block: add secure discard
Adrian Hunter [Wed, 11 Aug 2010 21:17:49 +0000 (14:17 -0700)]
Secure discard is the same as discard except that all copies of the
discarded sectors (perhaps created by garbage collection) must also be
erased.

Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Madhusudhan Chikkature <madhu.cr@ti.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ben Gardiner <bengardiner@nanometrics.ca>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

block/blk-core.c
block/blk-lib.c
block/compat_ioctl.c
block/elevator.c
block/ioctl.c
include/linux/blk_types.h
include/linux/blkdev.h
include/linux/fs.h
kernel/trace/blktrace.c

index 7da630e..ee1a1e7 100644 (file)
@@ -1514,7 +1514,10 @@ static inline void __generic_make_request(struct bio *bio)
                if (bio_check_eod(bio, nr_sectors))
                        goto end_io;
 
-               if ((bio->bi_rw & REQ_DISCARD) && !blk_queue_discard(q)) {
+               if ((bio->bi_rw & REQ_DISCARD) &&
+                   (!blk_queue_discard(q) ||
+                    ((bio->bi_rw & REQ_SECURE) &&
+                     !blk_queue_secdiscard(q)))) {
                        err = -EOPNOTSUPP;
                        goto end_io;
                }
index c1fc55a..c392029 100644 (file)
@@ -62,6 +62,12 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
                max_discard_sectors &= ~(disc_sects - 1);
        }
 
+       if (flags & BLKDEV_IFL_SECURE) {
+               if (!blk_queue_secdiscard(q))
+                       return -EOPNOTSUPP;
+               type |= DISCARD_SECURE;
+       }
+
        while (nr_sects && !ret) {
                bio = bio_alloc(gfp_mask, 1);
                if (!bio) {
index d530856..119f07b 100644 (file)
@@ -703,6 +703,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
        case BLKFLSBUF:
        case BLKROSET:
        case BLKDISCARD:
+       case BLKSECDISCARD:
        /*
         * the ones below are implemented in blkdev_locked_ioctl,
         * but we call blkdev_ioctl, which gets the lock for us
index 816a7c8..ec585c9 100644 (file)
@@ -83,6 +83,12 @@ int elv_rq_merge_ok(struct request *rq, struct bio *bio)
                return 0;
 
        /*
+        * Don't merge discard requests and secure discard requests
+        */
+       if ((bio->bi_rw & REQ_SECURE) != (rq->bio->bi_rw & REQ_SECURE))
+               return 0;
+
+       /*
         * different data direction or already started, don't merge
         */
        if (bio_data_dir(bio) != rq_data_dir(rq))
index 09fd7f1..d8052f0 100644 (file)
@@ -114,8 +114,10 @@ static int blkdev_reread_part(struct block_device *bdev)
 }
 
 static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
-                            uint64_t len)
+                            uint64_t len, int secure)
 {
+       unsigned long flags = BLKDEV_IFL_WAIT;
+
        if (start & 511)
                return -EINVAL;
        if (len & 511)
@@ -125,8 +127,9 @@ static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
 
        if (start + len > (bdev->bd_inode->i_size >> 9))
                return -EINVAL;
-       return blkdev_issue_discard(bdev, start, len, GFP_KERNEL,
-                                   BLKDEV_IFL_WAIT);
+       if (secure)
+               flags |= BLKDEV_IFL_SECURE;
+       return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
 }
 
 static int put_ushort(unsigned long arg, unsigned short val)
@@ -213,7 +216,8 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
                set_device_ro(bdev, n);
                return 0;
 
-       case BLKDISCARD: {
+       case BLKDISCARD:
+       case BLKSECDISCARD: {
                uint64_t range[2];
 
                if (!(mode & FMODE_WRITE))
@@ -222,7 +226,8 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
                if (copy_from_user(range, (void __user *)arg, sizeof(range)))
                        return -EFAULT;
 
-               return blk_ioctl_discard(bdev, range[0], range[1]);
+               return blk_ioctl_discard(bdev, range[0], range[1],
+                                        cmd == BLKSECDISCARD);
        }
 
        case HDIO_GETGEO: {
index 5369177..ca83a97 100644 (file)
@@ -150,6 +150,7 @@ enum rq_flag_bits {
        __REQ_FLUSH,            /* request for cache flush */
        __REQ_IO_STAT,          /* account I/O stat */
        __REQ_MIXED_MERGE,      /* merge of different types, fail separately */
+       __REQ_SECURE,           /* secure discard (used with __REQ_DISCARD) */
        __REQ_NR_BITS,          /* stops here */
 };
 
