NFS: Add a mount option "softerr" to allow clients to see ETIMEDOUT e…

…rrors Add a mount option that exposes the ETIMEDOUT errors that occur during soft timeouts to the application. This allows aware applications to distinguish between server disk IO errors and client timeout errors. Signed-off-by: Trond Myklebust <[email protected]> Signed-off-by: Anna Schumaker <[email protected]>
jangid · Apr 25, 2019 · 91a575e · 91a575e
1 parent 7b1355b
commit 91a575e
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Showing 3 changed files with 15 additions and 3 deletions.
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
@@ -598,6 +598,8 @@ int nfs_init_server_rpcclient(struct nfs_server *server,
 			sizeof(server->client->cl_timeout_default));
 	server->client->cl_timeout = &server->client->cl_timeout_default;
 	server->client->cl_softrtry = 0;
+	if (server->flags & NFS_MOUNT_SOFTERR)
+		server->client->cl_softerr = 1;
 	if (server->flags & NFS_MOUNT_SOFT)
 		server->client->cl_softrtry = 1;
 

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
@@ -78,7 +78,7 @@
 
 enum {
 	/* Mount options that take no arguments */
-	Opt_soft, Opt_hard,
+	Opt_soft, Opt_softerr, Opt_hard,
 	Opt_posix, Opt_noposix,
 	Opt_cto, Opt_nocto,
 	Opt_ac, Opt_noac,
@@ -125,6 +125,7 @@ static const match_table_t nfs_mount_option_tokens = {
 	{ Opt_sloppy, "sloppy" },
 
 	{ Opt_soft, "soft" },
+	{ Opt_softerr, "softerr" },
 	{ Opt_hard, "hard" },
 	{ Opt_deprecated, "intr" },
 	{ Opt_deprecated, "nointr" },
@@ -628,7 +629,8 @@ static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 		const char *str;
 		const char *nostr;
 	} nfs_info[] = {
-		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
+		{ NFS_MOUNT_SOFT, ",soft", "" },
+		{ NFS_MOUNT_SOFTERR, ",softerr", "" },
 		{ NFS_MOUNT_POSIX, ",posix", "" },
 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
 		{ NFS_MOUNT_NOAC, ",noac", "" },
@@ -658,6 +660,8 @@ static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
+	if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR)))
+			seq_puts(m, ",hard");
 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
 		if (nfss->flags & nfs_infop->flag)
 			seq_puts(m, nfs_infop->str);
@@ -1239,10 +1243,15 @@ static int nfs_parse_mount_options(char *raw,
 		 */
 		case Opt_soft:
 			mnt->flags |= NFS_MOUNT_SOFT;
+			mnt->flags &= ~NFS_MOUNT_SOFTERR;
 			break;
-		case Opt_hard:
+		case Opt_softerr:
+			mnt->flags |= NFS_MOUNT_SOFTERR;
 			mnt->flags &= ~NFS_MOUNT_SOFT;
 			break;
+		case Opt_hard:
+			mnt->flags &= ~(NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR);
+			break;
 		case Opt_posix:
 			mnt->flags |= NFS_MOUNT_POSIX;
 			break;

diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
@@ -147,6 +147,7 @@ struct nfs_server {
 #define NFS_MOUNT_LEGACY_INTERFACE	0x80000
 #define NFS_MOUNT_LOCAL_FLOCK		0x100000
 #define NFS_MOUNT_LOCAL_FCNTL		0x200000
+#define NFS_MOUNT_SOFTERR		0x400000
 
 	unsigned int		caps;		/* server capabilities */
 	unsigned int		rsize;		/* read size */