Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "Scalability improvements when allocating inodes, and some
  miscellaneous bug fixes and cleanups"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: avoid Y2038 overflow in recently_deleted()
  ext4: fix fault handling when mounted with -o dax,ro
  ext4: fix quota inconsistency during orphan cleanup for read-only mounts
  ext4: fix incorrect quotaoff if the quota feature is enabled
  ext4: remove useless test and assignment in strtohash functions
  ext4: backward compatibility support for Lustre ea_inode implementation
  ext4: remove timebomb in ext4_decode_extra_time()
  ext4: use sizeof(*ptr)
  ext4: in ext4_seek_{hole,data}, return -ENXIO for negative offsets
  ext4: reduce lock contention in __ext4_new_inode
  ext4: cleanup goto next group
  ext4: do not unnecessarily allocate buffer in recently_deleted()

1 files changed, 60 insertions, 33 deletions

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 507bfb3344d4..71e93a23cec3 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -692,24 +692,25 @@ static int find_group_other(struct super_block *sb, struct inode *parent,
  * somewhat arbitrary...)
  */
 #define RECENTCY_MIN	5
-#define RECENTCY_DIRTY	30
+#define RECENTCY_DIRTY	300
 
 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
 {
 	struct ext4_group_desc	*gdp;
 	struct ext4_inode	*raw_inode;
 	struct buffer_head	*bh;
-	unsigned long		dtime, now;
-	int	inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
-	int	offset, ret = 0, recentcy = RECENTCY_MIN;
+	int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
+	int offset, ret = 0;
+	int recentcy = RECENTCY_MIN;
+	u32 dtime, now;
 
 	gdp = ext4_get_group_desc(sb, group, NULL);
 	if (unlikely(!gdp))
 		return 0;
 
-	bh = sb_getblk(sb, ext4_inode_table(sb, gdp) +
+	bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
 		       (ino / inodes_per_block));
-	if (unlikely(!bh) || !buffer_uptodate(bh))
+	if (!bh || !buffer_uptodate(bh))
 		/*
 		 * If the block is not in the buffer cache, then it
 		 * must have been written out.
@@ -718,18 +719,45 @@ static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino)
 
 	offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb);
 	raw_inode = (struct ext4_inode *) (bh->b_data + offset);
+
+	/* i_dtime is only 32 bits on disk, but we only care about relative
+	 * times in the range of a few minutes (i.e. long enough to sync a
+	 * recently-deleted inode to disk), so using the low 32 bits of the
+	 * clock (a 68 year range) is enough, see time_before32() */
 	dtime = le32_to_cpu(raw_inode->i_dtime);
-	now = get_seconds();
+	now = ktime_get_real_seconds();
 	if (buffer_dirty(bh))
 		recentcy += RECENTCY_DIRTY;
 
-	if (dtime && (dtime < now) && (now < dtime + recentcy))
+	if (dtime && time_before32(dtime, now) &&
+	    time_before32(now, dtime + recentcy))
 		ret = 1;
 out:
 	brelse(bh);
 	return ret;
 }
 
+static int find_inode_bit(struct super_block *sb, ext4_group_t group,
+			  struct buffer_head *bitmap, unsigned long *ino)
+{
+next:
+	*ino = ext4_find_next_zero_bit((unsigned long *)
+				       bitmap->b_data,
+				       EXT4_INODES_PER_GROUP(sb), *ino);
+	if (*ino >= EXT4_INODES_PER_GROUP(sb))
+		return 0;
+
+	if ((EXT4_SB(sb)->s_journal == NULL) &&
+	    recently_deleted(sb, group, *ino)) {
+		*ino = *ino + 1;
+		if (*ino < EXT4_INODES_PER_GROUP(sb))
+			goto next;
+		return 0;
+	}
+
+	return 1;
+}
+
 /*
  * There are two policies for allocating an inode.  If the new inode is
  * a directory, then a forward search is made for a block group with both
@@ -892,19 +920,13 @@ got_group:
 		/*
 		 * Check free inodes count before loading bitmap.
 		 */
-		if (ext4_free_inodes_count(sb, gdp) == 0) {
-			if (++group == ngroups)
-				group = 0;
-			continue;
-		}
+		if (ext4_free_inodes_count(sb, gdp) == 0)
+			goto next_group;
 
 		grp = ext4_get_group_info(sb, group);
 		/* Skip groups with already-known suspicious inode tables */
-		if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
-			if (++group == ngroups)
-				group = 0;
-			continue;
-		}
+		if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp))
+			goto next_group;
 
 		brelse(inode_bitmap_bh);
 		inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
@@ -912,27 +934,20 @@ got_group:
 		if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) ||
 		    IS_ERR(inode_bitmap_bh)) {
 			inode_bitmap_bh = NULL;
-			if (++group == ngroups)
-				group = 0;
-			continue;
+			goto next_group;
 		}
 
 repeat_in_this_group:
-		ino = ext4_find_next_zero_bit((unsigned long *)
-					      inode_bitmap_bh->b_data,
-					      EXT4_INODES_PER_GROUP(sb), ino);
-		if (ino >= EXT4_INODES_PER_GROUP(sb))
+		ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
+		if (!ret2)
 			goto next_group;
-		if (group == 0 && (ino+1) < EXT4_FIRST_INO(sb)) {
+
+		if (group == 0 && (ino + 1) < EXT4_FIRST_INO(sb)) {
 			ext4_error(sb, "reserved inode found cleared - "
 				   "inode=%lu", ino + 1);
-			continue;
-		}
-		if ((EXT4_SB(sb)->s_journal == NULL) &&
-		    recently_deleted(sb, group, ino)) {
-			ino++;
-			goto next_inode;
+			goto next_group;
 		}
+
 		if (!handle) {
 			BUG_ON(nblocks <= 0);
 			handle = __ext4_journal_start_sb(dir->i_sb, line_no,
@@ -952,11 +967,23 @@ repeat_in_this_group:
 		}
 		ext4_lock_group(sb, group);
 		ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
+		if (ret2) {
+			/* Someone already took the bit. Repeat the search
+			 * with lock held.
+			 */
+			ret2 = find_inode_bit(sb, group, inode_bitmap_bh, &ino);
+			if (ret2) {
+				ext4_set_bit(ino, inode_bitmap_bh->b_data);
+				ret2 = 0;
+			} else {
+				ret2 = 1; /* we didn't grab the inode */
+			}
+		}
 		ext4_unlock_group(sb, group);
 		ino++;		/* the inode bitmap is zero-based */
 		if (!ret2)
 			goto got; /* we grabbed the inode! */
-next_inode:
+
 		if (ino < EXT4_INODES_PER_GROUP(sb))
 			goto repeat_in_this_group;
 next_group: