libceph, rbd, ceph: convert to use the new mount API

Convert the ceph filesystem to the new internal mount API as the old
one will be obsoleted and removed.  This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.

See Documentation/filesystems/mount_api.txt for more information.

[ Numerous string handling, leak and regression fixes; rbd conversion
  was particularly broken and had to be redone almost from scratch. ]

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 153 insertions, 109 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 3a40b5f60810..2b184563cd32 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -34,7 +34,7 @@
 #include <linux/ceph/cls_lock_client.h>
 #include <linux/ceph/striper.h>
 #include <linux/ceph/decode.h>
-#include <linux/parser.h>
+#include <linux/fs_parser.h>
 #include <linux/bsearch.h>
 
 #include <linux/kernel.h>
@@ -838,34 +838,34 @@ enum {
 	Opt_queue_depth,
 	Opt_alloc_size,
 	Opt_lock_timeout,
-	Opt_last_int,
 	/* int args above */
 	Opt_pool_ns,
-	Opt_last_string,
 	/* string args above */
 	Opt_read_only,
 	Opt_read_write,
 	Opt_lock_on_read,
 	Opt_exclusive,
 	Opt_notrim,
-	Opt_err
 };
 
-static match_table_t rbd_opts_tokens = {
-	{Opt_queue_depth, "queue_depth=%d"},
-	{Opt_alloc_size, "alloc_size=%d"},
-	{Opt_lock_timeout, "lock_timeout=%d"},
-	/* int args above */
-	{Opt_pool_ns, "_pool_ns=%s"},
-	/* string args above */
-	{Opt_read_only, "read_only"},
-	{Opt_read_only, "ro"},		/* Alternate spelling */
-	{Opt_read_write, "read_write"},
-	{Opt_read_write, "rw"},		/* Alternate spelling */
-	{Opt_lock_on_read, "lock_on_read"},
-	{Opt_exclusive, "exclusive"},
-	{Opt_notrim, "notrim"},
-	{Opt_err, NULL}
+static const struct fs_parameter_spec rbd_param_specs[] = {
+	fsparam_u32	("alloc_size",			Opt_alloc_size),
+	fsparam_flag	("exclusive",			Opt_exclusive),
+	fsparam_flag	("lock_on_read",		Opt_lock_on_read),
+	fsparam_u32	("lock_timeout",		Opt_lock_timeout),
+	fsparam_flag	("notrim",			Opt_notrim),
+	fsparam_string	("_pool_ns",			Opt_pool_ns),
+	fsparam_u32	("queue_depth",			Opt_queue_depth),
+	fsparam_flag	("read_only",			Opt_read_only),
+	fsparam_flag	("read_write",			Opt_read_write),
+	fsparam_flag	("ro",				Opt_read_only),
+	fsparam_flag	("rw",				Opt_read_write),
+	{}
+};
+
+static const struct fs_parameter_description rbd_parameters = {
+	.name		= "rbd",
+	.specs		= rbd_param_specs,
 };
 
 struct rbd_options {
@@ -886,87 +886,12 @@ struct rbd_options {
 #define RBD_EXCLUSIVE_DEFAULT	false
 #define RBD_TRIM_DEFAULT	true
 
-struct parse_rbd_opts_ctx {
+struct rbd_parse_opts_ctx {
 	struct rbd_spec		*spec;
+	struct ceph_options	*copts;
 	struct rbd_options	*opts;
 };
 
