We are keeping track of how many extents we need to reserve properly based on
the amount we want to write, but we were still incrementing outstanding_extents
if we wrote less than what we requested. We need to fix this logic to only do
this if we request less than MAX_EXTENT_SIZE or if we write less than
MAX_EXTENT_SIZE when we request an amount larger than MAX_EXTENT_SIZE. This
fixes the problem Filipe reported with generic/300. Thanks,
Reported-by: Filipe Manana <fdmanana@xxxxxxxx>
Signed-off-by: Josef Bacik <jbacik@xxxxxx>
---
fs/btrfs/inode.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 156d0f5..f6d2c56 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7387,7 +7387,24 @@ unlock:
if (start + len > i_size_read(inode))
i_size_write(inode, start + len);
- if (len < orig_len) {
+ /*
+ * direct_io can send down chunks > BTRFS_MAX_EXTENT_SIZE, so we
+ * don't want to jack up outstanding_extents if we're just
+ * allocating the largest extent we can for a range that we've
+ * already reserved the approriate number of outstanding_extents
+ * for.
+ *
+ * So if orig_len <= BTRFS_MAX_EXTENT_SIZE and our allocated len
+ * is less than orig_len then we know we're going to end up with
+ * more extents than we reserved.
+ *
+ * If orig_len > BTRFS_MAX_EXTENT_SIZE but we weren't able to
+ * allocate a BTRFS_MAX_EXTENT_SIZE extent then we know we have
+ * to add another outstanding extent.
+ */
+ if (len < orig_len &&
+ (orig_len <= BTRFS_MAX_EXTENT_SIZE ||
+ len < BTRFS_MAX_EXTENT_SIZE)) {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents++;
spin_unlock(&BTRFS_I(inode)->lock);
--
1.8.3.1
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