From: Eric Sandeen <[email protected]>
If you do something like:
# touch foo
# tail -f foo &
# rm foo
# <take snapshot>
# <mount snapshot>
you'll panic, because ext3/4 tries to do orphan list processing on the
readonly snapshot device, and:
kernel: journal commit I/O error
kernel: Assertion failure in journal_flush_Rsmp_e2f189ce() at journal.c:1356: "!journal->j_checkpoint_transactions"
kernel: Kernel panic: Fatal exception
for a truly readonly underlying device, it's reasonable and necessary
to just skip orphan list processing.
Signed-off-by: Eric Sandeen <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---
fs/ext3/super.c | 6 ++++++
fs/ext4/super.c | 6 ++++++
2 files changed, 12 insertions(+)
diff -puN fs/ext3/super.c~ext3-4-dont-do-orphan-processing-on-readonly-devices fs/ext3/super.c
--- a/fs/ext3/super.c~ext3-4-dont-do-orphan-processing-on-readonly-devices
+++ a/fs/ext3/super.c
@@ -1264,6 +1264,12 @@ static void ext3_orphan_cleanup (struct
return;
}
+ if (bdev_read_only(sb->s_bdev)) {
+ printk(KERN_ERR "EXT3-fs: write access "
+ "unavailable, skipping orphan cleanup.\n");
+ return;
+ }
+
if (EXT3_SB(sb)->s_mount_state & EXT3_ERROR_FS) {
if (es->s_last_orphan)
jbd_debug(1, "Errors on filesystem, "
diff -puN fs/ext4/super.c~ext3-4-dont-do-orphan-processing-on-readonly-devices fs/ext4/super.c
--- a/fs/ext4/super.c~ext3-4-dont-do-orphan-processing-on-readonly-devices
+++ a/fs/ext4/super.c
@@ -1321,6 +1321,12 @@ static void ext4_orphan_cleanup (struct
return;
}
+ if (bdev_read_only(sb->s_bdev)) {
+ printk(KERN_ERR "EXT4-fs: write access "
+ "unavailable, skipping orphan cleanup.\n");
+ return;
+ }
+
if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
if (es->s_last_orphan)
jbd_debug(1, "Errors on filesystem, "
_