Re: MTD : Kernel oops when remounting ubifs as read/write

Artem Bityutskiy
2013-03-12T11:24:20Z

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On Mon, 2013-03-04 at 16:42 +0000, Mark Jackson wrote:
> I'm encountering an oops when remounting my ubifs volume as read/write.
>
> # mount -o remount,rw /
> [ 89.434974] UBIFS assert failed in ubifs_write_node at 869 (pid 628)
> [ 89.442122] [<c001b124>] (unwind_backtrace+0x0/0xf0) from [<c01ad7d4>] (ubifs_write_node+0x180/0x1c4)
> [ 89.451896] [<c01ad7d4>] (ubifs_write_node+0x180/0x1c4) from [<c01b3878>] (ubifs_write_master+0x9c/0x134)
> [ 89.462018] [<c01b3878>] (ubifs_write_master+0x9c/0x134) from [<c01a79a4>] (ubifs_remount_fs+0x5d4/0x7f8)
> [ 89.472133] [<c01a79a4>] (ubifs_remount_fs+0x5d4/0x7f8) from [<c010dbf4>] (do_remount_sb+0x98/0x16c)
> [ 89.481790] [<c010dbf4>] (do_remount_sb+0x98/0x16c) from [<c0128268>] (do_mount+0x830/0x888)
> [ 89.490708] [<c0128268>] (do_mount+0x830/0x888) from [<c0128344>] (sys_mount+0x84/0xb8)
> [ 89.499178] [<c0128344>] (sys_mount+0x84/0xb8) from [<c0013800>] (ret_fast_syscall+0x0/0x3c)
> [ 89.510997] UBIFS assert failed in ubifs_write_node at 869 (pid 628)
> [ 89.517884] [<c001b124>] (unwind_backtrace+0x0/0xf0) from [<c01ad7d4>] (ubifs_write_node+0x180/0x1c4)
> [ 89.527641] [<c01ad7d4>] (ubifs_write_node+0x180/0x1c4) from [<c01b38b4>] (ubifs_write_master+0xd8/0x134)
> [ 89.537760] [<c01b38b4>] (ubifs_write_master+0xd8/0x134) from [<c01a79a4>] (ubifs_remount_fs+0x5d4/0x7f8)
> [ 89.547869] [<c01a79a4>] (ubifs_remount_fs+0x5d4/0x7f8) from [<c010dbf4>] (do_remount_sb+0x98/0x16c)
> [ 89.557526] [<c010dbf4>] (do_remount_sb+0x98/0x16c) from [<c0128268>] (do_mount+0x830/0x888)
> [ 89.566435] [<c0128268>] (do_mount+0x830/0x888) from [<c0128344>] (sys_mount+0x84/0xb8)
> [ 89.574905] [<c0128344>] (sys_mount+0x84/0xb8) from [<c0013800>] (ret_fast_syscall+0x0/0x3c)
> [ 89.585939] UBIFS: start fixing up free space
> [ 89.592237] UBIFS: background thread "ubifs_bgt0_0" started, PID 629
> [ 91.419951] UBIFS: free space fixup complete
> #
>
> If it's any help, if the remount is put into my inittab, I don't get any oops.

Would you please try this patch (also attached):

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index ac838b8..9791b3c 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1568,6 +1568,12 @@ static int ubifs_remount_rw(struct ubifs_info *c)
c->remounting_rw = 1;
c->ro_mount = 0;

+ if (c->space_fixup) {
+ err = ubifs_fixup_free_space(c);
+ if (err)
+ goto out;
+ }
+
err = check_free_space(c);
if (err)
goto out;
@@ -1684,12 +1690,6 @@ static int ubifs_remount_rw(struct ubifs_info *c)
err = dbg_check_space_info(c);
}

- if (c->space_fixup) {
- err = ubifs_fixup_free_space(c);
- if (err)
- goto out;
- }
-
mutex_unlock(&c->umount_mutex);
return err;

--
Best Regards,
Artem Bityutskiy

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diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index ac838b8..9791b3c 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1568,6 +1568,12 @@ static int ubifs_remount_rw(struct ubifs_info *c)
c->remounting_rw = 1;
c->ro_mount = 0;

+ if (c->space_fixup) {
+ err = ubifs_fixup_free_space(c);
+ if (err)
+ goto out;
+ }
+
err = check_free_space(c);
if (err)
goto out;
@@ -1684,12 +1690,6 @@ static int ubifs_remount_rw(struct ubifs_info *c)
err = dbg_check_space_info(c);
}

- if (c->space_fixup) {
- err = ubifs_fixup_free_space(c);
- if (err)
- goto out;
- }
-
mutex_unlock(&c->umount_mutex);
return err;