Specifying the serverfailed mount option causes all subsequent RPC tasks
that are queued to fail with -EIO instead of timing out. For example, if
a server has disappeared, the sequence:
mount -o remount,serverfailed
umount -f
will ensure that all pending I/O requests are cancelled, and any new
requests will also fail. In the event that the server returns, the flag
can be removed with a remount:
mount -o remount,noserverfailed
Although bringing the server back may result in a loss of data
Signed-off-by: Joshua Watt <JPEWhacker@xxxxxxxxx>
---
fs/nfs/inode.c | 6 ++++++
fs/nfs/super.c | 30 +++++++++++++++++++++++++-----
include/uapi/linux/nfs_mount.h | 1 +
3 files changed, 32 insertions(+), 5 deletions(-)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 134d9f560240..55b7cd40508d 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -723,6 +723,12 @@ static void nfs_readdirplus_parent_cache_hit(struct dentry *dentry)
static bool nfs_need_revalidate_inode(struct inode *inode)
{
+ /* If the server has failed, it is not going to respond, so don't try
+ * and revalidated (otherwise, the serverfailed flag can't be cleared by
+ * a remount)
+ */
+ if (NFS_SERVER(inode)->flags & NFS_MOUNT_SERVERFAILED)
+ return false;
if (NFS_I(inode)->cache_validity &
(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
return true;
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 777a0cc22704..bca38e1cdd85 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -90,6 +90,7 @@ enum {
Opt_resvport, Opt_noresvport,
Opt_fscache, Opt_nofscache,
Opt_migration, Opt_nomigration,
+ Opt_serverfailed, Opt_noserverfailed,
/* Mount options that take integer arguments */
Opt_port,
@@ -151,6 +152,8 @@ static const match_table_t nfs_mount_option_tokens = {
{ Opt_nofscache, "nofsc" },
{ Opt_migration, "migration" },
{ Opt_nomigration, "nomigration" },
+ { Opt_serverfailed, "serverfailed" },
+ { Opt_noserverfailed, "noserverfailed" },
{ Opt_port, "port=%s" },
{ Opt_rsize, "rsize=%s" },
@@ -637,6 +640,7 @@ static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
+ { NFS_MOUNT_SERVERFAILED, ",serverfailed", "" },
{ 0, NULL, NULL }
};
const struct proc_nfs_info *nfs_infop;
@@ -1330,6 +1334,11 @@ static int nfs_parse_mount_options(char *raw,
case Opt_nomigration:
mnt->options &= ~NFS_OPTION_MIGRATION;
break;
+ case Opt_serverfailed:
+ case Opt_noserverfailed:
+ set_flag(mnt, NFS_MOUNT_SERVERFAILED,
+ token == Opt_serverfailed);
+ break;
/*
* options that take numeric values
@@ -2192,6 +2201,8 @@ static int nfs_validate_text_mount_data(void *options,
return -EINVAL;
}
+#define NFS_REMOUNT_CHANGE_FLAGS (NFS_MOUNT_SERVERFAILED)
+
#define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
| NFS_MOUNT_SECURE \
| NFS_MOUNT_TCP \
@@ -2200,7 +2211,8 @@ static int nfs_validate_text_mount_data(void *options,
| NFS_MOUNT_NONLM \
| NFS_MOUNT_BROKEN_SUID \
| NFS_MOUNT_STRICTLOCK \
- | NFS_MOUNT_LEGACY_INTERFACE)
+ | NFS_MOUNT_LEGACY_INTERFACE \
+ | NFS_REMOUNT_CHANGE_FLAGS)
#define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
@@ -2209,12 +2221,15 @@ static int
nfs_compare_and_set_remount_data(struct nfs_server *nfss,
struct nfs_parsed_mount_data *data)
{
+ int changed_flags_mask = data->flags_mask & NFS_REMOUNT_CHANGE_FLAGS;
+ struct rpc_clnt *cl = nfss->client;
+
if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
data->rsize != nfss->rsize ||
data->wsize != nfss->wsize ||
data->version != nfss->nfs_client->rpc_ops->version ||
data->minorversion != nfss->nfs_client->cl_minorversion ||
- !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
+ !nfs_auth_info_match(&data->auth_info, cl->cl_auth->au_flavor) ||
data->acregmin != nfss->acregmin / HZ ||
data->acregmax != nfss->acregmax / HZ ||
data->acdirmin != nfss->acdirmin / HZ ||
@@ -2225,13 +2240,16 @@ nfs_compare_and_set_remount_data(struct nfs_server *nfss,
(struct sockaddr *)&nfss->nfs_client->cl_addr))
return -EINVAL;
- if (data->retrans != nfss->client->cl_timeout->to_retries ||
- data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ)) {
+ /* Update flags */
+ nfss->flags = (nfss->flags & ~changed_flags_mask) |
+ (data->flags & changed_flags_mask);
+
+ if (data->retrans != cl->cl_timeout->to_retries ||
+ data->timeo != (10U * cl->cl_timeout->to_initval / HZ)) {
/* Note that this will affect all mounts from the same server,
* that use the same protocol. The timeouts are always forced
* to be the same.
*/
- struct rpc_clnt *cl = nfss->client;
if (cl->cl_timeout != &cl->cl_timeout_default)
memcpy(&cl->cl_timeout_default, cl->cl_timeout,
sizeof(struct rpc_timeout));
@@ -2239,6 +2257,8 @@ nfs_compare_and_set_remount_data(struct nfs_server *nfss,
cl->cl_timeout_default.to_initval = data->timeo * HZ / 10U;
}
+ cl->cl_kill_new_tasks = !!(nfss->flags & NFS_MOUNT_SERVERFAILED);
+
return 0;
}
diff --git a/include/uapi/linux/nfs_mount.h b/include/uapi/linux/nfs_mount.h
index e44e00616ab5..8ad931cdca20 100644
--- a/include/uapi/linux/nfs_mount.h
+++ b/include/uapi/linux/nfs_mount.h
@@ -74,5 +74,6 @@ struct nfs_mount_data {
#define NFS_MOUNT_LOCAL_FLOCK 0x100000
#define NFS_MOUNT_LOCAL_FCNTL 0x200000
+#define NFS_MOUNT_SERVERFAILED 0x400000
#endif
--
2.13.6
--
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