block: use struct parsed_partitions *state universally in partition check code

Make the following changes to partition check code.

* Add ->bdev to struct parsed_partitions.

* Introduce read_part_sector() which is a simple wrapper around
  read_dev_sector() which takes struct parsed_partitions *state
  instead of @bdev.

* For functions which used to take @state and @bdev, drop @bdev.  For
  functions which used to take @bdev, replace it with @state.

* While updating, drop superflous checks on NULL state/bdev in ldm.c.

This cleans up the API a bit and enables better handling of IO errors
during partition check as the generic partition check code now has
much better visibility into what went wrong in the low level code
paths.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 4f1fee0355a..a19995c6f6a 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -45,7 +45,7 @@ extern void md_autodetect_dev(dev_t dev);
 
 int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/
 
-static int (*check_part[])(struct parsed_partitions *, struct block_device *) = {
+static int (*check_part[])(struct parsed_partitions *) = {
         /*
          * Probe partition formats with tables at disk address 0
          * that also have an ADFS boot block at 0xdc0.
@@ -165,6 +165,7 @@ check_partition(struct gendisk *hd, struct block_device *bdev)
         if (!state)
                 return NULL;
 
+        state->bdev = bdev;
         disk_name(hd, 0, state->name);
         printk(KERN_INFO " %s:", state->name);
         if (isdigit(state->name[strlen(state->name)-1]))
@@ -174,7 +175,7 @@ check_partition(struct gendisk *hd, struct block_device *bdev)
         i = res = err = 0;
         while (!res && check_part[i]) {
                 memset(&state->parts, 0, sizeof(state->parts));
-                res = check_part[i++](state, bdev);
+                res = check_part[i++](state);
                 if (res < 0) {
                         /* We have hit an I/O error which we don't report now.
                         * But record it, and let the others do their job.