On Fri, 2011-07-29 at 14:50 +0100, Sachin Prabhu wrote: > When you normally attempt to mount a share twice on the same mountpoint, > a check in do_add_mount causes it to return an error > > # mount localhost:/nfsv3 /mnt > # mount localhost:/nfsv3 /mnt > mount.nfs: /mnt is already mounted or busy > > However when using the option 'noac', the user is able to mount the same > share on the same mountpoint multiple times. This happens because a > share mounted with the noac option is automatically assigned the 'sync' > flag MS_SYNCHRONOUS in nfs_initialise_sb(). This flag is set after the > check for already existing superblocks is done in sget(). The check for > the mount flags in nfs_compare_mount_options() does not take into > account the 'sync' flag applied later on in the code path. This means > that when using 'noac', a new superblock structure is assigned for every > new mount of the same share and multiple shares on the same mountpoint > are allowed. > > ie. > # mount -onoac localhost:/nfsv3 /mnt > can be run multiple times. > > The patch checks for noac and assigns the sync flag before sget() is > called to obtain an already existing superblock structure. > > > Signed-off-by: Sachin Prabhu <sprabhu@xxxxxxxxxx> Hi Sachin, This patch fails to apply with the error 'corrupt patch at line 6'. It looks to me as if your mailer has reformatted it for you. Cheers Trond -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@xxxxxxxxxx www.netapp.com -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
