NFS: Add a small buffer in nfs_fs_context to avoid string dup

Add a small buffer in nfs_fs_context to avoid string duplication when
parsing numbers.  Also make the parsing function wrapper place the parsed
integer directly in the appropriate nfs_fs_context struct member.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
index 92a1e4b..2921c58 100644 (file)
--- a/fs/nfs/fs_context.c
+++ b/fs/nfs/fs_context.c
@@ -468,27 +468,38 @@ static int nfs_get_option_str(substring_t args[], char **option)
        return !*option;
 }
 
-static int nfs_get_option_ul(substring_t args[], unsigned long *option)
+static int nfs_get_option_ui(struct nfs_fs_context *ctx,
+                            substring_t args[], unsigned int *option)
 {
-       int rc;
-       char *string;
+       match_strlcpy(ctx->buf, args, sizeof(ctx->buf));
+       return kstrtouint(ctx->buf, 10, option);
+}
 
-       string = match_strdup(args);
-       if (string == NULL)
-               return -ENOMEM;
-       rc = kstrtoul(string, 10, option);
-       kfree(string);
+static int nfs_get_option_ui_bound(struct nfs_fs_context *ctx,
+                                  substring_t args[], unsigned int *option,
+                                  unsigned int l_bound, unsigned u_bound)
+{
+       int ret;
 
-       return rc;
+       match_strlcpy(ctx->buf, args, sizeof(ctx->buf));
+       ret = kstrtouint(ctx->buf, 10, option);
+       if (ret < 0)
+               return ret;
+       if (*option < l_bound || *option > u_bound)
+               return -ERANGE;
+       return 0;
 }
 
-static int nfs_get_option_ul_bound(substring_t args[], unsigned long *option,
-               unsigned long l_bound, unsigned long u_bound)
+static int nfs_get_option_us_bound(struct nfs_fs_context *ctx,
+                                  substring_t args[], unsigned short *option,
+                                  unsigned short l_bound,
+                                  unsigned short u_bound)
 {
        int ret;
 
-       ret = nfs_get_option_ul(args, option);
-       if (ret != 0)
+       match_strlcpy(ctx->buf, args, sizeof(ctx->buf));
+       ret = kstrtou16(ctx->buf, 10, option);
+       if (ret < 0)
                return ret;
        if (*option < l_bound || *option > u_bound)
                return -ERANGE;
@@ -501,7 +512,6 @@ static int nfs_get_option_ul_bound(substring_t args[], unsigned long *option,
 static int nfs_fs_context_parse_option(struct nfs_fs_context *ctx, char *p)
 {
        substring_t args[MAX_OPT_ARGS];
-       unsigned long option;
        char *string;
        int token, rc;
 
