diff options
| author | Jiri Kosina <jkosina@suse.cz> | 2012-05-18 13:50:28 +0200 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2012-05-18 15:19:11 +0200 |
| commit | bfa10b8c98bb335bc3e401d3ec947d446f04d1aa (patch) | |
| tree | 70c1ace62544811e7f4f39f8bab8b85ee9f89017 /drivers/block | |
| parent | 070ad7e793dc6ff753ee682ef7790b3373b471f6 (diff) | |
| download | linux-bfa10b8c98bb335bc3e401d3ec947d446f04d1aa.tar.bz2 | |
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')
| -rw-r--r-- | drivers/block/floppy.c | 18 |
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: |