-static int parse_rbd_opts_token(char *c, void *private)
-{
-	struct parse_rbd_opts_ctx *pctx = private;
-	substring_t argstr[MAX_OPT_ARGS];
-	int token, intval, ret;
-
-	token = match_token(c, rbd_opts_tokens, argstr);
-	if (token < Opt_last_int) {
-		ret = match_int(&argstr[0], &intval);
-		if (ret < 0) {
-			pr_err("bad option arg (not int) at '%s'\n", c);
-			return ret;
-		}
-		dout("got int token %d val %d\n", token, intval);
-	} else if (token > Opt_last_int && token < Opt_last_string) {
-		dout("got string token %d val %s\n", token, argstr[0].from);
-	} else {
-		dout("got token %d\n", token);
-	}
-
-	switch (token) {
-	case Opt_queue_depth:
-		if (intval < 1) {
-			pr_err("queue_depth out of range\n");
-			return -EINVAL;
-		}
-		pctx->opts->queue_depth = intval;
-		break;
-	case Opt_alloc_size:
-		if (intval < SECTOR_SIZE) {
-			pr_err("alloc_size out of range\n");
-			return -EINVAL;
-		}
-		if (!is_power_of_2(intval)) {
-			pr_err("alloc_size must be a power of 2\n");
-			return -EINVAL;
-		}
-		pctx->opts->alloc_size = intval;
-		break;
-	case Opt_lock_timeout:
-		/* 0 is "wait forever" (i.e. infinite timeout) */
-		if (intval < 0 || intval > INT_MAX / 1000) {
-			pr_err("lock_timeout out of range\n");
-			return -EINVAL;
-		}
-		pctx->opts->lock_timeout = msecs_to_jiffies(intval * 1000);
-		break;
-	case Opt_pool_ns:
-		kfree(pctx->spec->pool_ns);
-		pctx->spec->pool_ns = match_strdup(argstr);
-		if (!pctx->spec->pool_ns)
-			return -ENOMEM;
-		break;
-	case Opt_read_only:
-		pctx->opts->read_only = true;
-		break;
-	case Opt_read_write:
-		pctx->opts->read_only = false;
-		break;
-	case Opt_lock_on_read:
-		pctx->opts->lock_on_read = true;
-		break;
-	case Opt_exclusive:
-		pctx->opts->exclusive = true;
-		break;
-	case Opt_notrim:
-		pctx->opts->trim = false;
-		break;
-	default:
-		/* libceph prints "bad option" msg */
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
 static char* obj_op_name(enum obj_operation_type op_type)
 {
 	switch (op_type) {
@@ -6423,6 +6348,122 @@ static inline char *dup_token(const char **buf, size_t *lenp)
 	return dup;
 }
 
+static int rbd_parse_param(struct fs_parameter *param,
+			    struct rbd_parse_opts_ctx *pctx)
+{
+	struct rbd_options *opt = pctx->opts;
+	struct fs_parse_result result;
+	int token, ret;
+
+	ret = ceph_parse_param(param, pctx->copts, NULL);
+	if (ret != -ENOPARAM)
+		return ret;
+
+	token = fs_parse(NULL, &rbd_parameters, param, &result);
+	dout("%s fs_parse '%s' token %d\n", __func__, param->key, token);
+	if (token < 0) {
+		if (token == -ENOPARAM) {
+			return invalf(NULL, "rbd: Unknown parameter '%s'",
+				      param->key);
+		}
+		return token;
+	}
+
+	switch (token) {
+	case Opt_queue_depth:
+		if (result.uint_32 < 1)
+			goto out_of_range;
+		opt->queue_depth = result.uint_32;
+		break;
+	case Opt_alloc_size:
+		if (result.uint_32 < SECTOR_SIZE)
+			goto out_of_range;
+		if (!is_power_of_2(result.uint_32)) {
+			return invalf(NULL, "rbd: alloc_size must be a power of 2");
+		}
+		opt->alloc_size = result.uint_32;
+		break;
+	case Opt_lock_timeout:
+		/* 0 is "wait forever" (i.e. infinite timeout) */
+		if (result.uint_32 > INT_MAX / 1000)
+			goto out_of_range;
+		opt->lock_timeout = msecs_to_jiffies(result.uint_32 * 1000);
+		break;
+	case Opt_pool_ns:
+		kfree(pctx->spec->pool_ns);
+		pctx->spec->pool_ns = param->string;
+		param->string = NULL;
+		break;
+	case Opt_read_only:
+		opt->read_only = true;
+		break;
+	case Opt_read_write:
+		opt->read_only = false;
+		break;
+	case Opt_lock_on_read:
+		opt->lock_on_read = true;
+		break;
+	case Opt_exclusive:
+		opt->exclusive = true;
+		break;
+	case Opt_notrim:
+		opt->trim = false;
+		break;
+	default:
+		BUG();
+	}
+
+	return 0;
+
+out_of_range:
+	return invalf(NULL, "rbd: %s out of range", param->key);
+}
+
+/*
+ * This duplicates most of generic_parse_monolithic(), untying it from
+ * fs_context and skipping standard superblock and security options.
+ */
+static int rbd_parse_options(char *options, struct rbd_parse_opts_ctx *pctx)
+{
+	char *key;
+	int ret = 0;
+
+	dout("%s '%s'\n", __func__, options);
+	while ((key = strsep(&options, ",")) != NULL) {
+		if (*key) {
+			struct fs_parameter param = {
+				.key	= key,
+				.type	= fs_value_is_string,
+			};
+			char *value = strchr(key, '=');
+			size_t v_len = 0;
+
+			if (value) {
+				if (value == key)
+					continue;
+				*value++ = 0;
+				v_len = strlen(value);
+			}
+
+
+			if (v_len > 0) {
+				param.string = kmemdup_nul(value, v_len,
+							   GFP_KERNEL);
+				if (!param.string)
+					return -ENOMEM;
+			}
+			param.size = v_len;
+
+			ret = rbd_parse_param(&param, pctx);
+			kfree(param.string);
+			if (ret)
+				break;
+		}
+	}
+
+	return ret;
+}
+
 /*
  * Parse the options provided for an "rbd add" (i.e., rbd image
  * mapping) request.  These arrive via a write to /sys/bus/rbd/add,
@@ -6474,8 +6515,7 @@ static int rbd_add_parse_args(const char *buf,
 	const char *mon_addrs;
 	char *snap_name;
 	size_t mon_addrs_size;
-	struct parse_rbd_opts_ctx pctx = { 0 };
-	struct ceph_options *copts;
+	struct rbd_parse_opts_ctx pctx = { 0 };
 	int ret;
 
