diff options
| -rw-r--r-- | utils/mount/stropts.c | 67 |
1 files changed, 53 insertions, 14 deletions
diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c index c82ddfe..c5c4ba1 100644 --- a/utils/mount/stropts.c +++ b/utils/mount/stropts.c @@ -304,6 +304,16 @@ static int nfs_set_version(struct nfsmount_info *mi) mi->version = 4; /* + * Before 2.6.32, the kernel NFS client didn't + * support "-t nfs vers=4" mounts, so NFS version + * 4 cannot be included when autonegotiating + * while running on those kernels. + */ + if (mi->version == 0 && + linux_version_code() <= MAKE_VERSION(2, 6, 31)) + mi->version = 3; + + /* * If we still don't know, check for version-specific * mount options. */ @@ -746,6 +756,47 @@ static int nfs_try_mount_v4(struct nfsmount_info *mi) } /* + * Handle NFS version and transport protocol + * autonegotiation. + * + * When no version or protocol is specified on the + * command line, mount.nfs negotiates with the server + * to determine appropriate settings for the new + * mount point. + * + * Returns TRUE if successful, otherwise FALSE. + * "errno" is set to reflect the individual error. + */ +static int nfs_autonegotiate(struct nfsmount_info *mi) +{ + int result; + + result = nfs_try_mount_v4(mi); + if (result) + return result; + + switch (errno) { + case EPROTONOSUPPORT: + /* A clear indication that the server or our + * client does not support NFS version 4. */ + goto fall_back; + case ENOENT: + /* Legacy Linux servers don't export an NFS + * version 4 pseudoroot. */ + goto fall_back; + case EPERM: + /* Linux servers prior to 2.6.25 may return + * EPERM when NFS version 4 is not supported. */ + goto fall_back; + default: + return result; + } + +fall_back: + return nfs_try_mount_v3v2(mi); +} + +/* * This is a single pass through the fg/bg loop. * * Returns TRUE if successful, otherwise FALSE. @@ -757,20 +808,8 @@ static int nfs_try_mount(struct nfsmount_info *mi) switch (mi->version) { case 0: - if (linux_version_code() > MAKE_VERSION(2, 6, 31)) { - errno = 0; - result = nfs_try_mount_v4(mi); - if (errno != EPROTONOSUPPORT) { - /* - * To deal with legacy Linux servers that don't - * automatically export a pseudo root, retry - * ENOENT errors using version 3. And for - * Linux servers prior to 2.6.25, retry EPERM - */ - if (errno != ENOENT && errno != EPERM) - break; - } - } + result = nfs_autonegotiate(mi); + break; case 2: case 3: result = nfs_try_mount_v3v2(mi); |