Author: jeff
Date: Sat Apr 6 22:21:23 2013
New Revision: 249218
URL: http://svnweb.freebsd.org/changeset/base/249218
Log:
Prepare to replace the buf splay with a trie:
- Don't insert BKGRDMARKER bufs into the splay or dirty/clean buf lists.
No consumers need to find them there and it complicates the tree.
These flags are all FFS specific and could be moved out of the buf
cache.
- Use pbgetvp() and pbrelvp() to associate the background and journal
bufs with the vp. Not only is this much cheaper it makes more sense
for these transient bufs.
- Fix the assertions in pbget* and pbrel*. It's not safe to check list
pointers which were never initialized. Use the BX flags instead. We
also check B_PAGING in reassignbuf() so this should cover all cases.
Discussed with: kib, mckusick, attilio
Sponsored by: EMC / Isilon Storage Division
Modified:
head/sys/fs/ext2fs/ext2_alloc.c
head/sys/kern/vfs_subr.c
head/sys/ufs/ffs/ffs_softdep.c
head/sys/ufs/ffs/ffs_vfsops.c
head/sys/vm/vm_pager.c
Modified: head/sys/fs/ext2fs/ext2_alloc.c
==============================================================================
--- head/sys/fs/ext2fs/ext2_alloc.c Sat Apr 6 21:56:54 2013
(r249217)
+++ head/sys/fs/ext2fs/ext2_alloc.c Sat Apr 6 22:21:23 2013
(r249218)
@@ -794,8 +794,6 @@ ext2_clusteralloc(struct inode *ip, int
goto fail_lock;
bbp = (char *)bp->b_data;
- bp->b_xflags |= BX_BKGRDWRITE;
-
EXT2_LOCK(ump);
/*
* Check to see if a cluster of the needed size (or bigger) is
Modified: head/sys/kern/vfs_subr.c
==============================================================================
--- head/sys/kern/vfs_subr.c Sat Apr 6 21:56:54 2013 (r249217)
+++ head/sys/kern/vfs_subr.c Sat Apr 6 22:21:23 2013 (r249218)
@@ -1312,8 +1312,7 @@ flushbuflist(struct bufv *bufv, int flag
xflags = 0;
if (nbp != NULL) {
lblkno = nbp->b_lblkno;
- xflags = nbp->b_xflags &
- (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN);
+ xflags = nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN);
}
retval = EAGAIN;
error = BUF_TIMELOCK(bp,
@@ -1357,8 +1356,7 @@ flushbuflist(struct bufv *bufv, int flag
if (nbp != NULL &&
(nbp->b_bufobj != bo ||
nbp->b_lblkno != lblkno ||
- (nbp->b_xflags &
- (BX_BKGRDMARKER | BX_VNDIRTY | BX_VNCLEAN)) != xflags))
+ (nbp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) != xflags))
break; /* nbp invalid */
}
return (retval);
@@ -1501,9 +1499,7 @@ buf_splay(daddr_t lblkno, b_xflags_t xfl
return (NULL);
lefttreemax = righttreemin = &dummy;
for (;;) {
- if (lblkno < root->b_lblkno ||
- (lblkno == root->b_lblkno &&
- (xflags & BX_BKGRDMARKER) < (root->b_xflags &
BX_BKGRDMARKER))) {
+ if (lblkno < root->b_lblkno) {
if ((y = root->b_left) == NULL)
break;
if (lblkno < y->b_lblkno) {
@@ -1517,9 +1513,7 @@ buf_splay(daddr_t lblkno, b_xflags_t xfl
/* Link into the new root's right tree. */
righttreemin->b_left = root;
righttreemin = root;
- } else if (lblkno > root->b_lblkno ||
- (lblkno == root->b_lblkno &&
- (xflags & BX_BKGRDMARKER) > (root->b_xflags &
BX_BKGRDMARKER))) {
+ } else if (lblkno > root->b_lblkno) {
if ((y = root->b_right) == NULL)
break;
if (lblkno > y->b_lblkno) {
@@ -1603,9 +1597,7 @@ buf_vlist_add(struct buf *bp, struct buf
bp->b_left = NULL;
bp->b_right = NULL;
TAILQ_INSERT_TAIL(&bv->bv_hd, bp, b_bobufs);
- } else if (bp->b_lblkno < root->b_lblkno ||
- (bp->b_lblkno == root->b_lblkno &&
- (bp->b_xflags & BX_BKGRDMARKER) < (root->b_xflags &
BX_BKGRDMARKER))) {
+ } else if (bp->b_lblkno < root->b_lblkno) {
bp->b_left = root->b_left;
bp->b_right = root;
root->b_left = NULL;
@@ -1638,20 +1630,18 @@ gbincore(struct bufobj *bo, daddr_t lblk
struct buf *bp;
ASSERT_BO_LOCKED(bo);
- if ((bp = bo->bo_clean.bv_root) != NULL &&
- bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
+ if ((bp = bo->bo_clean.bv_root) != NULL && bp->b_lblkno == lblkno)
return (bp);
- if ((bp = bo->bo_dirty.bv_root) != NULL &&
- bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
+ if ((bp = bo->bo_dirty.bv_root) != NULL && bp->b_lblkno == lblkno)
return (bp);
if ((bp = bo->bo_clean.bv_root) != NULL) {
bo->bo_clean.bv_root = bp = buf_splay(lblkno, 0, bp);
- if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
+ if (bp->b_lblkno == lblkno)
return (bp);
}
if ((bp = bo->bo_dirty.bv_root) != NULL) {
bo->bo_dirty.bv_root = bp = buf_splay(lblkno, 0, bp);
- if (bp->b_lblkno == lblkno && !(bp->b_xflags & BX_BKGRDMARKER))
+ if (bp->b_lblkno == lblkno)
return (bp);
}
return (NULL);
Modified: head/sys/ufs/ffs/ffs_softdep.c
==============================================================================
--- head/sys/ufs/ffs/ffs_softdep.c Sat Apr 6 21:56:54 2013
(r249217)
+++ head/sys/ufs/ffs/ffs_softdep.c Sat Apr 6 22:21:23 2013
(r249218)
@@ -3285,7 +3285,6 @@ softdep_process_journal(mp, needwk, flag
bp->b_lblkno = bp->b_blkno;
bp->b_offset = bp->b_blkno * DEV_BSIZE;
bp->b_bcount = size;
- bp->b_bufobj = &ump->um_devvp->v_bufobj;
bp->b_flags &= ~B_INVAL;
bp->b_flags |= B_VALIDSUSPWRT | B_NOCOPY;
/*
@@ -3365,9 +3364,7 @@ softdep_process_journal(mp, needwk, flag
jblocks->jb_needseg = 0;
WORKLIST_INSERT(&bp->b_dep, &jseg->js_list);
FREE_LOCK(&lk);
- BO_LOCK(bp->b_bufobj);
- bgetvp(ump->um_devvp, bp);
- BO_UNLOCK(bp->b_bufobj);
+ pbgetvp(ump->um_devvp, bp);
/*
* We only do the blocking wait once we find the journal
* entry we're looking for.
@@ -3522,6 +3519,7 @@ handle_written_jseg(jseg, bp)
* discarded.
*/
bp->b_flags |= B_INVAL | B_NOCACHE;
+ pbrelvp(bp);
complete_jsegs(jseg);
}
@@ -11450,6 +11448,7 @@ handle_written_bmsafemap(bmsafemap, bp)
struct cg *cgp;
struct fs *fs;
ino_t ino;
+ int foreground;
int chgs;
if ((bmsafemap->sm_state & IOSTARTED) == 0)
@@ -11457,6 +11456,7 @@ handle_written_bmsafemap(bmsafemap, bp)
ump = VFSTOUFS(bmsafemap->sm_list.wk_mp);
chgs = 0;
bmsafemap->sm_state &= ~IOSTARTED;
+ foreground = (bp->b_xflags & BX_BKGRDMARKER) == 0;
/*
* Release journal work that was waiting on the write.
*/
@@ -11477,7 +11477,8 @@ handle_written_bmsafemap(bmsafemap, bp)
if (isset(inosused, ino))
panic("handle_written_bmsafemap: "
"re-allocated inode");
- if ((bp->b_xflags & BX_BKGRDMARKER) == 0) {
+ /* Do the roll-forward only if it's a real copy. */
+ if (foreground) {
if ((jaddref->ja_mode & IFMT) == IFDIR)
cgp->cg_cs.cs_ndir++;
cgp->cg_cs.cs_nifree--;
@@ -11500,7 +11501,8 @@ handle_written_bmsafemap(bmsafemap, bp)
jntmp) {
if ((jnewblk->jn_state & UNDONE) == 0)
continue;
- if ((bp->b_xflags & BX_BKGRDMARKER) == 0 &&
+ /* Do the roll-forward only if it's a real copy. */
+ if (foreground &&
jnewblk_rollforward(jnewblk, fs, cgp, blksfree))
chgs = 1;
jnewblk->jn_state &= ~(UNDONE | NEWBLOCK);
@@ -11540,7 +11542,8 @@ handle_written_bmsafemap(bmsafemap, bp)
return (0);
}
LIST_INSERT_HEAD(&ump->softdep_dirtycg, bmsafemap, sm_next);
- bdirty(bp);
+ if (foreground)
+ bdirty(bp);
return (1);
}
Modified: head/sys/ufs/ffs/ffs_vfsops.c
==============================================================================
--- head/sys/ufs/ffs/ffs_vfsops.c Sat Apr 6 21:56:54 2013
(r249217)
+++ head/sys/ufs/ffs/ffs_vfsops.c Sat Apr 6 22:21:23 2013
(r249218)
@@ -2000,12 +2000,11 @@ ffs_backgroundwritedone(struct buf *bp)
BO_LOCK(bufobj);
if ((origbp = gbincore(bp->b_bufobj, bp->b_lblkno)) == NULL)
panic("backgroundwritedone: lost buffer");
- /* Grab an extra reference to be dropped by the bufdone() below. */
- bufobj_wrefl(bufobj);
BO_UNLOCK(bufobj);
/*
* Process dependencies then return any unfinished ones.
