| Message ID | 20201022051537.2286402-6-david@fromorbit.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | repair: Phase 6 performance improvements | expand |
On Thu, Oct 22, 2020 at 04:15:35PM +1100, Dave Chinner wrote: > From: Dave Chinner <dchinner@redhat.com> > > The name hash in phase 6 is constructed by using names that point > directly into the directory buffers. Hence before the buffers can be > released, the constructed name hash has to duplicate all those names > into meory it owns via dir_hash_dup_names(). > > Given that the structure that holds the name is dynamically > allocated, it makes no sense to store a pointer to the name > dir_hash_add() and then later have dynamically allocate the name. > > Extend the name hash allocation to contain space for the name > itself, and copy the name into the name hash structure in > dir_hash_add(). This allows us to get rid of dir_hash_dup_names(), > and the directory checking code no longer needs to hold all the > directory buffers in memory until the entire directory walk is > complete and the names duplicated. > > Signed-off-by: Dave Chinner <dchinner@redhat.com> > --- > repair/phase6.c | 101 ++++++++++++++---------------------------------- > 1 file changed, 29 insertions(+), 72 deletions(-) > > diff --git a/repair/phase6.c b/repair/phase6.c > index bf0719c186fb..79c87495656f 100644 > --- a/repair/phase6.c > +++ b/repair/phase6.c > @@ -72,7 +72,7 @@ typedef struct dir_hash_ent { > struct dir_hash_ent *nextbyorder; /* next in order added */ > xfs_dahash_t hashval; /* hash value of name */ > uint32_t address; /* offset of data entry */ > - xfs_ino_t inum; /* inode num of entry */ > + xfs_ino_t inum; /* inode num of entry */ > short junkit; /* name starts with / */ > short seen; /* have seen leaf entry */ > struct xfs_name name; > @@ -80,7 +80,6 @@ typedef struct dir_hash_ent { > > typedef struct dir_hash_tab { > int size; /* size of hash tables */ > - int names_duped; /* 1 = ent names malloced */ > dir_hash_ent_t *first; /* ptr to first added entry */ > dir_hash_ent_t *last; /* ptr to last added entry */ > dir_hash_ent_t **byhash; /* ptr to name hash buckets */ > @@ -171,8 +170,6 @@ dir_hash_add( > short junk; > struct xfs_name xname; > > - ASSERT(!hashtab->names_duped); > - > xname.name = name; > xname.len = namelen; > xname.type = ftype; > @@ -199,7 +196,12 @@ dir_hash_add( > } > } > > - if ((p = malloc(sizeof(*p))) == NULL) > + /* > + * Allocate enough space for the hash entry and the name in a single > + * allocation so we can store our own copy of the name for later use. > + */ > + p = calloc(1, sizeof(*p) + namelen + 1); > + if (!p) > do_error(_("malloc failed in dir_hash_add (%zu bytes)\n"), > sizeof(*p)); > > @@ -220,7 +222,12 @@ dir_hash_add( > p->address = addr; > p->inum = inum; > p->seen = 0; > - p->name = xname; > + > + /* Set up the name in the region trailing the hash entry. */ > + memcpy(p + 1, name, namelen); > + p->name.name = (const unsigned char *)(p + 1); > + p->name.len = namelen; > + p->name.type = ftype; > > return !dup; > } > @@ -287,8 +294,6 @@ dir_hash_done( > for (i = 0; i < hashtab->size; i++) { > for (p = hashtab->byaddr[i]; p; p = n) { > n = p->nextbyaddr; > - if (hashtab->names_duped) > - free((void *)p->name.name); > free(p); > } > } > @@ -385,27 +390,6 @@ dir_hash_see_all( > return j == stale ? DIR_HASH_CK_OK : DIR_HASH_CK_BADSTALE; > } > > -/* > - * Convert