Messages in this thread Patch in this message | | | Date | Wed, 30 Nov 2011 22:23:12 -0500 | From | Phillip Susi <> | Subject | [PATCH 1/2] Add partition resize function to BLKPG ioctl |
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Add a new operation code ( BLKPG_RES_PARTITION ) to the BLKPG ioctl that allows altering the size of an existing partition, even if it is currently in use.
Signed-off-by: Phillip Susi <psusi@cfl.rr.com> - --- block/ioctl.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++- include/linux/blkpg.h | 1 + 2 files changed, 50 insertions(+), 2 deletions(-)
diff --git a/block/ioctl.c b/block/ioctl.c index ca939fc..f97e6a4 100644 - --- a/block/ioctl.c +++ b/block/ioctl.c @@ -36,8 +36,8 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user case BLKPG_ADD_PARTITION: start = p.start >> 9; length = p.length >> 9; - - /* check for fit in a hd_struct */ - - if (sizeof(sector_t) == sizeof(long) && + /* check for fit in a hd_struct */ + if (sizeof(sector_t) == sizeof(long) && sizeof(long long) > sizeof(long)) { long pstart = start, plength = length; if (pstart != start || plength != length @@ -92,6 +92,53 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user bdput(bdevp); return 0; + case BLKPG_RES_PARTITION: + start = p.start >> 9; + length = p.length >> 9; + /* check for fit in a hd_struct */ + if (sizeof(sector_t) == sizeof(long) && + sizeof(long long) > sizeof(long)) { + long pstart = start, plength = length; + if (pstart != start || plength != length + || pstart < 0 || plength < 0) + return -EINVAL; + } + + mutex_lock(&bdev->bd_mutex); + + /* overlap? */ + disk_part_iter_init(&piter, disk, + DISK_PITER_INCL_EMPTY); + while ((part = disk_part_iter_next(&piter))) { + if (part->partno != partno && !(start + length <= part->start_sect || + start >= part->start_sect + part->nr_sects)) { + disk_part_iter_exit(&piter); + mutex_unlock(&bdev->bd_mutex); + return -EBUSY; + } + } + disk_part_iter_exit(&piter); + part = disk_get_part(disk, partno); + if (!part) + { + mutex_unlock(&bdev->bd_mutex); + return -ENXIO; + } + if (start != part->start_sect) + { + mutex_unlock(&bdev->bd_mutex); + disk_put_part(part); + return -EINVAL; + } + part->nr_sects = length; + bdevp = bdget(part_devt(part)); + mutex_lock(&bdevp->bd_mutex); + i_size_write(bdevp->bd_inode, p.length); + mutex_unlock(&bdevp->bd_mutex); + bdput(bdevp); + disk_put_part(part); + mutex_unlock(&bdev->bd_mutex); + return 0; default: return -EINVAL; } diff --git a/include/linux/blkpg.h b/include/linux/blkpg.h index faf8a45..103da38 100644 - --- a/include/linux/blkpg.h +++ b/include/linux/blkpg.h @@ -40,6 +40,7 @@ struct blkpg_ioctl_arg { /* The subfunctions (for the op field) */ #define BLKPG_ADD_PARTITION 1 #define BLKPG_DEL_PARTITION 2 +#define BLKPG_RES_PARTITION 3 /* Sizes of name fields. Unused at present. */ #define BLKPG_DEVNAMELTH 64 - -- 1.7.5.4 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk7W8yAACgkQJ4UciIs+XuKpiwCfd8YC2241ScOcruAoGvBnTyVZ p6UAoI5JT/UX4gkilpjmTKbuBLzeCTv4 =K/d3 -----END PGP SIGNATURE-----
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