From: Josh Triplett josh@joshtriplett.org
[ Upstream commit 426d15ad11419066f7042ffa8fbf1b5c21a1ecbe ]
On a read-only filesystem, we won't invoke the block allocator, so we don't need to prefetch the block bitmaps.
This avoids starting and running the ext4lazyinit thread at all on a system with no read-write ext4 filesystems (for instance, a container VM with read-only filesystems underneath an overlayfs).
Fixes: 21175ca434c5 ("ext4: make prefetch_block_bitmaps default") Signed-off-by: Josh Triplett josh@joshtriplett.org Reviewed-by: Lukas Czerner lczerner@redhat.com Link: https://lore.kernel.org/r/48b41da1498fcac3287e2e06b660680646c1c050.165932397... Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ext4/super.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 323dbcfd285c..091db733834e 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3962,9 +3962,9 @@ int ext4_register_li_request(struct super_block *sb, goto out; }
- if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) && - (first_not_zeroed == ngroups || sb_rdonly(sb) || - !test_opt(sb, INIT_INODE_TABLE))) + if (sb_rdonly(sb) || + (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) && + (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE)))) goto out;
elr = ext4_li_request_new(sb, first_not_zeroed);