name pointers into locally allocated memory. > - * This must only be done after all the entries have been added. > - */ > -static void > -dir_hash_dup_names(dir_hash_tab_t *hashtab) > -{ > - unsigned char *name; > - dir_hash_ent_t *p; > - > - if (hashtab->names_duped) > - return; > - > - for (p = hashtab->first; p; p = p->nextbyorder) { > - name = malloc(p->name.len); > - memcpy(name, p->name.name, p->name.len); > - p->name.name = name; > - } > - hashtab->names_duped = 1; > -} > - > /* > * Given a block number in a fork, return the next valid block number > * (not a hole). > @@ -1387,6 +1371,7 @@ dir2_kill_block( > res_failed(error); > libxfs_trans_ijoin(tp, ip, 0); > libxfs_trans_bjoin(tp, bp); > + libxfs_trans_bhold(tp, bp); Why hold on to the buffer? We killed the block, why keep the reference around so that someone else has to remember to drop it later? Hooray for killing that bplist thing later though. :) --D > memset(&args, 0, sizeof(args)); > args.dp = ip; > args.trans = tp; > @@ -1418,7 +1403,7 @@ longform_dir2_entry_check_data( > int *need_dot, > ino_tree_node_t *current_irec, > int current_ino_offset, > - struct xfs_buf **bpp, > + struct xfs_buf *bp, > dir_hash_tab_t *hashtab, > freetab_t **freetabp, > xfs_dablk_t da_bno, > @@ -1426,7 +1411,6 @@ longform_dir2_entry_check_data( > { > xfs_dir2_dataptr_t addr; > xfs_dir2_leaf_entry_t *blp; > - struct xfs_buf *bp; > xfs_dir2_block_tail_t *btp; > struct xfs_dir2_data_hdr *d; > xfs_dir2_db_t db; > @@ -1457,7 +1441,6 @@ longform_dir2_entry_check_data( > }; > > > - bp = *bpp; > d = bp->b_addr; > ptr = (char *)d + mp->m_dir_geo->data_entry_offset; > nbad = 0; > @@ -1558,10 +1541,8 @@ longform_dir2_entry_check_data( > dir2_kill_block(mp, ip, da_bno, bp); > } else { > do_warn(_("would junk block\n")); > - libxfs_buf_relse(bp); > } > freetab->ents[db].v = NULLDATAOFF; > - *bpp = NULL; > return; > } > > @@ -2219,17 +2200,15 @@ longform_dir2_entry_check(xfs_mount_t *mp, > int ino_offset, > dir_hash_tab_t *hashtab) > { > - struct xfs_buf **bplist; > + struct xfs_buf *bp; > xfs_dablk_t da_bno; > freetab_t *freetab; > - int num_bps; > int i; > int isblock; > int isleaf; > xfs_fileoff_t next_da_bno; > int seeval; > int fixit = 0; > - xfs_dir2_db_t db; > struct xfs_da_args args; > > *need_dot = 1; > @@ -2246,11 +2225,6 @@ longform_dir2_entry_check(xfs_mount_t *mp, > freetab->ents[i].v = NULLDATAOFF; > freetab->ents[i].s = 0; > } > - num_bps = freetab->naents; > - bplist = calloc(num_bps, sizeof(struct xfs_buf*)); > - if (!bplist) > - do_error(_("calloc failed in %s (%zu bytes)\n"), > - __func__, num_bps * sizeof(struct xfs_buf*)); > > /* is this a block, leaf, or node directory? */ > args.dp = ip; > @@ -2279,28 +2253,12 @@ longform_dir2_entry_check(xfs_mount_t *mp, > break; > } > > - db = xfs_dir2_da_to_db(mp->m_dir_geo, da_bno); > - if (db >= num_bps) { > - int last_size = num_bps; > - > - /* more data blocks than expected */ > - num_bps = db + 1; > - bplist = realloc(bplist, num_bps * sizeof(struct xfs_buf*)); > - if (!bplist) > - do_error(_("realloc failed in %s (%zu bytes)\n"), > - __func__, > - num_bps * sizeof(struct xfs_buf*)); > - /* Initialize the new elements */ > - for (i = last_size; i < num_bps; i++) > - bplist[i] = NULL; > - } > - > if (isblock) > ops = &xfs_dir3_block_buf_ops; > else > ops = &xfs_dir3_data_buf_ops; > > - error = dir_read_buf(ip, da_bno, &bplist[db], ops, &fixit); > + error = dir_read_buf(ip, da_bno, &bp, ops, &fixit); > if (error) { > do_warn( > _("can't read data block %u for directory inode %" PRIu64 " error %d\n"), > @@ -2320,21 +2278,25 @@ longform_dir2_entry_check(xfs_mount_t *mp, > } > > /* check v5 metadata */ > - d = bplist[db]->b_addr; > + d = bp->b_addr; > if (be32_to_cpu(d->magic) == XFS_DIR3_BLOCK_MAGIC || > be32_to_cpu(d->magic) == XFS_DIR3_DATA_MAGIC) { > - struct xfs_buf *bp = bplist[db]; > - > error = check_dir3_header(mp, bp, ino); > if (error) { > fixit++; > + if (isblock) > + goto out_fix; > continue; > } > } > > longform_dir2_entry_check_data(mp, ip, num_illegal, need_dot, > - irec, ino_offset, &bplist[db], hashtab, > + irec, ino_offset, bp, hashtab, > &freetab, da_bno, isblock); > + if (isblock) > + break; > + > + libxfs_buf_relse(bp); > } > fixit |= (*num_illegal != 0) || dir2_is_badino(ino) || *need_dot; > > @@ -2345,7 +2307,7 @@ longform_dir2_entry_check(xfs_mount_t *mp, > xfs_dir2_block_tail_t *btp; > xfs_dir2_leaf_entry_t *blp; > > - block = bplist[0]->b_addr; > + block = bp->b_addr; > btp = xfs_dir2_block_tail_p(mp->m_dir_geo, block); > blp = xfs_dir2_block_leaf_p(btp); > seeval = dir_hash_see_all(hashtab, blp, > @@ -2362,11 +2324,10 @@ longform_dir2_entry_check(xfs_mount_t *mp, > } > } > out_fix: > + if (isblock && bp) > + libxfs_buf_relse(bp); > + > if (!no_modify && (fixit || dotdot_update)) { > - dir_hash_dup_names(hashtab); > - for (i = 0; i < num_bps; i++) > - if (bplist[i]) > - libxfs_buf_relse(bplist[i]); > longform_dir2_rebuild(mp, ino, ip, irec, ino_offset, hashtab); > *num_illegal = 0; > *need_dot = 0; > @@ -2374,12 +2335,8 @@ out_fix: > if (fixit || dotdot_update) > do_warn( > _("would rebuild directory inode %" PRIu64 "\n"), ino); > - for (i = 0; i < num_bps; i++) > - if (bplist[i]) > - libxfs_buf_relse(bplist[i]); > } > > - free(bplist); > free(freetab); > } > > -- > 2.28.0 >
On Wed, Oct 21, 2020 at 11:21:52PM -0700, Darrick J. Wong wrote: > On Thu, Oct 22, 2020 at 04:15:35PM +1100, Dave Chinner wrote: .... > > @@ -1387,6 +1371,7 @@ dir2_kill_block( > > res_failed(error); > > libxfs_trans_ijoin(tp, ip, 0); > > libxfs_trans_bjoin(tp, bp); > > + libxfs_trans_bhold(tp, bp); > > Why hold on to the buffer? We killed the block, why keep the reference > around so that someone else has to remember to drop it later? Consistency in buffer handling. This "kill block" path nulled out the buffer in the bplist array (the reason it's passed as a **bpp to longform_dir2_entry_check_data(). This path releases the buffer through the trans_commit(), the alternate path here: > > @@ -1558,10 +1541,8 @@ longform_dir2_entry_check_data( > > dir2_kill_block(mp, ip, da_bno, bp); > > } else { > > do_warn(_("would junk block\n")); > > - libxfs_buf_relse(bp); > > } > > freetab->ents[db].v = NULLDATAOFF; > > - *bpp = NULL; > > return; > > } does an explicit release, and all other paths end up with the buffers being released way back where the bplist is defined. If the directory is in block form, nulling out the buffer in the bplist here will result in dereferencing a null pointer later when the buffer is pulled from bplist[0] without checking. So I changed longform_dir2_entry_check_data() to never release the buffer so that the caller knows that it has always got a valid buffer reference and the isblock path will always work correctly.... Cheers, Dave.
On Thu, Oct 22, 2020 at 07:23:54PM +1100, Dave Chinner wrote: > On Wed, Oct 21, 2020 at 11:21:52PM -0700, Darrick J. Wong wrote: > > On Thu, Oct 22, 2020 at 04:15:35PM +1100, Dave Chinner wrote: > .... > > > @@ -1387,6 +1371,7 @@ dir2_kill_block( > > > res_failed(error); > > > libxfs_trans_ijoin(tp, ip, 0); > > > libxfs_trans_bjoin(tp, bp); > > > + libxfs_trans_bhold(tp, bp); > > > > Why hold on to the buffer? We killed the block, why keep the reference > > around so that someone else has to remember to drop it later? > > Consistency in buffer handling. This "kill block" path nulled out > the buffer in the bplist array (the reason it's passed as a **bpp > to longform_dir2_entry_check_data(). This path releases the buffer > through the trans_commit(), the alternate path here: > > > > @@ -1558,10 +1541,8 @@ longform_dir2_entry_check_data( > > > dir2_kill_block(mp, ip, da_bno, bp); > > > } else { > > > do_warn(_("would junk block\n")); > > > - libxfs_buf_relse(bp); > > > } > > > freetab->ents[db].v = NULLDATAOFF; > > > - *bpp = NULL; > > > return; > > > } > > does an explicit release, and all other paths end up with the > buffers being released way back where the bplist is defined. > > If the directory is in block form, nulling out the buffer in the > bplist here will result in dereferencing a null pointer later when > the buffer is pulled from bplist[0] without checking. > > So I changed longform_dir2_entry_check_data() to never release the > buffer so that the caller knows that it has always got a valid > buffer reference and the isblock path will always work correctly.... Hmmm, looking through the directory code, I see that it calls binval to stale the buffer, so the kill_block caller won't be able to do much with its incore reference. Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> --D > > Cheers, > > Dave. > > > -- > Dave Chinner > david@fromorbit.com
> - xfs_ino_t inum; /* inode num of entry */ > + xfs_ino_t inum; /* inode num of entry */ spurious unrelated whitespace change? > + /* Set up the name in the region trailing the hash entry. */ > + memcpy(p + 1, name, namelen); > + p->name.name = (const unsigned char *)(p + 1); > + p->name.len = namelen; > + p->name.type = ftype; just add a char namebuf[]; to the end of struct dir_hash_ent and use that. This has the same memory usage, but avoids the cast and pointer arithmetics magic.
