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, 37 insertions, 48 deletions

diff --git a/fs/partitions/msdos.c b/fs/partitions/msdos.c
index 90be97f..645a68d 100644
--- a/fs/partitions/msdos.c
+++ b/fs/partitions/msdos.c
@@ -64,7 +64,7 @@ msdos_magic_present(unsigned char *p)
 #define AIX_LABEL_MAGIC2	0xC2
 #define AIX_LABEL_MAGIC3	0xD4
 #define AIX_LABEL_MAGIC4	0xC1
-static int aix_magic_present(unsigned char *p, struct block_device *bdev)
+static int aix_magic_present(struct parsed_partitions *state, unsigned char *p)
 {
 	struct partition *pt = (struct partition *) (p + 0x1be);
 	Sector sect;
@@ -85,7 +85,7 @@ static int aix_magic_present(unsigned char *p, struct block_device *bdev)
 			is_extended_partition(pt))
 			return 0;
 	}
-	d = read_dev_sector(bdev, 7, &sect);
+	d = read_part_sector(state, 7, &sect);
 	if (d) {
 		if (d[0] == '_' && d[1] == 'L' && d[2] == 'V' && d[3] == 'M')
 			ret = 1;
@@ -105,15 +105,14 @@ static int aix_magic_present(unsigned char *p, struct block_device *bdev)
  * only for the actual data partitions.
  */
 
-static void
-parse_extended(struct parsed_partitions *state, struct block_device *bdev,
-			sector_t first_sector, sector_t first_size)
+static void parse_extended(struct parsed_partitions *state,
+			   sector_t first_sector, sector_t first_size)
 {
 	struct partition *p;
 	Sector sect;
 	unsigned char *data;
 	sector_t this_sector, this_size;
-	sector_t sector_size = bdev_logical_block_size(bdev) / 512;
+	sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
 	int loopct = 0;		/* number of links followed
 				   without finding a data partition */
 	int i;
@@ -126,7 +125,7 @@ parse_extended(struct parsed_partitions *state, struct block_device *bdev,
 			return;
 		if (state->next == state->limit)
 			return;
-		data = read_dev_sector(bdev, this_sector, &sect);
+		data = read_part_sector(state, this_sector, &sect);
 		if (!data)
 			return;
 
@@ -198,9 +197,8 @@ done:
 /* james@bpgc.com: Solaris has a nasty indicator: 0x82 which also
    indicates linux swap.  Be careful before believing this is Solaris. */
 
-static void
-parse_solaris_x86(struct parsed_partitions *state, struct block_device *bdev,
-			sector_t offset, sector_t size, int origin)
+static void parse_solaris_x86(struct parsed_partitions *state,
+			      sector_t offset, sector_t size, int origin)
 {
 #ifdef CONFIG_SOLARIS_X86_PARTITION
 	Sector sect;
@@ -208,7 +206,7 @@ parse_solaris_x86(struct parsed_partitions *state, struct block_device *bdev,
 	int i;
 	short max_nparts;
 
-	v = (struct solaris_x86_vtoc *)read_dev_sector(bdev, offset+1, &sect);
+	v = read_part_sector(state, offset + 1, &sect);
 	if (!v)
 		return;
 	if (le32_to_cpu(v->v_sanity) != SOLARIS_X86_VTOC_SANE) {
@@ -245,16 +243,15 @@ parse_solaris_x86(struct parsed_partitions *state, struct block_device *bdev,
  * Create devices for BSD partitions listed in a disklabel, under a
  * dos-like partition. See parse_extended() for more information.
  */
-static void
-parse_bsd(struct parsed_partitions *state, struct block_device *bdev,
-		sector_t offset, sector_t size, int origin, char *flavour,
-		int max_partitions)
+static void parse_bsd(struct parsed_partitions *state,
+		      sector_t offset, sector_t size, int origin, char *flavour,
+		      int max_partitions)
 {
 	Sector sect;
 	struct bsd_disklabel *l;
 	struct bsd_partition *p;
 
-	l = (struct bsd_disklabel *)read_dev_sector(bdev, offset+1, &sect);
+	l = read_part_sector(state, offset + 1, &sect);
 	if (!l)
 		return;
 	if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) {
@@ -291,33 +288,28 @@ parse_bsd(struct parsed_partitions *state, struct block_device *bdev,
 }
 #endif
 
-static void
-parse_freebsd(struct parsed_partitions *state, struct block_device *bdev,
-		sector_t offset, sector_t size, int origin)
+static void parse_freebsd(struct parsed_partitions *state,
+			  sector_t offset, sector_t size, int origin)
 {
 #ifdef CONFIG_BSD_DISKLABEL
-	parse_bsd(state, bdev, offset, size, origin,
-			"bsd", BSD_MAXPARTITIONS);
+	parse_bsd(state, offset, size, origin, "bsd", BSD_MAXPARTITIONS);
 #endif
 }
 
