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| author | Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> | 2010-08-13 07:42:24 +0400 |
|---|---|---|
| committer | Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> | 2010-08-16 06:08:36 +0400 |
| commit | af4e36318edb848fcc0a8d5f75000ca00cdc7595 (patch) | |
| tree | c23ce8d1839f31ec4c472da184f16542a59752dd /fs/nilfs2 | |
| parent | da5cabf80e2433131bf0ed8993abc0f7ea618c73 (diff) | |
| download | linux-af4e36318edb848fcc0a8d5f75000ca00cdc7595.tar.xz | |
nilfs2: fix list corruption after ifile creation failure
If nilfs_attach_checkpoint() gets a memory allocation failure during
creation of ifile, it will return without removing nilfs_sb_info
struct from ns_supers list. When a concurrently mounted snapshot is
unmounted or another new snapshot is mounted after that, this causes
kernel oops as below:
> BUG: unable to handle kernel NULL pointer dereference at (null)
> IP: [<f83662ff>] nilfs_find_sbinfo+0x74/0xa4 [nilfs2]
> *pde = 00000000
> Oops: 0000 [#1] SMP
<snip>
> Call Trace:
> [<f835dc29>] ? nilfs_get_sb+0x165/0x532 [nilfs2]
> [<c1173c87>] ? ida_get_new_above+0x16d/0x187
> [<c109a7f8>] ? alloc_vfsmnt+0x7e/0x10a
> [<c1070790>] ? kstrdup+0x2c/0x40
> [<c1089041>] ? vfs_kern_mount+0x96/0x14e
> [<c108913d>] ? do_kern_mount+0x32/0xbd
> [<c109b331>] ? do_mount+0x642/0x6a1
> [<c101a415>] ? do_page_fault+0x0/0x2d1
> [<c1099c00>] ? copy_mount_options+0x80/0xe2
> [<c10705d8>] ? strndup_user+0x48/0x67
> [<c109b3f1>] ? sys_mount+0x61/0x90
> [<c10027cc>] ? sysenter_do_call+0x12/0x22
This fixes the problem.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: stable@kernel.org
Diffstat (limited to 'fs/nilfs2')
| -rw-r--r-- | fs/nilfs2/super.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index 1fa86b9df73b..bee60c04109a 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -400,9 +400,10 @@ int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno) list_add(&sbi->s_list, &nilfs->ns_supers); up_write(&nilfs->ns_super_sem); + err = -ENOMEM; sbi->s_ifile = nilfs_ifile_new(sbi, nilfs->ns_inode_size); if (!sbi->s_ifile) - return -ENOMEM; + goto delist; down_read(&nilfs->ns_segctor_sem); err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp, @@ -433,6 +434,7 @@ int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno) nilfs_mdt_destroy(sbi->s_ifile); sbi->s_ifile = NULL; + delist: down_write(&nilfs->ns_super_sem); list_del_init(&sbi->s_list); up_write(&nilfs->ns_super_sem); |