From: Dave Hansen Date: Fri, 15 Feb 2008 22:37:56 +0000 (-0800) Subject: [PATCH] r/o bind mounts: check mnt instead of superblock directly X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2c463e95480829a2fe8f386589516e13b1289db6;p=linux-beck.git [PATCH] r/o bind mounts: check mnt instead of superblock directly If we depend on the inodes for writeability, we will not catch the r/o mounts when implemented. This patches uses __mnt_want_write(). It does not guarantee that the mount will stay writeable after the check. But, this is OK for one of the checks because it is just for a printk(). The other two are probably unnecessary and duplicate existing checks in the VFS. This won't make them better checks than before, but it will make them detect r/o mounts. Acked-by: Al Viro Signed-off-by: Christoph Hellwig Signed-off-by: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Al Viro --- diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 6cea7479c5b4..d9e30ac2798d 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -967,7 +967,8 @@ static int is_atomic_open(struct inode *dir, struct nameidata *nd) if (nd->flags & LOOKUP_DIRECTORY) return 0; /* Are we trying to write to a read only partition? */ - if (IS_RDONLY(dir) && (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE))) + if (__mnt_is_readonly(nd->path.mnt) && + (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE))) return 0; return 1; } diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 626dfd38528f..304bf5f643c9 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1912,7 +1912,7 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, inode->i_mode, IS_IMMUTABLE(inode)? " immut" : "", IS_APPEND(inode)? " append" : "", - IS_RDONLY(inode)? " ro" : ""); + __mnt_is_readonly(exp->ex_path.mnt)? " ro" : ""); dprintk(" owner %d/%d user %d/%d\n", inode->i_uid, inode->i_gid, current->fsuid, current->fsgid); #endif @@ -1923,7 +1923,8 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, */ if (!(acc & MAY_LOCAL_ACCESS)) if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) { - if (exp_rdonly(rqstp, exp) || IS_RDONLY(inode)) + if (exp_rdonly(rqstp, exp) || + __mnt_is_readonly(exp->ex_path.mnt)) return nfserr_rofs; if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode)) return nfserr_perm;