-static void
-parse_netbsd(struct parsed_partitions *state, struct block_device *bdev,
-		sector_t offset, sector_t size, int origin)
+static void parse_netbsd(struct parsed_partitions *state,
+			 sector_t offset, sector_t size, int origin)
 {
 #ifdef CONFIG_BSD_DISKLABEL
-	parse_bsd(state, bdev, offset, size, origin,
-			"netbsd", BSD_MAXPARTITIONS);
+	parse_bsd(state, offset, size, origin, "netbsd", BSD_MAXPARTITIONS);
 #endif
 }
 
-static void
-parse_openbsd(struct parsed_partitions *state, struct block_device *bdev,
-		sector_t offset, sector_t size, int origin)
+static void parse_openbsd(struct parsed_partitions *state,
+			  sector_t offset, sector_t size, int origin)
 {
 #ifdef CONFIG_BSD_DISKLABEL
-	parse_bsd(state, bdev, offset, size, origin,
-			"openbsd", OPENBSD_MAXPARTITIONS);
+	parse_bsd(state, offset, size, origin, "openbsd",
+		  OPENBSD_MAXPARTITIONS);
 #endif
 }
 
@@ -325,16 +317,15 @@ parse_openbsd(struct parsed_partitions *state, struct block_device *bdev,
  * Create devices for Unixware partitions listed in a disklabel, under a
  * dos-like partition. See parse_extended() for more information.
  */
-static void
-parse_unixware(struct parsed_partitions *state, struct block_device *bdev,
-		sector_t offset, sector_t size, int origin)
+static void parse_unixware(struct parsed_partitions *state,
+			   sector_t offset, sector_t size, int origin)
 {
 #ifdef CONFIG_UNIXWARE_DISKLABEL
 	Sector sect;
 	struct unixware_disklabel *l;
 	struct unixware_slice *p;
 
-	l = (struct unixware_disklabel *)read_dev_sector(bdev, offset+29, &sect);
+	l = read_part_sector(state, offset + 29, &sect);
 	if (!l)
 		return;
 	if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC ||
@@ -365,9 +356,8 @@ parse_unixware(struct parsed_partitions *state, struct block_device *bdev,
  * Anand Krishnamurthy <anandk@wiproge.med.ge.com>
  * Rajeev V. Pillai    <rajeevvp@yahoo.com>
  */
-static void
-parse_minix(struct parsed_partitions *state, struct block_device *bdev,
-		sector_t offset, sector_t size, int origin)
+static void parse_minix(struct parsed_partitions *state,
+			sector_t offset, sector_t size, int origin)
 {
 #ifdef CONFIG_MINIX_SUBPARTITION
 	Sector sect;
@@ -375,7 +365,7 @@ parse_minix(struct parsed_partitions *state, struct block_device *bdev,
 	struct partition *p;
 	int i;
 
-	data = read_dev_sector(bdev, offset, &sect);
+	data = read_part_sector(state, offset, &sect);
 	if (!data)
 		return;
 
@@ -404,8 +394,7 @@ parse_minix(struct parsed_partitions *state, struct block_device *bdev,
 
 static struct {
 	unsigned char id;
-	void (*parse)(struct parsed_partitions *, struct block_device *,
-			sector_t, sector_t, int);
+	void (*parse)(struct parsed_partitions *, sector_t, sector_t, int);
 } subtypes[] = {
 	{FREEBSD_PARTITION, parse_freebsd},
 	{NETBSD_PARTITION, parse_netbsd},
@@ -417,16 +406,16 @@ static struct {
 	{0, NULL},
 };
  
-int msdos_partition(struct parsed_partitions *state, struct block_device *bdev)
+int msdos_partition(struct parsed_partitions *state)
 {
-	sector_t sector_size = bdev_logical_block_size(bdev) / 512;
+	sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
 	Sector sect;
 	unsigned char *data;
 	struct partition *p;
 	struct fat_boot_sector *fb;
 	int slot;
 
-	data = read_dev_sector(bdev, 0, &sect);
+	data = read_part_sector(state, 0, &sect);
 	if (!data)
 		return -1;
 	if (!msdos_magic_present(data + 510)) {
@@ -434,7 +423,7 @@ int msdos_partition(struct parsed_partitions *state, struct block_device *bdev)
 		return 0;
 	}
 
-	if (aix_magic_present(data, bdev)) {
+	if (aix_magic_present(state, data)) {
 		put_dev_sector(sect);
 		printk( " [AIX]");
 		return 0;
@@ -503,7 +492,7 @@ int msdos_partition(struct parsed_partitions *state, struct block_device *bdev)
 			put_partition(state, slot, start, n);
 
 			printk(" <");
-			parse_extended(state, bdev, start, size);
+			parse_extended(state, start, size);
 			printk(" >");
 			continue;
 		}
@@ -532,8 +521,8 @@ int msdos_partition(struct parsed_partitions *state, struct block_device *bdev)
 
 		if (!subtypes[n].parse)
 			continue;
-		subtypes[n].parse(state, bdev, start_sect(p)*sector_size,
-						nr_sects(p)*sector_size, slot);
+		subtypes[n].parse(state, start_sect(p) * sector_size,
+				  nr_sects(p) * sector_size, slot);
 	}
 	put_dev_sector(sect);
 	return 1;