block, partition: add partition_meta_info to hd_struct

I'm reposting this patch series as v4 since there have been no additional
comments, and I cleaned up one extra bit of unneeded code (in 3/3). The patches
are against Linus's tree: 2bfc96a127bc1cc94d26bfaa40159966064f9c8c
(2.6.36-rc3).

Would this patchset be suitable for inclusion in an mm branch?

This changes adds a partition_meta_info struct which itself contains a
union of structures that provide partition table specific metadata.

This change leaves the union empty. The subsequent patch includes an
implementation for CONFIG_EFI_PARTITION-based metadata.

Signed-off-by: Will Drewry <wad@chromium.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

2 files changed, 23 insertions, 3 deletions

diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 79fbf3f390f0..6dfbee03ccc6 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -352,6 +352,7 @@ static void part_release(struct device *dev)
 {
         struct hd_struct *p = dev_to_part(dev);
         free_part_stats(p);
+        free_part_info(p);
         kfree(p);
 }
 
@@ -401,7 +402,8 @@ static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
                    whole_disk_show, NULL);
 
 struct hd_struct *add_partition(struct gendisk *disk, int partno,
-                                sector_t start, sector_t len, int flags)
+                                sector_t start, sector_t len, int flags,
+                                struct partition_meta_info *info)
 {
         struct hd_struct *p;
         dev_t devt = MKDEV(0, 0);
@@ -438,6 +440,14 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno,
         p->partno = partno;
         p->policy = get_disk_ro(disk);
 
+        if (info) {
+                struct partition_meta_info *pinfo = alloc_part_info(disk);
+                if (!pinfo)
+                        goto out_free_stats;
+                memcpy(pinfo, info, sizeof(*info));
+                p->info = pinfo;
+        }
+
         dname = dev_name(ddev);
         if (isdigit(dname[strlen(dname) - 1]))
                 dev_set_name(pdev, "%sp%d", dname, partno);
@@ -451,7 +461,7 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno,
 
         err = blk_alloc_devt(p, &devt);
         if (err)
-                goto out_free_stats;
+                goto out_free_info;
         pdev->devt = devt;
 
         /* delay uevent until 'holders' subdir is created */
@@ -481,6 +491,8 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno,
 
         return p;
 
+out_free_info:
+        free_part_info(p);
 out_free_stats:
         free_part_stats(p);
 out_free:
@@ -642,6 +654,7 @@ rescan:
         /* add partitions */
         for (p = 1; p < state->limit; p++) {
                 sector_t size, from;
+                struct partition_meta_info *info = NULL;
 
                 size = state->parts[p].size;
                 if (!size)
@@ -675,8 +688,12 @@ rescan:
                                 size = get_capacity(disk) - from;
                         }
                 }
+
+                if (state->parts[p].has_info)
+                        info = &state->parts[p].info;
                 part = add_partition(disk, p, from, size,
-                                     state->parts[p].flags);
+                                     state->parts[p].flags,
+                                     &state->parts[p].info);
                 if (IS_ERR(part)) {
                         printk(KERN_ERR " %s: p%d could not be added: %ld\n",
                                disk->disk_name, p, -PTR_ERR(part));
diff --git a/fs/partitions/check.h b/fs/partitions/check.h
index 8e4e103ba216..d68bf4dc3bc2 100644
--- a/fs/partitions/check.h
+++ b/fs/partitions/check.h
@@ -1,5 +1,6 @@
 #include <linux/pagemap.h>
 #include <linux/blkdev.h>
+#include <linux/genhd.h>
 
 /*
  * add_gd_partition adds a partitions details to the devices partition
@@ -12,6 +13,8 @@ struct parsed_partitions {
                 sector_t from;
                 sector_t size;
                 int flags;
+                bool has_info;
+                struct partition_meta_info info;
         } parts[DISK_MAX_PARTS];
         int next;
         int limit;