btrfs: add readonly flag
setting the readonly flag prevents writes in case an error is detected
Signed-off-by: Arne Jansen <sensille@gmx.net>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b7373b1..ee90466 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2657,7 +2657,7 @@
/* scrub.c */
int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end,
- struct btrfs_scrub_progress *progress);
+ struct btrfs_scrub_progress *progress, int readonly);
int btrfs_scrub_pause(struct btrfs_root *root);
int btrfs_scrub_pause_super(struct btrfs_root *root);
int btrfs_scrub_continue(struct btrfs_root *root);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 205cd01..f0a74f0 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2547,7 +2547,7 @@
return PTR_ERR(sa);
ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end,
- &sa->progress);
+ &sa->progress, sa->flags & BTRFS_SCRUB_READONLY);
if (copy_to_user(arg, sa, sizeof(*sa)))
ret = -EFAULT;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 1a638ce..e5e0ee2c 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -81,6 +81,7 @@
* Intermittent error. */
};
+#define BTRFS_SCRUB_READONLY 1
struct btrfs_ioctl_scrub_args {
__u64 devid; /* in */
__u64 start; /* in */
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 6a50801..a31f2a9 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -42,7 +42,6 @@
* - In case of a read error on files with nodatasum, map the file and read
* the extent to trigger a writeback of the good copy
* - track and record media errors, throw out bad devices
- * - add a readonly mode
* - add a mode to also read unallocated space
* - make the prefetch cancellable
*/
@@ -99,6 +98,7 @@
u16 csum_size;
struct list_head csum_list;
atomic_t cancel_req;
+ int readonly;
/*
* statistics
*/
@@ -329,14 +329,16 @@
if (i == multi->num_stripes)
goto uncorrectable;
- /*
- * bi_io_vec[ix].bv_page now contains good data, write it back
- */
- if (scrub_fixup_io(WRITE, sdev->dev->bdev,
- (sbio->physical + ix * PAGE_SIZE) >> 9,
- sbio->bio->bi_io_vec[ix].bv_page)) {
- /* I/O-error, writeback failed, give up */
- goto uncorrectable;
+ if (!sdev->readonly) {
+ /*
+ * bi_io_vec[ix].bv_page now contains good data, write it back
+ */
+ if (scrub_fixup_io(WRITE, sdev->dev->bdev,
+ (sbio->physical + ix * PAGE_SIZE) >> 9,
+ sbio->bio->bi_io_vec[ix].bv_page)) {
+ /* I/O-error, writeback failed, give up */
+ goto uncorrectable;
+ }
}
kfree(multi);
@@ -1156,7 +1158,7 @@
int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end,
- struct btrfs_scrub_progress *progress)
+ struct btrfs_scrub_progress *progress, int readonly)
{
struct scrub_dev *sdev;
struct btrfs_fs_info *fs_info = root->fs_info;
@@ -1209,6 +1211,7 @@
scrub_workers_put(root);
return PTR_ERR(sdev);
}
+ sdev->readonly = readonly;
dev->scrub_device = sdev;
atomic_inc(&fs_info->scrubs_running);