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authorsanjeevbagewadi <[email protected]>2018-02-09 23:45:53 +0530
committerBrian Behlendorf <[email protected]>2018-02-09 10:15:53 -0800
commitcc63068e95ee725cce03b1b7ce50179825a6cda5 (patch)
treea9f4def7be1a9f9f49f299c858113fef982b0145 /module
parenteb9c4532dda34bcf0612c2c797cb3fcab9a21b4f (diff)
Handle zap_add() failures in mixed case mode
With "casesensitivity=mixed", zap_add() could fail when the number of files/directories with the same name (varying in case) exceed the capacity of the leaf node of a Fatzap. This results in a ASSERT() failure as zfs_link_create() does not expect zap_add() to fail. The fix is to handle these failures and rollback the transactions. Reviewed by: Matt Ahrens <[email protected]> Reviewed-by: Chunwei Chen <[email protected]> Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Sanjeev Bagewadi <[email protected]> Closes #7011 Closes #7054
Diffstat (limited to 'module')
-rw-r--r--module/zfs/zap.c25
-rw-r--r--module/zfs/zap_leaf.c2
-rw-r--r--module/zfs/zap_micro.c38
-rw-r--r--module/zfs/zfs_dir.c29
-rw-r--r--module/zfs/zfs_vnops.c74
5 files changed, 141 insertions, 27 deletions
diff --git a/module/zfs/zap.c b/module/zfs/zap.c
index 2f6aed667..1c2030bda 100644
--- a/module/zfs/zap.c
+++ b/module/zfs/zap.c
@@ -818,15 +818,19 @@ fzap_lookup(zap_name_t *zn,
return (err);
}
+#define MAX_EXPAND_RETRIES 2
+
int
fzap_add_cd(zap_name_t *zn,
uint64_t integer_size, uint64_t num_integers,
const void *val, uint32_t cd, void *tag, dmu_tx_t *tx)
{
zap_leaf_t *l;
+ zap_leaf_t *prev_l = NULL;
int err;
zap_entry_handle_t zeh;
zap_t *zap = zn->zn_zap;
+ int expand_retries = 0;
ASSERT(RW_LOCK_HELD(&zap->zap_rwlock));
ASSERT(!zap->zap_ismicro);
@@ -850,10 +854,29 @@ retry:
if (err == 0) {
zap_increment_num_entries(zap, 1, tx);
} else if (err == EAGAIN) {
+ /*
+ * If the last two expansions did not help, there is no point
+ * trying to expand again
+ */
+ if (expand_retries > MAX_EXPAND_RETRIES && prev_l == l) {
+ err = SET_ERROR(ENOSPC);
+ goto out;
+ }
+
err = zap_expand_leaf(zn, l, tag, tx, &l);
zap = zn->zn_zap; /* zap_expand_leaf() may change zap */
- if (err == 0)
+ if (err == 0) {
+ prev_l = l;
+ expand_retries++;
goto retry;
+ } else if (err == ENOSPC) {
+ /*
+ * If we failed to expand the leaf, then bailout
+ * as there is no point trying
+ * zap_put_leaf_maybe_grow_ptrtbl().
+ */
+ return (err);
+ }
}
out:
diff --git a/module/zfs/zap_leaf.c b/module/zfs/zap_leaf.c
index 5341fc098..661fd747b 100644
--- a/module/zfs/zap_leaf.c
+++ b/module/zfs/zap_leaf.c
@@ -53,7 +53,7 @@ static uint16_t *zap_leaf_rehash_entry(zap_leaf_t *l, uint16_t entry);
((h) >> \
(64 - ZAP_LEAF_HASH_SHIFT(l) - zap_leaf_phys(l)->l_hdr.lh_prefix_len)))
-#define LEAF_HASH_ENTPTR(l, h) (&zap_leaf_phys(l)->l_hash[LEAF_HASH(l, h)])
+#define LEAF_HASH_ENTPTR(l, h) (&zap_leaf_phys(l)->l_hash[LEAF_HASH(l, h)])
extern inline zap_leaf_phys_t *zap_leaf_phys(zap_leaf_t *l);
diff --git a/module/zfs/zap_micro.c b/module/zfs/zap_micro.c
index b81a48a0f..ad9a62161 100644
--- a/module/zfs/zap_micro.c
+++ b/module/zfs/zap_micro.c
@@ -363,6 +363,41 @@ mze_find_unused_cd(zap_t *zap, uint64_t hash)
return (cd);
}
+/*
+ * Each mzap entry requires at max : 4 chunks
+ * 3 chunks for names + 1 chunk for value.
