[patch 21/22] sys_mknodat(): elevate write count for vfs_mknod/create()
From: Dave Hansen <hansendc@us.ibm.com> This takes care of all of the direct callers of vfs_mknod(). Since a few of these cases also handle normal file creation as well, this also covers some calls to vfs_create(). Signed-off-by: Dave Hansen <hansendc@us.ibm.com> --- fs/namei.c | 12 ++++++++++++ fs/nfsd/vfs.c | 8 ++++++-- net/unix/af_unix.c | 4 ++++ 3 files changed, 22 insertions(+), 2 deletions(-) Index: 2.6.22-rc4-mm2-robindmount/fs/namei.c =================================================================== --- 2.6.22-rc4-mm2-robindmount.orig/fs/namei.c +++ 2.6.22-rc4-mm2-robindmount/fs/namei.c @@ -1949,14 +1949,26 @@ asmlinkage long sys_mknodat(int dfd, con if (!IS_ERR(dentry)) { switch (mode & S_IFMT) { case 0: case S_IFREG: + error = mnt_want_write(nd.mnt); + if (error) + break; error = vfs_create(nd.dentry->d_inode,dentry,mode,&nd); + mnt_drop_write(nd.mnt); break; case S_IFCHR: case S_IFBLK: + error = mnt_want_write(nd.mnt); + if (error) + break; error = vfs_mknod(nd.dentry->d_inode,dentry,mode, new_decode_dev(dev)); + mnt_drop_write(nd.mnt); break; case S_IFIFO: case S_IFSOCK: + error = mnt_want_write(nd.mnt); + if (error) + break; error = vfs_mknod(nd.dentry->d_inode,dentry,mode,0); + mnt_drop_write(nd.mnt); break; case S_IFDIR: error = -EPERM; Index: 2.6.22-rc4-mm2-robindmount/fs/nfsd/vfs.c =================================================================== --- 2.6.22-rc4-mm2-robindmount.orig/fs/nfsd/vfs.c +++ 2.6.22-rc4-mm2-robindmount/fs/nfsd/vfs.c @@ -1192,7 +1192,11 @@ nfsd_create(struct svc_rqst *rqstp, stru case S_IFBLK: case S_IFIFO: case S_IFSOCK: + host_err = mnt_want_write(fhp->fh_export->ex_mnt); + if (host_err) + break; host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); + mnt_drop_write(fhp->fh_export->ex_mnt); break; default: printk("nfsd: bad file type %o in nfsd_create\n", type); @@ -1811,7 +1815,7 @@ nfsd_permission(struct svc_export *exp, inode->i_mode, IS_IMMUTABLE(inode)? " immut" : "", IS_APPEND(inode)? " append" : "", - __mnt_is_readonly(exp->mnt)? " ro" : ""); + __mnt_is_readonly(exp->ex_mnt)? " ro" : ""); dprintk(" owner %d/%d user %d/%d\n", inode->i_uid, inode->i_gid, current->fsuid, current->fsgid); #endif @@ -1822,7 +1826,7 @@ nfsd_permission(struct svc_export *exp, */ if (!(acc & MAY_LOCAL_ACCESS)) if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) { - if (EX_RDONLY(exp) || __mnt_is_readonly(exp->mnt)) + if (EX_RDONLY(exp) || __mnt_is_readonly(exp->ex_mnt)) return nfserr_rofs; if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode)) return nfserr_perm; Index: 2.6.22-rc4-mm2-robindmount/net/unix/af_unix.c =================================================================== --- 2.6.22-rc4-mm2-robindmount.orig/net/unix/af_unix.c +++ 2.6.22-rc4-mm2-robindmount/net/unix/af_unix.c @@ -815,7 +815,11 @@ static int unix_bind(struct socket *sock */ mode = S_IFSOCK | (SOCK_INODE(sock)->i_mode & ~current->fs->umask); + err = mnt_want_write(nd.mnt); + if (err) + goto out_mknod_dput; err = vfs_mknod(nd.dentry->d_inode, dentry, mode, 0); + mnt_drop_write(nd.mnt); if (err) goto out_mknod_dput; mutex_unlock(&nd.dentry->d_inode->i_mutex); -- _______________________________________________ Containers mailing list Containers@lists.linux-foundation.org https://lists.linux-foundation.org/mailman/listinfo/containers