@@ -609,86 +619,70 @@ static int nfs_fs_context_parse_option(struct nfs_fs_context *ctx, char *p)
                 * options that take numeric values
                 */
        case Opt_port:
-               if (nfs_get_option_ul(args, &option) ||
-                   option > USHRT_MAX)
+               if (nfs_get_option_ui_bound(ctx, args, &ctx->nfs_server.port,
+                                           0, USHRT_MAX))
                        goto out_invalid_value;
-               ctx->nfs_server.port = option;
                break;
        case Opt_rsize:
-               if (nfs_get_option_ul(args, &option))
+               if (nfs_get_option_ui(ctx, args, &ctx->rsize))
                        goto out_invalid_value;
-               ctx->rsize = option;
                break;
        case Opt_wsize:
-               if (nfs_get_option_ul(args, &option))
+               if (nfs_get_option_ui(ctx, args, &ctx->wsize))
                        goto out_invalid_value;
-               ctx->wsize = option;
                break;
        case Opt_bsize:
-               if (nfs_get_option_ul(args, &option))
+               if (nfs_get_option_ui(ctx, args, &ctx->bsize))
                        goto out_invalid_value;
-               ctx->bsize = option;
                break;
        case Opt_timeo:
-               if (nfs_get_option_ul_bound(args, &option, 1, INT_MAX))
+               if (nfs_get_option_ui_bound(ctx, args, &ctx->timeo, 1, INT_MAX))
                        goto out_invalid_value;
-               ctx->timeo = option;
                break;
        case Opt_retrans:
-               if (nfs_get_option_ul_bound(args, &option, 0, INT_MAX))
+               if (nfs_get_option_ui_bound(ctx, args, &ctx->retrans, 0, INT_MAX))
                        goto out_invalid_value;
-               ctx->retrans = option;
                break;
        case Opt_acregmin:
-               if (nfs_get_option_ul(args, &option))
+               if (nfs_get_option_ui(ctx, args, &ctx->acregmin))
                        goto out_invalid_value;
-               ctx->acregmin = option;
                break;
        case Opt_acregmax:
-               if (nfs_get_option_ul(args, &option))
+               if (nfs_get_option_ui(ctx, args, &ctx->acregmax))
                        goto out_invalid_value;
-               ctx->acregmax = option;
                break;
        case Opt_acdirmin:
-               if (nfs_get_option_ul(args, &option))
+               if (nfs_get_option_ui(ctx, args, &ctx->acdirmin))
                        goto out_invalid_value;
-               ctx->acdirmin = option;
                break;
        case Opt_acdirmax:
-               if (nfs_get_option_ul(args, &option))
+               if (nfs_get_option_ui(ctx, args, &ctx->acdirmax))
                        goto out_invalid_value;
-               ctx->acdirmax = option;
                break;
        case Opt_actimeo:
-               if (nfs_get_option_ul(args, &option))
+               if (nfs_get_option_ui(ctx, args, &ctx->acdirmax))
                        goto out_invalid_value;
                ctx->acregmin = ctx->acregmax =
-                       ctx->acdirmin = ctx->acdirmax = option;
+                       ctx->acdirmin = ctx->acdirmax;
                break;
        case Opt_namelen:
-               if (nfs_get_option_ul(args, &option))
+               if (nfs_get_option_ui(ctx, args, &ctx->namlen))
                        goto out_invalid_value;
-               ctx->namlen = option;
                break;
        case Opt_mountport:
-               if (nfs_get_option_ul(args, &option) ||
-                   option > USHRT_MAX)
+               if (nfs_get_option_ui_bound(ctx, args, &ctx->mount_server.port,
+                                           0, USHRT_MAX))
                        goto out_invalid_value;
-               ctx->mount_server.port = option;
                break;
        case Opt_mountvers:
-               if (nfs_get_option_ul(args, &option) ||
-                   option < NFS_MNT_VERSION ||
-                   option > NFS_MNT3_VERSION)
+               if (nfs_get_option_ui_bound(ctx, args, &ctx->mount_server.version,
+                                           NFS_MNT_VERSION, NFS_MNT3_VERSION))
                        goto out_invalid_value;
-               ctx->mount_server.version = option;
                break;
        case Opt_minorversion:
-               if (nfs_get_option_ul(args, &option))
-                       goto out_invalid_value;
-               if (option > NFS4_MAX_MINOR_VERSION)
+               if (nfs_get_option_ui_bound(ctx, args, &ctx->minorversion,
+                                           0, NFS4_MAX_MINOR_VERSION))
                        goto out_invalid_value;
-               ctx->minorversion = option;
                break;
 
                /*
@@ -820,9 +814,9 @@ static int nfs_fs_context_parse_option(struct nfs_fs_context *ctx, char *p)
                        goto out_invalid_address;
                break;
        case Opt_nconnect:
-               if (nfs_get_option_ul_bound(args, &option, 1, NFS_MAX_CONNECTIONS))
+               if (nfs_get_option_us_bound(ctx, args, &ctx->nfs_server.nconnect,
+                                           1, NFS_MAX_CONNECTIONS))
                        goto out_invalid_value;
-               ctx->nfs_server.nconnect = option;
                break;
        case Opt_lookupcache:
                string = match_strdup(args);

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index d0abc7b..5342f3e 100644 (file)
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -122,6 +122,8 @@ struct nfs_fs_context {
 
        void                    *lsm_opts;
        struct net              *net;
+
+       char                    buf[32];        /* Parse buffer */
 };
 
 /* mount_clnt.c */