Revert "Handle zap_add() failures in mixed ... "

This reverts commit cc63068e95.

Under certain circumstances this change can result in an ENOSPC
error when adding new files to a directory.  See #7401 for full
details.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Issue #7401
Closes #7416

include/sys/zap_leaf.h

@@ -46,15 +46,10 @@ struct zap_stats;
  * block size (1<<l->l_bs) - hash entry size (2) * number of hash
  * entries - header space (2*chunksize)
  */
-#define	ZAP_LEAF_NUMCHUNKS_BS(bs) \
+#define	ZAP_LEAF_NUMCHUNKS(l) \
-	(((1<<(bs)) - 2*ZAP_LEAF_HASH_NUMENTRIES_BS(bs)) / \
+	(((1<<(l)->l_bs) - 2*ZAP_LEAF_HASH_NUMENTRIES(l)) / \
 	ZAP_LEAF_CHUNKSIZE - 2)
 
-#define	ZAP_LEAF_NUMCHUNKS(l) (ZAP_LEAF_NUMCHUNKS_BS(((l)->l_bs)))
-
-#define	ZAP_LEAF_NUMCHUNKS_DEF \
-	(ZAP_LEAF_NUMCHUNKS_BS(fzap_default_block_shift))
-
 /*
  * The amount of space within the chunk available for the array is:
  * chunk size - space for type (1) - space for next pointer (2)
@@ -79,10 +74,8 @@ struct zap_stats;
  * which is less than block size / CHUNKSIZE (24) / minimum number of
  * chunks per entry (3).
  */
-#define	ZAP_LEAF_HASH_SHIFT_BS(bs) ((bs) - 5)
+#define	ZAP_LEAF_HASH_SHIFT(l) ((l)->l_bs - 5)
-#define	ZAP_LEAF_HASH_NUMENTRIES_BS(bs) (1 << ZAP_LEAF_HASH_SHIFT_BS(bs))
+#define	ZAP_LEAF_HASH_NUMENTRIES(l) (1 << ZAP_LEAF_HASH_SHIFT(l))
-#define	ZAP_LEAF_HASH_SHIFT(l) (ZAP_LEAF_HASH_SHIFT_BS(((l)->l_bs)))
-#define	ZAP_LEAF_HASH_NUMENTRIES(l) (ZAP_LEAF_HASH_NUMENTRIES_BS(((l)->l_bs)))
 
 /*
  * The chunks start immediately after the hash table.  The end of the

module/zfs/zap.c

@@ -819,19 +819,15 @@ 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);
@@ -855,29 +851,10 @@ 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:

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);
 

module/zfs/zap_micro.c

@@ -363,41 +363,6 @@ 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)
 {
@@ -1226,8 +1191,7 @@ 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,

module/zfs/zfs_dir.c

@@ -742,11 +742,7 @@ zfs_dirent(znode_t *zp, uint64_t mode)
 }
 
 /*
- * Link zp into dl.  Can fail in the following cases :
+ * Link zp into dl.  Can only fail if zp has been unlinked.
- * - 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)
@@ -780,24 +776,6 @@ 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,
@@ -835,6 +813,11 @@ 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);
 }
 

module/zfs/zfs_vnops.c

@@ -1443,22 +1443,10 @@ 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;
@@ -2049,18 +2037,13 @@ 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.
 	 */
-	error = zfs_link_create(dl, zp, tx, ZNEW);
+	(void) 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);
 
@@ -2070,7 +2053,6 @@ 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);
@@ -2080,14 +2062,10 @@ out:
 	if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
 		zil_commit(zilog, 0);
 
-	if (error != 0) {
+	zfs_inode_update(dzp);
-		iput(ZTOI(zp));
+	zfs_inode_update(zp);
-	} else {
-		zfs_inode_update(dzp);
-		zfs_inode_update(zp);
-	}
 	ZFS_EXIT(zfsvfs);
-	return (error);
+	return (0);
 }
 
 /*
@@ -3705,13 +3683,6 @@ 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);
 		}
 	}
 
@@ -3882,18 +3853,14 @@ top:
 	/*
 	 * Insert the new object into the directory.
 	 */
-	error = zfs_link_create(dl, zp, tx, ZNEW);
+	(void) 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);
+	if (flags & FIGNORECASE)
-		zfs_inode_update(zp);
+		txtype |= TX_CI;
-	}
+	zfs_log_symlink(zilog, tx, txtype, dzp, zp, name, link);
+
+	zfs_inode_update(dzp);
+	zfs_inode_update(zp);
 
 	zfs_acl_ids_free(&acl_ids);
 
@@ -3901,14 +3868,10 @@ top:
 
 	zfs_dirent_unlock(dl);
 
-	if (error == 0) {
+	*ipp = ZTOI(zp);
-		*ipp = ZTOI(zp);
 
-		if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
+	if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
-			zil_commit(zilog, 0);
+		zil_commit(zilog, 0);
-	} else {
-		iput(ZTOI(zp));
-	}
 
 	ZFS_EXIT(zfsvfs);
 	return (error);

tests/runfiles/linux.run

@@ -55,7 +55,7 @@ tags = ['functional', 'cachefile']
 # 'mixed_none_lookup', 'mixed_none_lookup_ci', 'mixed_none_delete',
 # 'mixed_formd_lookup', 'mixed_formd_lookup_ci', 'mixed_formd_delete']
 [tests/functional/casenorm]
-tests = ['case_all_values', 'norm_all_values', 'mixed_create_failure']
+tests = ['case_all_values', 'norm_all_values']
 tags = ['functional', 'casenorm']
 
