swap: Add flag to identify block swap devices

Added SWP_BLKDEV flag to distinguish block and regular file backed
swap devices. We could also check if a swap is entire block device,
rather than a file, by:
S_ISBLK(swap_info_struct->swap_file->f_mapping->host->i_mode)
but, I think, simply checking this flag is more convenient.

Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Nigel Cunningham <nigel@tuxonice.net>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Nitin Gupta 2010-05-17 11:02:42 +05:30 committed by Greg Kroah-Hartman
parent f4a68b9388
commit b272564395
2 changed files with 2 additions and 0 deletions

View File

@ -146,6 +146,7 @@ enum {
SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */
SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */
SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */
SWP_BLKDEV = (1 << 6), /* its a block device */
/* add others here before... */
SWP_SCANNING = (1 << 8), /* refcount in scan_swap_map */
};

View File

@ -1884,6 +1884,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
if (error < 0)
goto bad_swap;
p->bdev = bdev;
p->flags |= SWP_BLKDEV;
} else if (S_ISREG(inode->i_mode)) {
p->bdev = inode->i_sb->s_bdev;
mutex_lock(&inode->i_mutex);