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, 44 insertions, 45 deletions

diff --git a/fs/partitions/ldm.c b/fs/partitions/ldm.c
index 8652fb99e962..3ceca05b668c 100644
--- a/fs/partitions/ldm.c
+++ b/fs/partitions/ldm.c
@@ -309,7 +309,7 @@ static bool ldm_compare_tocblocks (const struct tocblock *toc1,
 
 /**
  * ldm_validate_privheads - Compare the primary privhead with its backups
- * @bdev:  Device holding the LDM Database
+ * @state: Partition check state including device holding the LDM Database
  * @ph1:   Memory struct to fill with ph contents
  *
  * Read and compare all three privheads from disk.
@@ -321,8 +321,8 @@ static bool ldm_compare_tocblocks (const struct tocblock *toc1,
  * Return:  'true'   Success
  *          'false'  Error
  */
-static bool ldm_validate_privheads (struct block_device *bdev,
-                                    struct privhead *ph1)
+static bool ldm_validate_privheads(struct parsed_partitions *state,
+                                   struct privhead *ph1)
 {
         static const int off[3] = { OFF_PRIV1, OFF_PRIV2, OFF_PRIV3 };
         struct privhead *ph[3] = { ph1 };
@@ -332,7 +332,7 @@ static bool ldm_validate_privheads (struct block_device *bdev,
         long num_sects;
         int i;
 
-        BUG_ON (!bdev || !ph1);
+        BUG_ON (!state || !ph1);
 
         ph[1] = kmalloc (sizeof (*ph[1]), GFP_KERNEL);
         ph[2] = kmalloc (sizeof (*ph[2]), GFP_KERNEL);
@@ -346,8 +346,8 @@ static bool ldm_validate_privheads (struct block_device *bdev,
 
         /* Read and parse privheads */
         for (i = 0; i < 3; i++) {
-                data = read_dev_sector (bdev,
-                        ph[0]->config_start + off[i], &sect);
+                data = read_part_sector(state, ph[0]->config_start + off[i],
+                                        &sect);
                 if (!data) {
                         ldm_crit ("Disk read failed.");
                         goto out;
@@ -363,7 +363,7 @@ static bool ldm_validate_privheads (struct block_device *bdev,
                 }
         }
 
-        num_sects = bdev->bd_inode->i_size >> 9;
+        num_sects = state->bdev->bd_inode->i_size >> 9;
 
         if ((ph[0]->config_start > num_sects) ||
            ((ph[0]->config_start + ph[0]->config_size) > num_sects)) {
@@ -397,20 +397,20 @@ out:
 
 /**
  * ldm_validate_tocblocks - Validate the table of contents and its backups
- * @bdev:  Device holding the LDM Database
- * @base:  Offset, into @bdev, of the database
+ * @state: Partition check state including device holding the LDM Database
+ * @base:  Offset, into @state->bdev, of the database
  * @ldb:   Cache of the database structures
  *
  * Find and compare the four tables of contents of the LDM Database stored on
- * @bdev and return the parsed information into @toc1.
+ * @state->bdev and return the parsed information into @toc1.
  *
  * The offsets and sizes of the configs are range-checked against a privhead.
  *
  * Return:  'true'   @toc1 contains validated TOCBLOCK info
  *          'false'  @toc1 contents are undefined
  */
-static bool ldm_validate_tocblocks(struct block_device *bdev,
-        unsigned long base, struct ldmdb *ldb)
+static bool ldm_validate_tocblocks(struct parsed_partitions *state,
+                                   unsigned long base, struct ldmdb *ldb)
 {
         static const int off[4] = { OFF_TOCB1, OFF_TOCB2, OFF_TOCB3, OFF_TOCB4};
         struct tocblock *tb[4];
@@ -420,7 +420,7 @@ static bool ldm_validate_tocblocks(struct block_device *bdev,
         int i, nr_tbs;
         bool result = false;
 
-        BUG_ON(!bdev || !ldb);
+        BUG_ON(!state || !ldb);
         ph = &ldb->ph;
         tb[0] = &ldb->toc;
         tb[1] = kmalloc(sizeof(*tb[1]) * 3, GFP_KERNEL);
@@ -437,7 +437,7 @@ static bool ldm_validate_tocblocks(struct block_device *bdev,
          * skip any that fail as long as we get at least one valid TOCBLOCK.
          */
         for (nr_tbs = i = 0; i < 4; i++) {
-                data = read_dev_sector(bdev, base + off[i], &sect);
+                data = read_part_sector(state, base + off[i], &sect);
                 if (!data) {
                         ldm_error("Disk read failed for TOCBLOCK %d.", i);
                         continue;
@@ -473,7 +473,7 @@ err:
 
