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@xxxxxxxxxx>
Cc: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
---
drivers/usb/gadget/storage_common.c | 7 ++-----
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 3b513ba..b015561 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 269bfbb..606a525 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;
}
--
1.7.1
--
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