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| author | Tejun Heo <tj@kernel.org> | 2010-11-13 11:55:17 +0100 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2010-11-13 11:55:17 +0100 |
| commit | 75f1dc0d076d1c1168f2115f1941ea627d38bd5a (patch) | |
| tree | af12858b842579e8924b30cb636b96fcca6f46b1 | |
| parent | 6a027eff62f6ae32d49f2ae5dadd6f4eee1ddae2 (diff) | |
| download | linux-stable-75f1dc0d076d1c1168f2115f1941ea627d38bd5a.tar.gz linux-stable-75f1dc0d076d1c1168f2115f1941ea627d38bd5a.tar.bz2 linux-stable-75f1dc0d076d1c1168f2115f1941ea627d38bd5a.zip | |
block: check bdev_read_only() from blkdev_get()
bdev read-only status can be queried using bdev_read_only() and may
change while the device is being opened. Enforce it by checking it
from blkdev_get() after open succeeds.
This makes bdev_read_only() check in open_bdev_exclusive() and
fsg_lun_open() unnecessary. Drop them.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: linux-usb@vger.kernel.org
| -rw-r--r-- | drivers/usb/gadget/storage_common.c | 7 | ||||
| -rw-r--r-- | fs/block_dev.c | 11 |
2 files changed, 8 insertions, 10 deletions
diff --git a/drivers/usb/gadget/storage_common.c b/drivers/usb/gadget/storage_common.c index 3b513bafaf2a..b015561fd602 100644 --- a/drivers/usb/gadget/storage_common.c +++ b/drivers/usb/gadget/storage_common.c @@ -543,7 +543,7 @@ static int fsg_lun_open(struct fsg_lun *curlun, const char *filename) ro = curlun->initially_ro; if (!ro) { filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0); - if (-EROFS == PTR_ERR(filp)) + if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES) ro = 1; } if (ro) @@ -558,10 +558,7 @@ static int fsg_lun_open(struct fsg_lun *curlun, const char *filename) if (filp->f_path.dentry) inode = filp->f_path.dentry->d_inode; - if (inode && S_ISBLK(inode->i_mode)) { - if (bdev_read_only(inode->i_bdev)) - ro = 1; - } else if (!inode || !S_ISREG(inode->i_mode)) { + if (!inode || (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) { LINFO(curlun, "invalid file type: %s\n", filename); goto out; } diff --git a/fs/block_dev.c b/fs/block_dev.c index 269bfbbd10fc..606a5259f87f 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1149,6 +1149,12 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) res = __blkdev_get(bdev, mode, 0); + /* __blkdev_get() may alter read only status, check it afterwards */ + if (!res && (mode & FMODE_WRITE) && bdev_read_only(bdev)) { + __blkdev_put(bdev, mode, 0); + res = -EACCES; + } + if (whole) { /* finish claiming */ spin_lock(&bdev_lock); @@ -1453,11 +1459,6 @@ struct block_device *open_bdev_exclusive(const char *path, fmode_t mode, void *h if (error) return ERR_PTR(error); - if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) { - blkdev_put(bdev, mode); - return ERR_PTR(-EACCES); - } - return bdev; } |