+ */
+#define MZAP_ENT_CHUNKS (1 + ZAP_LEAF_ARRAY_NCHUNKS(MZAP_NAME_LEN) + \
+ ZAP_LEAF_ARRAY_NCHUNKS(sizeof (uint64_t)))
+
+/*
+ * Check if the current entry keeps the colliding entries under the fatzap leaf
+ * size.
+ */
+static boolean_t
+mze_canfit_fzap_leaf(zap_name_t *zn, uint64_t hash)
+{
+ zap_t *zap = zn->zn_zap;
+ mzap_ent_t mze_tofind;
+ mzap_ent_t *mze;
+ avl_index_t idx;
+ avl_tree_t *avl = &zap->zap_m.zap_avl;
+ uint32_t mzap_ents = 0;
+
+ mze_tofind.mze_hash = hash;
+ mze_tofind.mze_cd = 0;
+
+ for (mze = avl_find(avl, &mze_tofind, &idx);
+ mze && mze->mze_hash == hash; mze = AVL_NEXT(avl, mze)) {
+ mzap_ents++;
+ }
+
+ /* Include the new entry being added */
+ mzap_ents++;
+
+ return (ZAP_LEAF_NUMCHUNKS_DEF > (mzap_ents * MZAP_ENT_CHUNKS));
+}
+
static void
mze_remove(zap_t *zap, mzap_ent_t *mze)
{
@@ -1190,7 +1225,8 @@ zap_add_impl(zap_t *zap, const char *key,
err = fzap_add(zn, integer_size, num_integers, val, tag, tx);
zap = zn->zn_zap; /* fzap_add() may change zap */
} else if (integer_size != 8 || num_integers != 1 ||
- strlen(key) >= MZAP_NAME_LEN) {
+ strlen(key) >= MZAP_NAME_LEN ||
+ !mze_canfit_fzap_leaf(zn, zn->zn_hash)) {
err = mzap_upgrade(&zn->zn_zap, tag, tx, 0);
if (err == 0) {
err = fzap_add(zn, integer_size, num_integers, val,
diff --git a/module/zfs/zfs_dir.c b/module/zfs/zfs_dir.c
index 9a8bbccd9..6398a1d15 100644
--- a/module/zfs/zfs_dir.c
+++ b/module/zfs/zfs_dir.c
@@ -742,7 +742,11 @@ zfs_dirent(znode_t *zp, uint64_t mode)
}
/*
- * Link zp into dl. Can only fail if zp has been unlinked.
+ * Link zp into dl. Can fail in the following cases :
+ * - if zp has been unlinked.
+ * - if the number of entries with the same hash (aka. colliding entries)
+ * exceed the capacity of a leaf-block of fatzap and splitting of the
+ * leaf-block does not help.
*/
int
zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag)
@@ -776,6 +780,24 @@ zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag)
NULL, &links, sizeof (links));
}
}
+
+ value = zfs_dirent(zp, zp->z_mode);
+ error = zap_add(ZTOZSB(zp)->z_os, dzp->z_id, dl->dl_name, 8, 1,
+ &value, tx);
+
+ /*
+ * zap_add could fail to add the entry if it exceeds the capacity of the
+ * leaf-block and zap_leaf_split() failed to help.
+ * The caller of this routine is responsible for failing the transaction
+ * which will rollback the SA updates done above.
+ */
+ if (error != 0) {
+ if (!(flag & ZRENAMING) && !(flag & ZNEW))
+ drop_nlink(ZTOI(zp));
+ mutex_exit(&zp->z_lock);
+ return (error);
+ }
+
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_PARENT(zfsvfs), NULL,
&dzp->z_id, sizeof (dzp->z_id));
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
@@ -813,11 +835,6 @@ zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag)
ASSERT(error == 0);
mutex_exit(&dzp->z_lock);
- value = zfs_dirent(zp, zp->z_mode);
- error = zap_add(ZTOZSB(zp)->z_os, dzp->z_id, dl->dl_name,
- 8, 1, &value, tx);
- ASSERT(error == 0);
-
return (0);
}
diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c
index 5e34cb2ff..e21fe1aca 100644
--- a/module/zfs/zfs_vnops.c
+++ b/module/zfs/zfs_vnops.c
@@ -1429,6 +1429,7 @@ top:
dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
0, acl_ids.z_aclp->z_acl_bytes);
}
+
error = dmu_tx_assign(tx,
(waited ? TXG_NOTHROTTLE : 0) | TXG_NOWAIT);
if (error) {
@@ -1446,10 +1447,22 @@ top:
}
zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
+ error = zfs_link_create(dl, zp, tx, ZNEW);
+ if (error != 0) {
+ /*
+ * Since, we failed to add the directory entry for it,
+ * delete the newly created dnode.
