diff options
| author | Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com> | 2012-07-14 14:19:46 +0300 |
|---|---|---|
| committer | Artem Bityutskiy <artem.bityutskiy@linux.intel.com> | 2012-07-20 10:27:25 +0300 |
| commit | 06bef9451a4c5ad882cd15fd7a0df9890c0249f3 (patch) | |
| tree | abd269a573e5ffce8b7e92c39cc3000ca1ecb944 /fs | |
| parent | 782759b9f5f5223e0962af60c3457c912fab755f (diff) | |
| download | lwn-06bef9451a4c5ad882cd15fd7a0df9890c0249f3.tar.gz lwn-06bef9451a4c5ad882cd15fd7a0df9890c0249f3.zip | |
UBIFS: add debugfs knob to switch to R/O mode
This patch adds another debugfs knob which switches UBIFS to R/O mode.
I needed it while trying to reproduce the 'first log node is not CS node'
bug. Without this debugfs knob you have to perform a power cut to repruduce
the bug. The knob is named 'ro_error' and all it does is it sets the
'ro_error' UBIFS flag which makes UBIFS disallow any further writes - even
write-back will fail with -EROFS. Useful for debugging.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ubifs/debug.c | 11 | ||||
| -rw-r--r-- | fs/ubifs/debug.h | 5 |
2 files changed, 16 insertions, 0 deletions
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c index 92df3b081539..bb3167257aab 100644 --- a/fs/ubifs/debug.c +++ b/fs/ubifs/debug.c @@ -2802,6 +2802,8 @@ static ssize_t dfs_file_read(struct file *file, char __user *u, size_t count, val = d->chk_fs; else if (dent == d->dfs_tst_rcvry) val = d->tst_rcvry; + else if (dent == d->dfs_ro_error) + val = c->ro_error; else return -EINVAL; @@ -2885,6 +2887,8 @@ static ssize_t dfs_file_write(struct file *file, const char __user *u, d->chk_fs = val; else if (dent == d->dfs_tst_rcvry) d->tst_rcvry = val; + else if (dent == d->dfs_ro_error) + c->ro_error = !!val; else return -EINVAL; @@ -2996,6 +3000,13 @@ int dbg_debugfs_init_fs(struct ubifs_info *c) goto out_remove; d->dfs_tst_rcvry = dent; + fname = "ro_error"; + dent = debugfs_create_file(fname, S_IRUSR | S_IWUSR, d->dfs_dir, c, + &dfs_fops); + if (IS_ERR_OR_NULL(dent)) + goto out_remove; + d->dfs_ro_error = dent; + return 0; out_remove: diff --git a/fs/ubifs/debug.h b/fs/ubifs/debug.h index 486a8e024fb6..8b8cc4e945f4 100644 --- a/fs/ubifs/debug.h +++ b/fs/ubifs/debug.h @@ -79,6 +79,10 @@ typedef int (*dbg_znode_callback)(struct ubifs_info *c, * @dfs_chk_lprops: debugfs knob to enable UBIFS LEP properties extra checks * @dfs_chk_fs: debugfs knob to enable UBIFS contents extra checks * @dfs_tst_rcvry: debugfs knob to enable UBIFS recovery testing + * @dfs_ro_error: debugfs knob to switch UBIFS to R/O mode (different to + * re-mounting to R/O mode because it does not flush any buffers + * and UBIFS just starts returning -EROFS on all write + * operations) */ struct ubifs_debug_info { struct ubifs_zbranch old_zroot; @@ -122,6 +126,7 @@ struct ubifs_debug_info { struct dentry *dfs_chk_lprops; struct dentry *dfs_chk_fs; struct dentry *dfs_tst_rcvry; + struct dentry *dfs_ro_error; }; /** |