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authorJosh Triplett <josh@joshtriplett.org>2021-06-07 12:15:24 -0700
committerTheodore Ts'o <tytso@mit.edu>2021-06-24 10:22:36 -0400
commitb1489186cc8391e0c1e342f9fbc3eedf6b944c61 (patch)
tree90bcfdd13f559812a7e3ce408a3f0de44f4bbf63 /fs/ext4
parente9f9f61d0cdcb7f0b0b5feb2d84aa1c5894751f3 (diff)
ext4: add check to prevent attempting to resize an fs with sparse_super2
The in-kernel ext4 resize code doesn't support filesystem with the sparse_super2 feature. It fails with errors like this and doesn't finish the resize: EXT4-fs (loop0): resizing filesystem from 16640 to 7864320 blocks EXT4-fs warning (device loop0): verify_reserved_gdb:760: reserved GDT 2 missing grp 1 (32770) EXT4-fs warning (device loop0): ext4_resize_fs:2111: error (-22) occurred during file system resize EXT4-fs (loop0): resized filesystem to 2097152 To reproduce: mkfs.ext4 -b 4096 -I 256 -J size=32 -E resize=$((256*1024*1024)) -O sparse_super2 ext4.img 65M truncate -s 30G ext4.img mount ext4.img /mnt python3 -c 'import fcntl, os, struct ; fd = os.open("/mnt", os.O_RDONLY | os.O_DIRECTORY) ; fcntl.ioctl(fd, 0x40086610, struct.pack("Q", 30 * 1024 * 1024 * 1024 // 4096), False) ; os.close(fd)' dmesg | tail e2fsck ext4.img The userspace resize2fs tool has a check for this case: it checks if the filesystem has sparse_super2 set and if the kernel provides /sys/fs/ext4/features/sparse_super2. However, the former check requires manually reading and parsing the filesystem superblock. Detect this case in ext4_resize_begin and error out early with a clear error message. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Link: https://lore.kernel.org/r/74b8ae78405270211943cd7393e65586c5faeed1.1623093259.git.josh@joshtriplett.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/resize.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index d13bb9e76482..fc885914c88a 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -78,6 +78,10 @@ int ext4_resize_begin(struct super_block *sb)
ext4_msg(sb, KERN_ERR, "Online resizing not supported with bigalloc");
return -EOPNOTSUPP;
}
+ if (ext4_has_feature_sparse_super2(sb)) {
+ ext4_msg(sb, KERN_ERR, "Online resizing not supported with sparse_super2");
+ return -EOPNOTSUPP;
+ }
if (test_and_set_bit_lock(EXT4_FLAGS_RESIZING,
&EXT4_SB(sb)->s_ext4_flags))