*/
+ pbrelvp(bp);
if (!LIST_EMPTY(&bp->b_dep))
buf_complete(bp);
#ifdef SOFTUPDATES
@@ -2051,8 +2050,8 @@ ffs_backgroundwritedone(struct buf *bp)
static int
ffs_bufwrite(struct buf *bp)
{
- int oldflags, s;
struct buf *newbp;
+ int oldflags;
CTR3(KTR_BUF, "bufwrite(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
if (bp->b_flags & B_INVAL) {
@@ -2064,7 +2063,6 @@ ffs_bufwrite(struct buf *bp)
if (!BUF_ISLOCKED(bp))
panic("bufwrite: buffer is not busy???");
- s = splbio();
/*
* If a background write is already in progress, delay
* writing this block if it is asynchronous. Otherwise
@@ -2074,7 +2072,6 @@ ffs_bufwrite(struct buf *bp)
if (bp->b_vflags & BV_BKGRDINPROG) {
if (bp->b_flags & B_ASYNC) {
BO_UNLOCK(bp->b_bufobj);
- splx(s);
bdwrite(bp);
return (0);
}
@@ -2105,25 +2102,19 @@ ffs_bufwrite(struct buf *bp)
if (newbp == NULL)
goto normal_write;
- /*
- * set it to be identical to the old block. We have to
- * set b_lblkno and BKGRDMARKER before calling bgetvp()
- * to avoid confusing the splay tree and gbincore().
- */
KASSERT((bp->b_flags & B_UNMAPPED) == 0, ("Unmapped cg"));
memcpy(newbp->b_data, bp->b_data, bp->b_bufsize);
- newbp->b_lblkno = bp->b_lblkno;
- newbp->b_xflags |= BX_BKGRDMARKER;
BO_LOCK(bp->b_bufobj);
bp->b_vflags |= BV_BKGRDINPROG;
- bgetvp(bp->b_vp, newbp);
BO_UNLOCK(bp->b_bufobj);
- newbp->b_bufobj = &bp->b_vp->v_bufobj;
+ newbp->b_xflags |= BX_BKGRDMARKER;
+ newbp->b_lblkno = bp->b_lblkno;
newbp->b_blkno = bp->b_blkno;
newbp->b_offset = bp->b_offset;
newbp->b_iodone = ffs_backgroundwritedone;
newbp->b_flags |= B_ASYNC;
newbp->b_flags &= ~B_INVAL;
+ pbgetvp(bp->b_vp, newbp);
#ifdef SOFTUPDATES
/*
@@ -2139,12 +2130,9 @@ ffs_bufwrite(struct buf *bp)
#endif
/*
- * Initiate write on the copy, release the original to
- * the B_LOCKED queue so that it cannot go away until
- * the background write completes. If not locked it could go
- * away and then be reconstituted while it was being written.
- * If the reconstituted buffer were written, we could end up
- * with two background copies being written at the same time.
+ * Initiate write on the copy, release the original. The
+ * BKGRDINPROG flag prevents it from going away until
+ * the background write completes.
*/
bqrelse(bp);
bp = newbp;
Modified: head/sys/vm/vm_pager.c
==============================================================================
--- head/sys/vm/vm_pager.c Sat Apr 6 21:56:54 2013 (r249217)
+++ head/sys/vm/vm_pager.c Sat Apr 6 22:21:23 2013 (r249218)
@@ -469,17 +469,9 @@ pbrelvp(struct buf *bp)
KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL"));
KASSERT(bp->b_bufobj != NULL, ("pbrelvp: NULL bufobj"));
+ KASSERT((bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) == 0,
+ ("pbrelvp: pager buf on vnode list."));
- /* XXX REMOVE ME */
- BO_LOCK(bp->b_bufobj);
- if (TAILQ_NEXT(bp, b_bobufs) != NULL) {
- panic(
- "relpbuf(): b_vp was probably reassignbuf()d %p %x",
- bp,
- (int)bp->b_flags
- );
- }
- BO_UNLOCK(bp->b_bufobj);
bp->b_vp = NULL;
bp->b_bufobj = NULL;
bp->b_flags &= ~B_PAGING;
@@ -494,17 +486,9 @@ pbrelbo(struct buf *bp)
KASSERT(bp->b_vp == NULL, ("pbrelbo: vnode"));
KASSERT(bp->b_bufobj != NULL, ("pbrelbo: NULL bufobj"));
+ KASSERT((bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) == 0,
+ ("pbrelbo: pager buf on vnode list."));
- /* XXX REMOVE ME */
- BO_LOCK(bp->b_bufobj);
- if (TAILQ_NEXT(bp, b_bobufs) != NULL) {
- panic(
- "relpbuf(): b_vp was probably reassignbuf()d %p %x",
- bp,
- (int)bp->b_flags
- );
- }
- BO_UNLOCK(bp->b_bufobj);
bp->b_bufobj = NULL;
bp->b_flags &= ~B_PAGING;
}
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