 [tests/functional/chattr]

tests/zfs-tests/tests/functional/casenorm/Makefile.am

@@ -9,7 +9,6 @@ dist_pkgdata_SCRIPTS = \
 	insensitive_formd_lookup.ksh \
 	insensitive_none_delete.ksh \
 	insensitive_none_lookup.ksh \
-	mixed_create_failure.ksh \
 	mixed_formd_delete.ksh \
 	mixed_formd_lookup_ci.ksh \
 	mixed_formd_lookup.ksh \

tests/zfs-tests/tests/functional/casenorm/mixed_create_failure.ksh

@@ -1,136 +0,0 @@
-#!/bin/ksh -p
-#
-#
-# This file and its contents are supplied under the terms of the
-# Common Development and Distribution License ("CDDL"), version 1.0.
-# You may only use this file in accordance with the terms of version
-# 1.0 of the CDDL.
-#
-# A full copy of the text of the CDDL should have accompanied this
-# source.  A copy of the CDDL is also available via the Internet at
-# http://www.illumos.org/license/CDDL.
-#
-#
-# Copyright 2018 Nutanix Inc.  All rights reserved.
-#
-
-. $STF_SUITE/tests/functional/casenorm/casenorm.kshlib
-
-# DESCRIPTION:
-# For the filesystem with casesensitivity=mixed, normalization=none,
-# when multiple files with the same name (differing only in case) are created,
-# the number of files is limited to what can fit in a fatzap leaf-block.
-# And beyond that, it fails with ENOSPC.
-#
-# Ensure that the create/rename operations fail gracefully and not trigger an
-# ASSERT.
-#
-# STRATEGY:
-# Repeat the below steps for objects: files, directories, symlinks and hardlinks
-# 1. Create objects with same name but varying in case.
-#    E.g. 'abcdefghijklmnop', 'Abcdefghijklmnop', 'ABcdefghijklmnop' etc.
-#    The create should fail with ENOSPC.
-# 2. Create an object with name 'tmp_obj' and try to rename it to name that we
-#    failed to add in step 1 above.
-#    This should fail as well.
-
-verify_runnable "global"
-
-function cleanup
-{
-        destroy_testfs
-}
-
-log_onexit cleanup
-log_assert "With mixed mode: ensure create fails with ENOSPC beyond a certain limit"
-
-create_testfs "-o casesensitivity=mixed -o normalization=none"
-
-# Different object types
-obj_type=('file' 'dir' 'symlink' 'hardlink')
-
-# Commands to create different object types
-typeset -A ops
-ops['file']='touch'
-ops['dir']='mkdir'
-ops['symlink']='ln -s'
-ops['hardlink']='ln'
-
-# This function tests the following for a give object type :
-# - Create multiple objects with the same name (varying only in case).
-#   Ensure that it eventually fails once the leaf-block limit is exceeded.
-# - Create another object with a different name. And attempt rename it to the
-#   name (for which the create had failed in the previous step).
-#   This should fail as well.
-# Args :
-#   $1 - object type (file/dir/symlink/hardlink)
-#   $2 - test directory
-#
-function test_ops
-{
-	typeset obj_type=$1
-	typeset testdir=$2
-
-	target_obj='target-file'
-
-	op="${ops[$obj_type]}"
-
-	log_note "The op : $op"
-	log_note "testdir=$testdir obj_type=$obj_type"
-
-	test_path="$testdir/$obj_type"
-	mkdir $test_path
-	log_note "Created test dir $test_path"
-
-	if [[ $obj_type = "symlink" || $obj_type = "hardlink" ]]; then
-		touch $test_path/$target_obj
-		log_note "Created target: $test_path/$target_obj"
-		op="$op $test_path/$target_obj"
-	fi
-
-	log_note "op : $op"
-	names='{a,A}{b,B}{c,C}{d,D}{e,E}{f,F}{g,G}{h,H}{i,I}{j,J}{k,K}{l,L}'
-	for name in $names; do
-		cmd="$op $test_path/$name"
-		out=$($cmd 2>&1)
-		ret=$?
-		log_note "cmd: $cmd ret: $ret out=$out"
-		if (($ret != 0)); then
-			if [[ $out = *@(No space left on device)* ]]; then
-				save_name="$test_path/$name"
-				break;
-			else
-				log_err "$cmd failed with unexpected error : $out"
-			fi
-		fi
-	done
-
-	log_note 'Test rename \"sample_name\" rename'
-	TMP_OBJ="$test_path/tmp_obj"
-	cmd="$op $TMP_OBJ"
-	out=$($cmd 2>&1)
-	ret=$?
-	if (($ret != 0)); then
-		log_err "cmd:$cmd failed out:$out"
-	fi
-
-	# Now, try to rename the tmp_obj to the name which we failed to add earlier.
-	# This should fail as well.
-	out=$(mv $TMP_OBJ $save_name 2>&1)
-	ret=$?
-	if (($ret != 0)); then
-		if [[ $out = *@(No space left on device)* ]]; then
-			log_note "$cmd failed as expected : $out"
-		else
-			log_err "$cmd failed with : $out"
-		fi
-	fi
-}
-
-for obj_type in ${obj_type[*]};
-do
-	log_note "Testing create of $obj_type"
-	test_ops $obj_type $TESTDIR
-done
-
-log_pass "Mixed mode FS: Ops on large number of colliding names fail gracefully"