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authorJiri Kosina <jkosina@suse.cz>2012-05-18 15:50:28 +0400
committerJiri Kosina <jkosina@suse.cz>2012-05-18 17:19:11 +0400
commitbfa10b8c98bb335bc3e401d3ec947d446f04d1aa (patch)
tree70c1ace62544811e7f4f39f8bab8b85ee9f89017 /drivers/block/floppy.c
parent070ad7e793dc6ff753ee682ef7790b3373b471f6 (diff)
downloadlinux-bfa10b8c98bb335bc3e401d3ec947d446f04d1aa.tar.xz
floppy: remove floppy-specific O_EXCL handling
Block layer now handles O_EXCL in a generic way for block devices. The semantics is however different for floppy and all other block devices, as floppy driver contains its own O_EXCL handling. The semantics for all-but-floppy bdevs is "there can be at most one O_EXCL open of this file", while for floppy bdev the semantics is "if someone has the bdev open with O_EXCL, noone else can open it". There is actual userspace-observable change in behavior because of this since commit e525fd89d380c ("block: make blkdev_get/put() handle exclusive access") -- on kernels containing this commit, mount of /dev/fd0 causes the fd0 block device be claimed with _EXCL, preventing subsequent open(/dev/fd0). Bring things back into shape, i.e. make it possible, analogically to other block devices, to mount the floppy and open() it afterwards -- remove the floppy-specific handling and let the generic bdev code O_EXCL handling take over. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: NeilBrown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/block/floppy.c')
-rw-r--r--drivers/block/floppy.c18
1 files changed, 4 insertions, 14 deletions
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 48e1d70740dc..cce7df367b79 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3607,9 +3607,7 @@ static int floppy_release(struct gendisk *disk, fmode_t mode)
mutex_lock(&floppy_mutex);
mutex_lock(&open_lock);
- if (UDRS->fd_ref < 0)
- UDRS->fd_ref = 0;
- else if (!UDRS->fd_ref--) {
+ if (!UDRS->fd_ref--) {
DPRINT("floppy_release with fd_ref == 0");
UDRS->fd_ref = 0;
}
@@ -3645,13 +3643,7 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
set_bit(FD_VERIFY_BIT, &UDRS->flags);
}
- if (UDRS->fd_ref == -1 || (UDRS->fd_ref && (mode & FMODE_EXCL)))
- goto out2;
-
- if (mode & FMODE_EXCL)
- UDRS->fd_ref = -1;
- else
- UDRS->fd_ref++;
+ UDRS->fd_ref++;
opened_bdev[drive] = bdev;
@@ -3714,10 +3706,8 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
mutex_unlock(&floppy_mutex);
return 0;
out:
- if (UDRS->fd_ref < 0)
- UDRS->fd_ref = 0;
- else
- UDRS->fd_ref--;
+ UDRS->fd_ref--;
+
if (!UDRS->fd_ref)
opened_bdev[drive] = NULL;
out2: