[PATCH v4 19/26] NFS: Split nfs_parse_mount_options()

Scott Mayhew
2019-09-13T12:19:14Z

From: David Howells <dhowells@redhat.com>

Split nfs_parse_mount_options() to move the prologue, list-splitting and
epilogue into one function and the per-option processing into another.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/nfs/fs_context.c | 126 ++++++++++++++++++++++++--------------------
fs/nfs/internal.h | 3 ++
2 files changed, 73 insertions(+), 56 deletions(-)

diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
index 63aa5faed9da..3ad8fc68e623 100644
--- a/fs/nfs/fs_context.c
+++ b/fs/nfs/fs_context.c
@@ -496,36 +496,18 @@ static int nfs_get_option_ul_bound(substring_t args[], unsigned long *option,
}

/*
- * Error-check and convert a string of mount options from user space into
- * a data structure. The whole mount string is processed; bad options are
- * skipped as they are encountered. If there were no errors, return 1;
- * otherwise return 0 (zero).
+ * Parse a single mount option in "key[=val]" form.
*/
-int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
+static int nfs_fs_context_parse_option(struct nfs_fs_context *ctx, char *p)
{
- char *p, *string;
- int rc, sloppy = 0, invalid_option = 0;
- unsigned short protofamily = AF_UNSPEC;
- unsigned short mountfamily = AF_UNSPEC;
-
- if (!raw) {
- dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
- return 1;
- }
- dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
-
- rc = security_sb_eat_lsm_opts(raw, &ctx->lsm_opts);
- if (rc)
- goto out_security_failure;
+ char *string;
+ int rc;

- while ((p = strsep(&raw, ",")) != NULL) {
+ {
substring_t args[MAX_OPT_ARGS];
unsigned long option;
int token;

- if (!*p)
- continue;
-
dfprintk(MOUNT, "NFS: parsing nfs mount option '%s'\n", p);

token = match_token(p, nfs_mount_option_tokens, args);
@@ -734,7 +716,7 @@ int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
if (!rc) {
dfprintk(MOUNT, "NFS: unrecognized "
"security flavor\n");
- return 0;
+ return -EINVAL;
}
break;
case Opt_proto:
@@ -744,24 +726,24 @@ int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
token = match_token(string,
nfs_xprt_protocol_tokens, args);

- protofamily = AF_INET;
+ ctx->protofamily = AF_INET;
switch (token) {
case Opt_xprt_udp6:
- protofamily = AF_INET6;
+ ctx->protofamily = AF_INET6;
/* fall through */
case Opt_xprt_udp:
ctx->flags &= ~NFS_MOUNT_TCP;
ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
break;
case Opt_xprt_tcp6:
- protofamily = AF_INET6;
+ ctx->protofamily = AF_INET6;
/* fall through */
case Opt_xprt_tcp:
ctx->flags |= NFS_MOUNT_TCP;
ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
break;
case Opt_xprt_rdma6:
- protofamily = AF_INET6;
+ ctx->protofamily = AF_INET6;
/* fall through */
case Opt_xprt_rdma:
/* vector side protocols to TCP */
@@ -773,7 +755,7 @@ int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
dfprintk(MOUNT, "NFS: unrecognized "
"transport protocol\n");
kfree(string);
- return 0;
+ return -EINVAL;
}
kfree(string);
break;
@@ -785,16 +767,16 @@ int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
nfs_xprt_protocol_tokens, args);
kfree(string);

- mountfamily = AF_INET;
+ ctx->mountfamily = AF_INET;
switch (token) {
case Opt_xprt_udp6:
- mountfamily = AF_INET6;
+ ctx->mountfamily = AF_INET6;
/* fall through */
case Opt_xprt_udp:
ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
break;
case Opt_xprt_tcp6:
- mountfamily = AF_INET6;
+ ctx->mountfamily = AF_INET6;
/* fall through */
case Opt_xprt_tcp:
ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
@@ -803,7 +785,7 @@ int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
default:
dfprintk(MOUNT, "NFS: unrecognized "
"transport protocol\n");
- return 0;
+ return -EINVAL;
}
break;
case Opt_addr:
@@ -867,7 +849,7 @@ int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
default:
dfprintk(MOUNT, "NFS: invalid "
"lookupcache argument\n");
- return 0;
+ return -EINVAL;
};
break;
case Opt_fscache_uniq:
@@ -900,7 +882,7 @@ int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
default:
dfprintk(MOUNT, "NFS: invalid "
"local_lock argument\n");
- return 0;
+ return -EINVAL;
};
break;

@@ -908,7 +890,7 @@ int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
* Special options
*/
case Opt_sloppy:
- sloppy = 1;
+ ctx->sloppy = 1;
dfprintk(MOUNT, "NFS: relaxing parsing rules\n");
break;
case Opt_userspace:
@@ -918,12 +900,53 @@ int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
break;

default:
- invalid_option = 1;
dfprintk(MOUNT, "NFS: unrecognized mount option "
"'%s'\n", p);
+ return -EINVAL;
}
}

+ return 0;
+
+out_invalid_address:
+ printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
+ return -EINVAL;
+out_invalid_value:
+ printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
+ return -EINVAL;
+out_nomem:
+ printk(KERN_INFO "NFS: not enough memory to parse option\n");
+ return -ENOMEM;
+}
+
+/*
+ * Error-check and convert a string of mount options from user space into
+ * a data structure. The whole mount string is processed; bad options are
+ * skipped as they are encountered. If there were no errors, return 1;
+ * otherwise return 0 (zero).
+ */
+int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
+{
+ char *p;
+ int rc, sloppy = 0, invalid_option = 0;
+
+ if (!raw) {
+ dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
+ return 1;
+ }
+ dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
+
+ rc = security_sb_eat_lsm_opts(raw, &ctx->lsm_opts);
+ if (rc)
+ goto out_security_failure;
+
+ while ((p = strsep(&raw, ",")) != NULL) {
+ if (!*p)
+ continue;
+ if (nfs_fs_context_parse_option(ctx, p) < 0)
+ invalid_option = true;
+ }
+
if (!sloppy && invalid_option)
return 0;

@@ -938,22 +961,26 @@ int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
* verify that any proto=/mountproto= options match the address
* families in the addr=/mountaddr= options.
*/
- if (protofamily != AF_UNSPEC &&
- protofamily != ctx->nfs_server.address.ss_family)
+ if (ctx->protofamily != AF_UNSPEC &&
+ ctx->protofamily != ctx->nfs_server.address.ss_family)
goto out_proto_mismatch;

- if (mountfamily != AF_UNSPEC) {
+ if (ctx->mountfamily != AF_UNSPEC) {
if (ctx->mount_server.addrlen) {
- if (mountfamily != ctx->mount_server.address.ss_family)
+ if (ctx->mountfamily != ctx->mount_server.address.ss_family)
goto out_mountproto_mismatch;
} else {
- if (mountfamily != ctx->nfs_server.address.ss_family)
+ if (ctx->mountfamily != ctx->nfs_server.address.ss_family)
goto out_mountproto_mismatch;
}
}

return 1;

+out_minorversion_mismatch:
+ printk(KERN_INFO "NFS: mount option vers=%u does not support "
+ "minorversion=%u\n", ctx->version, ctx->minorversion);
+ return 0;
out_mountproto_mismatch:
printk(KERN_INFO "NFS: mount server address does not match mountproto= "
"option\n");
@@ -961,23 +988,10 @@ int nfs_parse_mount_options(char *raw, struct nfs_fs_context *ctx)
out_proto_mismatch:
printk(KERN_INFO "NFS: server address does not match proto= option\n");
return 0;
-out_invalid_address:
- printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
- return 0;
-out_invalid_value:
- printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
- return 0;
-out_minorversion_mismatch:
- printk(KERN_INFO "NFS: mount option vers=%u does not support "
- "minorversion=%u\n", ctx->version, ctx->minorversion);
- return 0;
out_migration_misuse:
printk(KERN_INFO
"NFS: 'migration' not supported for this NFS version\n");
- return 0;
-out_nomem:
- printk(KERN_INFO "NFS: not enough memory to parse option\n");
- return 0;
+ return -EINVAL;
out_security_failure:
printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
return 0;
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 632174d666a8..d084182f8e43 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -104,7 +104,10 @@ struct nfs_fs_context {
unsigned int version;
unsigned int minorversion;
char *fscache_uniq;
+ unsigned short protofamily;
+ unsigned short mountfamily;
bool need_mount;
+ bool sloppy;

struct {
struct sockaddr_storage address;
--
2.17.2