Extended attribute inodes have a link count of 1 but they are not
attached to any directories. When an xattr inode with zero ea
references is found, the remedy is to reconnect it to lost+found dir.
Since reconnect operation increments the link count, it would normally
become 2 but to avoid that, check_ea_inode() sets the link count to
zero in anticipation of reconnect operation. And it does it even when
e2fsck is invoked with -n option which causes a fatal e2fsck failure
as can be demonstrated with the following test script:
mke2fs -b 4096 -I 256 -F -O extent,ea_inode /dev/sdb 1G
mount /dev/sdb /mnt/sdb
touch /mnt/sdb/x
setfattr -n user.ie1 -v $(python -c "print 'v'*5000") /mnt/sdb/x
umount /dev/sdb
debugfs -w -R 'rm x' /dev/sdb
e2fsck -f -n /dev/sdb
In this case, e2fsck fails with the following error:
e2fsck 1.43.5-WIP (17-Feb-2017)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
ext2fs_write_inode: Attempt to write to filesystem opened read-only
while writing inode 13 in check_ea_inode
e2fsck: aborted
Setting link count to zero is not really required because e2fsck will
detect the discrepancy in link count and offer to fix it.
Signed-off-by: Tahsin Erdogan <tahsin@xxxxxxxxxx>
---
e2fsck/pass4.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)
diff --git a/e2fsck/pass4.c b/e2fsck/pass4.c
index 663f87ab59c0..b23347cdb6b0 100644
--- a/e2fsck/pass4.c
+++ b/e2fsck/pass4.c
@@ -122,17 +122,8 @@ static void check_ea_inode(e2fsck_t ctx, ext2_ino_t i,
if (ctx->ea_inode_refs)
ea_refcount_fetch(ctx->ea_inode_refs, i, &actual_refs);
- if (!actual_refs) {
- /*
- * There are no attribute references to the ea_inode.
- * Zero the link count so that when inode is linked to
- * lost+found it has correct link count.
- */
- inode->i_links_count = 0;
- e2fsck_write_inode(ctx, i, EXT2_INODE(inode), "check_ea_inode");
- ext2fs_icount_store(ctx->inode_link_info, i, 0);
+ if (!actual_refs)
return;
- }
/*
* There are some attribute references, link_counted is now considered
--
2.13.2.932.g7449e964c-goog