 	/* The first four tokens are required */
@@ -6486,7 +6526,7 @@ static int rbd_add_parse_args(const char *buf,
 		return -EINVAL;
 	}
 	mon_addrs = buf;
-	mon_addrs_size = len + 1;
+	mon_addrs_size = len;
 	buf += len;
 
 	ret = -EINVAL;
@@ -6536,6 +6576,10 @@ static int rbd_add_parse_args(const char *buf,
 	*(snap_name + len) = '\0';
 	pctx.spec->snap_name = snap_name;
 
+	pctx.copts = ceph_alloc_options();
+	if (!pctx.copts)
+		goto out_mem;
+
 	/* Initialize all rbd options to the defaults */
 
 	pctx.opts = kzalloc(sizeof(*pctx.opts), GFP_KERNEL);
@@ -6550,27 +6594,27 @@ static int rbd_add_parse_args(const char *buf,
 	pctx.opts->exclusive = RBD_EXCLUSIVE_DEFAULT;
 	pctx.opts->trim = RBD_TRIM_DEFAULT;
 
-	copts = ceph_parse_options(options, mon_addrs,
-				   mon_addrs + mon_addrs_size - 1,
-				   parse_rbd_opts_token, &pctx);
-	if (IS_ERR(copts)) {
-		ret = PTR_ERR(copts);
+	ret = ceph_parse_mon_ips(mon_addrs, mon_addrs_size, pctx.copts, NULL);
+	if (ret)
 		goto out_err;
-	}
-	kfree(options);
 
-	*ceph_opts = copts;
+	ret = rbd_parse_options(options, &pctx);
+	if (ret)
+		goto out_err;
+
+	*ceph_opts = pctx.copts;
 	*opts = pctx.opts;
 	*rbd_spec = pctx.spec;
-
+	kfree(options);
 	return 0;
+
 out_mem:
 	ret = -ENOMEM;
 out_err:
 	kfree(pctx.opts);
+	ceph_destroy_options(pctx.copts);
 	rbd_spec_put(pctx.spec);
 	kfree(options);
-
 	return ret;
 }