@@ -190,5 +191,6 @@ enum rq_flag_bits {
 #define REQ_FLUSH              (1 << __REQ_FLUSH)
 #define REQ_IO_STAT            (1 << __REQ_IO_STAT)
 #define REQ_MIXED_MERGE                (1 << __REQ_MIXED_MERGE)
+#define REQ_SECURE             (1 << __REQ_SECURE)
 
 #endif /* __LINUX_BLK_TYPES_H */
index 89c855c..2c54906 100644 (file)
@@ -389,6 +389,7 @@ struct request_queue
 #define QUEUE_FLAG_DISCARD     16      /* supports DISCARD */
 #define QUEUE_FLAG_NOXMERGES   17      /* No extended merges */
 #define QUEUE_FLAG_ADD_RANDOM  18      /* Contributes to random pool */
+#define QUEUE_FLAG_SECDISCARD  19      /* supports SECDISCARD */
 
 #define QUEUE_FLAG_DEFAULT     ((1 << QUEUE_FLAG_IO_STAT) |            \
                                 (1 << QUEUE_FLAG_CLUSTER) |            \
@@ -524,6 +525,8 @@ enum {
 #define blk_queue_stackable(q) \
        test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
 #define blk_queue_discard(q)   test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
+#define blk_queue_secdiscard(q)        (blk_queue_discard(q) && \
+       test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
 
 #define blk_noretry_request(rq) \
        ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
@@ -918,10 +921,12 @@ static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
 }
 enum{
        BLKDEV_WAIT,    /* wait for completion */
-       BLKDEV_BARRIER, /*issue request with barrier */
+       BLKDEV_BARRIER, /* issue request with barrier */
+       BLKDEV_SECURE,  /* secure discard */
 };
 #define BLKDEV_IFL_WAIT                (1 << BLKDEV_WAIT)
 #define BLKDEV_IFL_BARRIER     (1 << BLKDEV_BARRIER)
+#define BLKDEV_IFL_SECURE      (1 << BLKDEV_SECURE)
 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *,
                        unsigned long);
 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
index 267d026..7a0625e 100644 (file)
@@ -174,6 +174,7 @@ struct inodes_stat_t {
  */
 #define DISCARD_NOBARRIER      (WRITE | REQ_DISCARD)
 #define DISCARD_BARRIER                (WRITE | REQ_DISCARD | REQ_HARDBARRIER)
+#define DISCARD_SECURE         (DISCARD_NOBARRIER | REQ_SECURE)
 
 #define SEL_IN         1
 #define SEL_OUT                2
@@ -317,6 +318,7 @@ struct inodes_stat_t {
 #define BLKALIGNOFF _IO(0x12,122)
 #define BLKPBSZGET _IO(0x12,123)
 #define BLKDISCARDZEROES _IO(0x12,124)
+#define BLKSECDISCARD _IO(0x12,125)
 
 #define BMAP_IOCTL 1           /* obsolete - kept for compatibility */
 #define FIBMAP    _IO(0x00,1)  /* bmap access */
index 82499a5..959f8d6 100644 (file)
@@ -710,6 +710,9 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
        if (rq->cmd_flags & REQ_DISCARD)
                rw |= REQ_DISCARD;
 
+       if (rq->cmd_flags & REQ_SECURE)
+               rw |= REQ_SECURE;
+
        if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
                what |= BLK_TC_ACT(BLK_TC_PC);
                __blk_add_trace(bt, 0, blk_rq_bytes(rq), rw,
@@ -1816,6 +1819,8 @@ void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
                rwbs[i++] = 'S';
        if (rw & REQ_META)
                rwbs[i++] = 'M';
+       if (rw & REQ_SECURE)
+               rwbs[i++] = 'E';
 
        rwbs[i] = '\0';
 }
@@ -1828,6 +1833,9 @@ void blk_fill_rwbs_rq(char *rwbs, struct request *rq)
        if (rq->cmd_flags & REQ_DISCARD)
                rw |= REQ_DISCARD;
 
+       if (rq->cmd_flags & REQ_SECURE)
+               rw |= REQ_SECURE;
+
        bytes = blk_rq_bytes(rq);
 
        blk_fill_rwbs(rwbs, rw, bytes);