[PATCH 4.19 094/140] ext4: Fix credit estimate for final inode freeing

[Greg Kroah-Hartman]

From: Jan Kara <jack@xxxxxxx>

commit 65db869c754e7c271691dd5feabf884347e694f5 upstream.

Estimate for the number of credits needed for final freeing of inode in
ext4_evict_inode() was to small. We may modify 4 blocks (inode & sb for
orphan deletion, bitmap & group descriptor for inode freeing) and not
just 3.

[ Fixed minor whitespace nit. -- TYT ]

Fixes: e50e5129f384 ("ext4: xattr-in-inode support")
CC: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jan Kara <jack@xxxxxxx>
Link: https://lore.kernel.org/r/20191105164437.32602-6-jack@xxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/ext4/inode.c |   13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -196,7 +196,12 @@ void ext4_evict_inode(struct inode *inod
 {
 	handle_t *handle;
 	int err;
-	int extra_credits = 3;
+	/*
+	 * Credits for final inode cleanup and freeing:
+	 * sb + inode (ext4_orphan_del()), block bitmap, group descriptor
+	 * (xattr block freeing), bitmap, group descriptor (inode freeing)
+	 */
+	int extra_credits = 6;
 	struct ext4_xattr_inode_array *ea_inode_array = NULL;
 
 	trace_ext4_evict_inode(inode);
@@ -252,8 +257,12 @@ void ext4_evict_inode(struct inode *inod
 	if (!IS_NOQUOTA(inode))
 		extra_credits += EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb);
 
+	/*
+	 * Block bitmap, group descriptor, and inode are accounted in both
+	 * ext4_blocks_for_truncate() and extra_credits. So subtract 3.
+	 */
 	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE,
-				 ext4_blocks_for_truncate(inode)+extra_credits);
+			 ext4_blocks_for_truncate(inode) + extra_credits - 3);
 	if (IS_ERR(handle)) {
 		ext4_std_error(inode->i_sb, PTR_ERR(handle));
 		/*