diff --git a/repair/phase6.c b/repair/phase6.c index bf0719c186fb..79c87495656f 100644 --- a/repair/phase6.c +++ b/repair/phase6.c @@ -72,7 +72,7 @@ typedef struct dir_hash_ent { struct dir_hash_ent *nextbyorder; /* next in order added */ xfs_dahash_t hashval; /* hash value of name */ uint32_t address; /* offset of data entry */ - xfs_ino_t inum; /* inode num of entry */ + xfs_ino_t inum; /* inode num of entry */ short junkit; /* name starts with / */ short seen; /* have seen leaf entry */ struct xfs_name name; @@ -80,7 +80,6 @@ typedef struct dir_hash_ent { typedef struct dir_hash_tab { int size; /* size of hash tables */ - int names_duped; /* 1 = ent names malloced */ dir_hash_ent_t *first; /* ptr to first added entry */ dir_hash_ent_t *last; /* ptr to last added entry */ dir_hash_ent_t **byhash; /* ptr to name hash buckets */ @@ -171,8 +170,6 @@ dir_hash_add( short junk; struct xfs_name xname; - ASSERT(!hashtab->names_duped); - xname.name = name; xname.len = namelen; xname.type = ftype; @@ -199,7 +196,12 @@ dir_hash_add( } } - if ((p = malloc(sizeof(*p))) == NULL) + /* + * Allocate enough space for the hash entry and the name in a single + * allocation so we can store our own copy of the name for later use. + */ + p = calloc(1, sizeof(*p) + namelen + 1); + if (!p) do_error(_("malloc failed in dir_hash_add (%zu bytes)\n"), sizeof(*p)); @@ -220,7 +222,12 @@ dir_hash_add( p->address = addr; p->inum = inum; p->seen = 0; - p->name = xname; + + /* Set up the name in the region trailing the hash entry. */ + memcpy(p + 1, name, namelen); + p->name.name = (const unsigned char *)(p + 1); + p->name.len = namelen; + p->name.type = ftype; return !dup; } @@ -287,8 +294,6 @@ dir_hash_done( for (i = 0; i < hashtab->size; i++) { for (p = hashtab->byaddr[i]; p; p = n) { n = p->nextbyaddr; - if (hashtab->names_duped) - free((void *)p->name.name); free(p); } } @@ -385,27 +390,6 @@ dir_hash_see_all( return j == stale ? DIR_HASH_CK_OK : DIR_HASH_CK_BADSTALE; } -/* - * Convert name pointers into locally allocated memory. - * This must only be done after all the entries have been added. - */ -static void -dir_hash_dup_names(dir_hash_tab_t *hashtab) -{ - unsigned char *name; - dir_hash_ent_t *p; - - if (hashtab->names_duped) - return; - - for (p = hashtab->first; p; p = p->nextbyorder) { - name = malloc(p->name.len); - memcpy(name, p->name.name, p->name.len); - p->name.name = name; - } - hashtab->names_duped = 1; -} - /* * Given a block number in a fork, return the next valid block number * (not a hole). @@ -1387,6 +1371,7 @@ dir2_kill_block( res_failed(error); libxfs_trans_ijoin(tp, ip, 0); libxfs_trans_bjoin(tp, bp); + libxfs_trans_bhold(tp, bp); memset(&args, 0, sizeof(args)); args.dp = ip; args.trans = tp; @@ -1418,7 +1403,7 @@ longform_dir2_entry_check_data( int *need_dot, ino_tree_node_t *current_irec, int current_ino_offset, - struct xfs_buf **bpp, + struct xfs_buf *bp, dir_hash_tab_t *hashtab, freetab_t **freetabp, xfs_dablk_t da_bno, @@ -1426,7 +1411,6 @@ longform_dir2_entry_check_data( { xfs_dir2_dataptr_t addr; xfs_dir2_leaf_entry_t *blp; - struct xfs_buf *bp; xfs_dir2_block_tail_t *btp; struct xfs_dir2_data_hdr *d; xfs_dir2_db_t db; @@ -1457,7 +1441,6 @@ longform_dir2_entry_check_data( }; - bp = *bpp; d = bp->b_addr; ptr = (char *)d + mp->m_dir_geo->data_entry_offset; nbad = 0; @@ -1558,10 +1541,8 @@ longform_dir2_entry_check_data( dir2_kill_block(mp, ip, da_bno, bp); } else { do_warn(_("would junk block\n")); - libxfs_buf_relse(bp); } freetab->ents[db].v = NULLDATAOFF; - *bpp = NULL; return; } @@ -2219,17 +2200,15 @@ longform_dir2_entry_check(xfs_mount_t *mp, int ino_offset, dir_hash_tab_t *hashtab) { - struct xfs_buf **bplist; + struct xfs_buf *bp; xfs_dablk_t da_bno; freetab_t *freetab; - int num_bps; int i; int isblock; int isleaf; xfs_fileoff_t next_da_bno; int seeval; int fixit = 0; - xfs_dir2_db_t db; struct xfs_da_args args; *need_dot = 1; @@ -2246,11 +2225,6 @@ longform_dir2_entry_check(xfs_mount_t *mp, freetab->ents[i].v = NULLDATAOFF; freetab->ents[i].s = 0; } - num_bps = freetab->naents; - bplist = calloc(num_bps, sizeof(struct xfs_buf*)); - if (!bplist) - do_error(_("calloc failed in %s (%zu bytes)\n"), - __func__, num_bps * sizeof(struct xfs_buf*)); /* is this a block, leaf, or node directory? */ args.dp = ip; @@ -2279,28 +2253,12 @@ longform_dir2_entry_check(xfs_mount_t *mp, break; } - db = xfs_dir2_da_to_db(mp->m_dir_geo, da_bno); - if (db >= num_bps) { - int last_size = num_bps; - - /* more data blocks than expected */ - num_bps = db + 1; - bplist = realloc(bplist, num_bps * sizeof(struct xfs_buf*)); - if (!bplist) - do_error(_("realloc failed in %s (%zu bytes)\n"), - __func__, - num_bps * sizeof(struct xfs_buf*)); - /* Initialize the new elements */ - for (i = last_size; i < num_bps; i++) - bplist[i] = NULL; - } - if (isblock) ops = &xfs_dir3_block_buf_ops; else ops = &xfs_dir3_data_buf_ops; - error = dir_read_buf(ip, da_bno, &bplist[db], ops, &fixit); + error = dir_read_buf(ip, da_bno, &bp, ops, &fixit); if (error) { do_warn( _("can't read data block %u for directory inode %" PRIu64 " error %d\n"), @@ -2320,21 +2278,25 @@ longform_dir2_entry_check(xfs_mount_t *mp, } /* check v5 metadata */ - d = bplist[db]->b_addr; + d = bp->b_addr; if (be32_to_cpu(d->magic) == XFS_DIR3_BLOCK_MAGIC || be32_to_cpu(d->magic) == XFS_DIR3_DATA_MAGIC) { - struct xfs_buf *bp = bplist[db]; - error = check_dir3_header(mp, bp, ino); if (error) { fixit++; + if (isblock) + goto out_fix; continue; } } longform_dir2_entry_check_data(mp, ip, num_illegal, need_dot, - irec, ino_offset, &bplist[db], hashtab, + irec, ino_offset, bp, hashtab, &freetab, da_bno, isblock); + if (isblock) + break; + + libxfs_buf_relse(bp); } fixit |= (*num_illegal != 0) || dir2_is_badino(ino) || *need_dot; @@ -2345,7 +2307,7 @@ longform_dir2_entry_check(xfs_mount_t *mp, xfs_dir2_block_tail_t *btp; xfs_dir2_leaf_entry_t *blp; - block = bplist[0]->b_addr; + block = bp->b_addr; btp = xfs_dir2_block_tail_p(mp->m_dir_geo, block); blp = xfs_dir2_block_leaf_p(btp); seeval = dir_hash_see_all(hashtab, blp, @@ -2362,11 +2324,10 @@ longform_dir2_entry_check(xfs_mount_t *mp, } } out_fix: + if (isblock && bp) + libxfs_buf_relse(bp); + if (!no_modify && (fixit || dotdot_update)) { - dir_hash_dup_names(hashtab); - for (i = 0; i < num_bps; i++) - if (bplist[i]) - libxfs_buf_relse(bplist[i]); longform_dir2_rebuild(mp, ino, ip, irec, ino_offset, hashtab); *num_illegal = 0; *need_dot = 0; @@ -2374,12 +2335,8 @@ out_fix: if (fixit || dotdot_update) do_warn( _("would rebuild directory inode %" PRIu64 "\n"), ino); - for (i = 0; i < num_bps; i++) - if (bplist[i]) - libxfs_buf_relse(bplist[i]); } - free(bplist); free(freetab); }