+ */
+ zfs_znode_delete(zp, tx);
+ remove_inode_hash(ZTOI(zp));
+ zfs_acl_ids_free(&acl_ids);
+ dmu_tx_commit(tx);
+ goto out;
+ }
+
if (fuid_dirtied)
zfs_fuid_sync(zfsvfs, tx);
- (void) zfs_link_create(dl, zp, tx, ZNEW);
txtype = zfs_log_create_txtype(Z_FILE, vsecp, vap);
if (flag & FIGNORECASE)
txtype |= TX_CI;
@@ -2040,13 +2053,18 @@ top:
*/
zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
- if (fuid_dirtied)
- zfs_fuid_sync(zfsvfs, tx);
-
/*
* Now put new name in parent dir.
*/
- (void) zfs_link_create(dl, zp, tx, ZNEW);
+ error = zfs_link_create(dl, zp, tx, ZNEW);
+ if (error != 0) {
+ zfs_znode_delete(zp, tx);
+ remove_inode_hash(ZTOI(zp));
+ goto out;
+ }
+
+ if (fuid_dirtied)
+ zfs_fuid_sync(zfsvfs, tx);
*ipp = ZTOI(zp);
@@ -2056,6 +2074,7 @@ top:
zfs_log_create(zilog, tx, txtype, dzp, zp, dirname, vsecp,
acl_ids.z_fuidp, vap);
+out:
zfs_acl_ids_free(&acl_ids);
dmu_tx_commit(tx);
@@ -2065,10 +2084,14 @@ top:
if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
zil_commit(zilog, 0);
- zfs_inode_update(dzp);
- zfs_inode_update(zp);
+ if (error != 0) {
+ iput(ZTOI(zp));
+ } else {
+ zfs_inode_update(dzp);
+ zfs_inode_update(zp);
+ }
ZFS_EXIT(zfsvfs);
- return (0);
+ return (error);
}
/*
@@ -3686,6 +3709,13 @@ top:
VERIFY3U(zfs_link_destroy(tdl, szp, tx,
ZRENAMING, NULL), ==, 0);
}
+ } else {
+ /*
+ * If we had removed the existing target, subsequent
+ * call to zfs_link_create() to add back the same entry
+ * but, the new dnode (szp) should not fail.
+ */
+ ASSERT(tzp == NULL);
}
}
@@ -3856,14 +3886,18 @@ top:
/*
* Insert the new object into the directory.
*/
- (void) zfs_link_create(dl, zp, tx, ZNEW);
-
- if (flags & FIGNORECASE)
- txtype |= TX_CI;
- zfs_log_symlink(zilog, tx, txtype, dzp, zp, name, link);
+ error = zfs_link_create(dl, zp, tx, ZNEW);
+ if (error != 0) {
+ zfs_znode_delete(zp, tx);
+ remove_inode_hash(ZTOI(zp));
+ } else {
+ if (flags & FIGNORECASE)
+ txtype |= TX_CI;
+ zfs_log_symlink(zilog, tx, txtype, dzp, zp, name, link);
- zfs_inode_update(dzp);
- zfs_inode_update(zp);
+ zfs_inode_update(dzp);
+ zfs_inode_update(zp);
+ }
zfs_acl_ids_free(&acl_ids);
@@ -3871,10 +3905,14 @@ top:
zfs_dirent_unlock(dl);
- *ipp = ZTOI(zp);
+ if (error == 0) {
+ *ipp = ZTOI(zp);
- if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
- zil_commit(zilog, 0);
+ if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
+ zil_commit(zilog, 0);
+ } else {
+ iput(ZTOI(zp));
+ }
ZFS_EXIT(zfsvfs);
return (error);