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| author |   Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> | 2005-05-01 08:58:57 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-05-01 08:58:57 -0700 |
| commit | 2c49be99ede1e3685a9817a564b4b1678d48e1b9 (patch) | |
| tree | d5e0b59f25351e4bfd80fc656e8f872c83c5f885 /arch/um | |
| parent | [PATCH] uml: commentary about forking flag (diff) | |
| download | linux-dev-2c49be99ede1e3685a9817a564b4b1678d48e1b9.tar.xz linux-dev-2c49be99ede1e3685a9817a564b4b1678d48e1b9.zip | |
[PATCH] uml ubd: handle readonly status
Use the set_disk_ro() API when the backing file is read-only, to mark the disk
read-only, during the ->open(). The current hack does not work when doing a
mount -o remount.
Also, mark explicitly the code paths which should no more be triggerable (I've
removed the WARN_ON(1) things). They should actually become BUG()s probably
but I'll avoid that since I'm not so sure the change works so well. I gave it
only some limited testing.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
CC: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/um')
| -rw-r--r-- | arch/um/drivers/ubd_kern.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 4d8b165bfa48..9a56ff94308d 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -156,6 +156,7 @@ static struct gendisk *fake_gendisk[MAX_DEV]; static struct openflags global_openflags = OPEN_FLAGS; struct cow { + /* This is the backing file, actually */ char *file; int fd; unsigned long *bitmap; @@ -927,10 +928,14 @@ static int ubd_open(struct inode *inode, struct file *filp) } } dev->count++; - if((filp->f_mode & FMODE_WRITE) && !dev->openflags.w){ + set_disk_ro(disk, !dev->openflags.w); + + /* This should no more be needed. And it didn't work anyway to exclude + * read-write remounting of filesystems.*/ + /*if((filp->f_mode & FMODE_WRITE) && !dev->openflags.w){ if(--dev->count == 0) ubd_close(dev); err = -EROFS; - } + }*/ out: return(err); } @@ -1096,6 +1101,7 @@ static int prepare_request(struct request *req, struct io_thread_req *io_req) if(req->rq_status == RQ_INACTIVE) return(1); + /* This should be impossible now */ if((rq_data_dir(req) == WRITE) && !dev->openflags.w){ printk("Write attempted on readonly ubd device %s\n", disk->disk_name); @@ -1243,6 +1249,7 @@ static int ubd_check_remapped(int fd, unsigned long address, int is_write, /* It's a write to a ubd device */ + /* This should be impossible now */ if(!dev->openflags.w){ /* It's a write access on a read-only device - probably * shouldn't happen. If the kernel is trying to change @@ -1605,8 +1612,7 @@ void do_io(struct io_thread_req *req) } } while((n < len) && (n != 0)); if (n < len) memset(&buf[n], 0, len - n); - } - else { + } else { n = os_write_file(req->fds[bit], buf, len); if(n != len){ printk("do_io - write failed err = %d " |