 /**
  * ldm_validate_vmdb - Read the VMDB and validate it
- * @bdev:  Device holding the LDM Database
+ * @state: Partition check state including device holding the LDM Database
  * @base:  Offset, into @bdev, of the database
  * @ldb:   Cache of the database structures
  *
@@ -483,8 +483,8 @@ err:
  * Return:  'true'   @ldb contains validated VBDB info
  *          'false'  @ldb contents are undefined
  */
-static bool ldm_validate_vmdb (struct block_device *bdev, unsigned long base,
-                               struct ldmdb *ldb)
+static bool ldm_validate_vmdb(struct parsed_partitions *state,
+                              unsigned long base, struct ldmdb *ldb)
 {
         Sector sect;
         u8 *data;
@@ -492,12 +492,12 @@ static bool ldm_validate_vmdb (struct block_device *bdev, unsigned long base,
         struct vmdb *vm;
         struct tocblock *toc;
 
-        BUG_ON (!bdev || !ldb);
+        BUG_ON (!state || !ldb);
 
         vm  = &ldb->vm;
         toc = &ldb->toc;
 
-        data = read_dev_sector (bdev, base + OFF_VMDB, &sect);
+        data = read_part_sector(state, base + OFF_VMDB, &sect);
         if (!data) {
                 ldm_crit ("Disk read failed.");
                 return false;
@@ -534,21 +534,21 @@ out:
 
 /**
  * ldm_validate_partition_table - Determine whether bdev might be a dynamic disk
- * @bdev:  Device holding the LDM Database
+ * @state: Partition check state including device holding the LDM Database
  *
  * This function provides a weak test to decide whether the device is a dynamic
  * disk or not.  It looks for an MS-DOS-style partition table containing at
  * least one partition of type 0x42 (formerly SFS, now used by Windows for
  * dynamic disks).
  *
- * N.B.  The only possible error can come from the read_dev_sector and that is
+ * N.B.  The only possible error can come from the read_part_sector and that is
  *       only likely to happen if the underlying device is strange.  If that IS
  *       the case we should return zero to let someone else try.
  *
- * Return:  'true'   @bdev is a dynamic disk
- *          'false'  @bdev is not a dynamic disk, or an error occurred
+ * Return:  'true'   @state->bdev is a dynamic disk
+ *          'false'  @state->bdev is not a dynamic disk, or an error occurred
  */
-static bool ldm_validate_partition_table (struct block_device *bdev)
+static bool ldm_validate_partition_table(struct parsed_partitions *state)
 {
         Sector sect;
         u8 *data;
@@ -556,9 +556,9 @@ static bool ldm_validate_partition_table (struct block_device *bdev)
         int i;
         bool result = false;
 
-        BUG_ON (!bdev);
+        BUG_ON(!state);
 
-        data = read_dev_sector (bdev, 0, &sect);
+        data = read_part_sector(state, 0, &sect);
         if (!data) {
                 ldm_crit ("Disk read failed.");
                 return false;
@@ -1391,8 +1391,8 @@ static bool ldm_frag_commit (struct list_head *frags, struct ldmdb *ldb)
 
 /**
  * ldm_get_vblks - Read the on-disk database of VBLKs into memory
- * @bdev:  Device holding the LDM Database
- * @base:  Offset, into @bdev, of the database
+ * @state: Partition check state including device holding the LDM Database
+ * @base:  Offset, into @state->bdev, of the database
  * @ldb:   Cache of the database structures
  *
  * To use the information from the VBLKs, they need to be read from the disk,
@@ -1401,8 +1401,8 @@ static bool ldm_frag_commit (struct list_head *frags, struct ldmdb *ldb)
  * Return:  'true'   All the VBLKs were read successfully
  *          'false'  An error occurred
  */
-static bool ldm_get_vblks (struct block_device *bdev, unsigned long base,
-                           struct ldmdb *ldb)
+static bool ldm_get_vblks(struct parsed_partitions *state, unsigned long base,
+                          struct ldmdb *ldb)
 {
         int size, perbuf, skip, finish, s, v, recs;
         u8 *data = NULL;
@@ -1410,7 +1410,7 @@ static bool ldm_get_vblks (struct block_device *bdev, unsigned long base,
         bool result = false;
         LIST_HEAD (frags);
 
-        BUG_ON (!bdev || !ldb);
+        BUG_ON(!state || !ldb);
 
         size   = ldb->vm.vblk_size;
         perbuf = 512 / size;
@@ -1418,7 +1418,7 @@ static bool ldm_get_vblks (struct block_device *bdev, unsigned long base,
         finish = (size * ldb->vm.last_vblk_seq) >> 9;
 
         for (s = skip; s < finish; s++) {               /* For each sector */
-                data = read_dev_sector (bdev, base + OFF_VMDB + s, &sect);
+                data = read_part_sector(state, base + OFF_VMDB + s, &sect);
                 if (!data) {
                         ldm_crit ("Disk read failed.");
                         goto out;
@@ -1474,8 +1474,7 @@ static void ldm_free_vblks (struct list_head *lh)
 
 /**
  * ldm_partition - Find out whether a device is a dynamic disk and handle it
- * @pp:    List of the partitions parsed so far
- * @bdev:  Device holding the LDM Database
+ * @state: Partition check state including device holding the LDM Database
  *
  * This determines whether the device @bdev is a dynamic disk and if so creates
  * the partitions necessary in the gendisk structure pointed to by @hd.
@@ -1485,21 +1484,21 @@ static void ldm_free_vblks (struct list_head *lh)
  * example, if the device is hda, we would have: hda1: LDM database, hda2, hda3,
  * and so on: the actual data containing partitions.
  *
- * Return:  1 Success, @bdev is a dynamic disk and we handled it
- *          0 Success, @bdev is not a dynamic disk
+ * Return:  1 Success, @state->bdev is a dynamic disk and we handled it
+ *          0 Success, @state->bdev is not a dynamic disk
  *         -1 An error occurred before enough information had been read
- *            Or @bdev is a dynamic disk, but it may be corrupted
+ *            Or @state->bdev is a dynamic disk, but it may be corrupted
  */
-int ldm_partition (struct parsed_partitions *pp, struct block_device *bdev)
+int ldm_partition(struct parsed_partitions *state)
 {
         struct ldmdb  *ldb;
         unsigned long base;
         int result = -1;
 
-        BUG_ON (!pp || !bdev);
+        BUG_ON(!state);
 
         /* Look for signs of a Dynamic Disk */
-        if (!ldm_validate_partition_table (bdev))
+        if (!ldm_validate_partition_table(state))
                 return 0;
 
         ldb = kmalloc (sizeof (*ldb), GFP_KERNEL);
@@ -1509,15 +1508,15 @@ int ldm_partition (struct parsed_partitions *pp, struct block_device *bdev)
         }
 
         /* Parse and check privheads. */
-        if (!ldm_validate_privheads (bdev, &ldb->ph))
+        if (!ldm_validate_privheads(state, &ldb->ph))
                 goto out;               /* Already logged */
 
         /* All further references are relative to base (database start). */
         base = ldb->ph.config_start;
 
         /* Parse and check tocs and vmdb. */
-        if (!ldm_validate_tocblocks (bdev, base, ldb) ||
-            !ldm_validate_vmdb      (bdev, base, ldb))
+        if (!ldm_validate_tocblocks(state, base, ldb) ||
+            !ldm_validate_vmdb(state, base, ldb))
                 goto out;               /* Already logged */
 
         /* Initialize vblk lists in ldmdb struct */
@@ -1527,13 +1526,13 @@ int ldm_partition (struct parsed_partitions *pp, struct block_device *bdev)
         INIT_LIST_HEAD (&ldb->v_comp);
         INIT_LIST_HEAD (&ldb->v_part);
 
-        if (!ldm_get_vblks (bdev, base, ldb)) {
+        if (!ldm_get_vblks(state, base, ldb)) {
                 ldm_crit ("Failed to read the VBLKs from the database.");
                 goto cleanup;
         }
 
         /* Finally, create the data partition devices. */
-        if (ldm_create_data_partitions (pp, ldb)) {
+        if (ldm_create_data_partitions(state, ldb)) {
                 ldm_debug ("Parsed LDM database successfully.");
                 result = 1;
         }