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From: David Howells <dhowells@redhat.com>
To: trond.myklebust@hammerspace.com, anna.schumaker@netapp.com
Cc: Al Viro <viro@zeniv.linux.org.uk>,
	dhowells@redhat.com, viro@zeniv.linux.org.uk,
	linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 21/23] NFS: Add a small buffer in nfs_fs_context to avoid string dup
Date: Thu, 23 May 2019 17:18:50 +0100	[thread overview]
Message-ID: <155862832993.26654.13644247168126569903.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <155862813755.26654.563679411147031501.stgit@warthog.procyon.org.uk>

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>
---

 fs/nfs/fs_context.c |   82 +++++++++++++++++++--------------------------------
 fs/nfs/internal.h   |    2 +
 2 files changed, 32 insertions(+), 52 deletions(-)

diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
index c7796fb76732..5ba534127c0b 100644
--- a/fs/nfs/fs_context.c
+++ b/fs/nfs/fs_context.c
@@ -467,27 +467,22 @@ 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;
-
-	string = match_strdup(args);
-	if (string == NULL)
-		return -ENOMEM;
-	rc = kstrtoul(string, 10, option);
-	kfree(string);
-
-	return rc;
+	match_strlcpy(ctx->buf, args, sizeof(ctx->buf));
+	return kstrtouint(ctx->buf, 10, option);
 }
 
-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_ui_bound(struct nfs_fs_context *ctx,
+				   substring_t args[], unsigned int *option,
+				   unsigned int l_bound, unsigned u_bound)
 {
 	int ret;
 
-	ret = nfs_get_option_ul(args, option);
-	if (ret != 0)
+	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;
@@ -500,7 +495,6 @@ 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;
 
@@ -608,86 +602,70 @@ 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;
 
 		/*
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index c4a1203163ba..6efdbedeeee8 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -129,6 +129,8 @@ struct nfs_fs_context {
 
 	void			*lsm_opts;
 	struct net		*net;
+
+	char			buf[32];	/* Parse buffer */
 };
 
 /* mount_clnt.c */


  parent reply	other threads:[~2019-05-23 16:18 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-23 16:15 [PATCH 00/23] nfs: Mount API conversion David Howells
2019-05-23 16:15 ` [PATCH 01/23] saner calling conventions for nfs_fs_mount_common() David Howells
2019-05-23 16:16 ` [PATCH 02/23] nfs: stash server into struct nfs_mount_info David Howells
2019-05-23 16:16 ` [PATCH 03/23] nfs: lift setting mount_info from nfs4_remote{, _referral}_mount David Howells
2019-05-23 16:16 ` [PATCH 04/23] nfs: fold nfs4_remote_fs_type and nfs4_remote_referral_fs_type David Howells
2019-05-23 16:16 ` [PATCH 05/23] nfs: don't bother setting/restoring export_path around do_nfs_root_mount() David Howells
2019-05-23 16:16 ` [PATCH 06/23] nfs4: fold nfs_do_root_mount/nfs_follow_remote_path David Howells
2019-05-23 16:16 ` [PATCH 07/23] nfs: lift setting mount_info from nfs_xdev_mount() David Howells
2019-05-23 16:17 ` [PATCH 08/23] nfs: stash nfs_subversion reference into nfs_mount_info David Howells
2019-05-23 16:17 ` [PATCH 09/23] nfs: don't bother passing nfs_subversion to ->try_mount() and nfs_fs_mount_common() David Howells
2019-05-23 16:17 ` [PATCH 10/23] nfs: merge xdev and remote file_system_type David Howells
2019-05-23 16:17 ` [PATCH 11/23] nfs: unexport nfs_fs_mount_common() David Howells
2019-05-23 16:17 ` [PATCH 12/23] nfs: don't pass nfs_subversion to ->create_server() David Howells
2019-05-23 16:17 ` [PATCH 13/23] nfs: get rid of mount_info ->fill_super() David Howells
2019-05-23 16:17 ` [PATCH 14/23] nfs_clone_sb_security(): simplify the check for server bogosity David Howells
2019-05-23 16:18 ` [PATCH 15/23] nfs: get rid of ->set_security() David Howells
2019-05-23 16:18 ` [PATCH 16/23] NFS: Move mount parameterisation bits into their own file David Howells
2019-05-23 16:18 ` [PATCH 17/23] NFS: Constify mount argument match tables David Howells
2019-05-23 16:18 ` [PATCH 18/23] NFS: Rename struct nfs_parsed_mount_data to struct nfs_fs_context David Howells
2019-05-23 16:18 ` [PATCH 19/23] NFS: Split nfs_parse_mount_options() David Howells
2019-05-23 16:18 ` [PATCH 20/23] NFS: Deindent nfs_fs_context_parse_option() David Howells
2019-05-23 16:18 ` David Howells [this message]
2019-05-23 16:18 ` [PATCH 22/23] NFS: Do some tidying of the parsing code David Howells
2019-05-23 16:19 ` [PATCH 23/23] NFS: Add fs_context support David Howells
2019-05-25 23:08   ` Al Viro
2019-05-29 21:18   ` Schumaker, Anna
2019-06-06  9:41   ` David Howells

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