used the rmapbt to collect the extents (exlist) with the
* Previously, we used the rmapbt to collect the extents (bitmap) with the
* rmap owner corresponding to the tree we rebuilt, collected extents for any
* blocks with the same rmap owner that are owned by another data structure
* (sublist), and subtracted sublist from exlist. In theory the extents
* remaining in exlist are the old btree's blocks.
* (sublist), and subtracted sublist from bitmap. In theory the extents
* remaining in bitmap are the old btree's blocks.
*
* Unfortunately, it's possible that the btree was crosslinked with other
* blocks on disk. The rmap data can tell us if there are multiple owners, so
@ -406,7 +406,7 @@ xrep_init_btblock(
* If there are no rmap records at all, we also free the block. If the btree
* being rebuilt lives in the free space (bnobt/cntbt/rmapbt) then there isn't
* supposed to be a rmap record and everything is ok. For other btrees there
* had to have been an rmap entry for the block to have ended up on @exlist,
* had to have been an rmap entry for the block to have ended up on @bitmap,
* so if it's gone now there's something wrong and the fs will shut down.
*
* Note: If there are multiple rmap records with only the same rmap owner as
@ -419,7 +419,7 @@ xrep_init_btblock(
* The caller is responsible for locking the AG headers for the entire rebuild
* operation so that nothing else can sneak in and change the AG state while
* we're not looking. We also assume that the caller already invalidated any
* buffers associated with @exlist.
* buffers associated with @bitmap.
*/
/*
@ -429,13 +429,12 @@ xrep_init_btblock(
int
xrep_invalidate_blocks(
struct xfs_scrub *sc,
struct xrep_extent_list *exlist)
struct xfs_bitmap *bitmap)
{
struct xrep_extent *rex;
struct xrep_extent *n;
struct xfs_bitmap_range *bmr;
struct xfs_bitmap_range *n;
struct xfs_buf *bp;
xfs_fsblock_t fsbno;
xfs_agblock_t i;
/*
* For each block in each extent, see if there's an incore buffer for
@ -445,18 +444,16 @@ xrep_invalidate_blocks(
* because we never own those; and if we can't TRYLOCK the buffer we
* assume it's owned by someone else.
*/
for_each_xrep_extent_safe(rex, n, exlist) {
for (fsbno = rex->fsbno, i = rex->len; i > 0; fsbno++, i--) {
/* Skip AG headers and post-EOFS blocks */
if (!xfs_verify_fsbno(sc->mp, fsbno))
continue;
bp = xfs_buf_incore(sc->mp->m_ddev_targp,
XFS_FSB_TO_DADDR(sc->mp, fsbno),
XFS_FSB_TO_BB(sc->mp, 1), XBF_TRYLOCK);
if (bp) {
xfs_trans_bjoin(sc->tp, bp);
xfs_trans_binval(sc->tp, bp);
}
for_each_xfs_bitmap_block(fsbno, bmr, n, bitmap) {
/* Skip AG headers and post-EOFS blocks */
if (!xfs_verify_fsbno(sc->mp, fsbno))
continue;
bp = xfs_buf_incore(sc->mp->m_ddev_targp,
XFS_FSB_TO_DADDR(sc->mp, fsbno),
XFS_FSB_TO_BB(sc->mp, 1), XBF_TRYLOCK);
if (bp) {
xfs_trans_bjoin(sc->tp, bp);
xfs_trans_binval(sc->tp, bp);
}
}
@ -519,9 +516,9 @@ xrep_put_freelist(
return 0;
}
/* Dispose of a single metadata block. */
/* Dispose of a single block. */
STATIC int
xrep_dispose_btree_block(
xrep_reap_block(
struct xfs_scrub *sc,
xfs_fsblock_t fsbno,
struct xfs_owner_info *oinfo,
@ -593,41 +590,35 @@ out_free:
return error;
}
/* Dispose of btree blocks from an old per-AG btree. */
/* Dispose of every block of every extent in the bitmap. */
int
xrep_reap_btree_extents(
xrep_reap_extents(
struct xfs_scrub *sc,
struct xrep_extent_list *exlist,
struct xfs_bitmap *bitmap,
struct xfs_owner_info *oinfo,
enum xfs_ag_resv_type type)
{
struct xrep_extent *rex;
struct xrep_extent *n;
struct xfs_bitmap_range *bmr;
struct xfs_bitmap_range *n;
xfs_fsblock_t fsbno;
int error = 0;
ASSERT(xfs_sb_version_hasrmapbt(&sc->mp->m_sb));
/* Dispose of every block from the old btree. */
for_each_xrep_extent_safe(rex, n, exlist) {
for_each_xfs_bitmap_block(fsbno, bmr, n, bitmap) {
ASSERT(sc->ip != NULL ||
XFS_FSB_TO_AGNO(sc->mp, rex->fsbno) == sc->sa.agno);
XFS_FSB_TO_AGNO(sc->mp, fsbno) == sc->sa.agno);
trace_xrep_dispose_btree_extent(sc->mp,
XFS_FSB_TO_AGNO(sc->mp, rex->fsbno),
XFS_FSB_TO_AGBNO(sc->mp, rex->fsbno), rex->len);
XFS_FSB_TO_AGNO(sc->mp, fsbno),
XFS_FSB_TO_AGBNO(sc->mp, fsbno), 1);
for (; rex->len > 0; rex->len--, rex->fsbno++) {
error = xrep_dispose_btree_block(sc, rex->fsbno,
oinfo, type);
if (error)
goto out;
}
list_del(&rex->list);
kmem_free(rex);
error = xrep_reap_block(sc, fsbno, oinfo, type);
if (error)
goto out;
}
out:
xrep_cancel_btree_extents(sc, exlist);
xfs_bitmap_destroy(bitmap);
return error;
}

8
fs/xfs/scrub/repair.h
View File

@ -27,13 +27,11 @@ int xrep_init_btblock(struct xfs_scrub *sc, xfs_fsblock_t fsb,
struct xfs_buf **bpp, xfs_btnum_t btnum,
const struct xfs_buf_ops *ops);
struct xrep_extent_list;
struct xfs_bitmap;
int xrep_fix_freelist(struct xfs_scrub *sc, bool can_shrink);
int xrep_invalidate_blocks(struct xfs_scrub *sc,
struct xrep_extent_list *btlist);
int xrep_reap_btree_extents(struct xfs_scrub *sc,
struct xrep_extent_list *exlist,
int xrep_invalidate_blocks(struct xfs_scrub *sc, struct xfs_bitmap *btlist);
int xrep_reap_extents(struct xfs_scrub *sc, struct xfs_bitmap *exlist,
struct xfs_owner_info *oinfo, enum xfs_ag_resv_type type);
struct xrep_find_ag_btree {

1
fs/xfs/scrub/trace.h
View File

@ -511,7 +511,6 @@ DEFINE_EVENT(xrep_extent_class, name, \
xfs_agblock_t agbno, xfs_extlen_t len), \
TP_ARGS(mp, agno, agbno, len))
DEFINE_REPAIR_EXTENT_EVENT(xrep_dispose_btree_extent);
DEFINE_REPAIR_EXTENT_EVENT(xrep_collect_btree_extent);
DEFINE_REPAIR_EXTENT_EVENT(xrep_agfl_insert);
DECLARE_EVENT_CLASS(xrep_rmap_class,