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Message-ID: <155301262572.7556.18189698725705132181.stgit@warthog.procyon.org.uk>
Date: Tue, 19 Mar 2019 16:23:45 +0000
From: David Howells <dhowells@...hat.com>
To: miklos@...redi.hu, viro@...iv.linux.org.uk
Cc: linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
dhowells@...hat.com, anprice@...hat.com
Subject: [RFC PATCH 3/4] fuse: Convert to mount API
---
fs/fuse/inode.c | 272 ++++++++++++++++++++++++++++++-------------------------
1 file changed, 147 insertions(+), 125 deletions(-)
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index ec5d9953dfb6..3aebff5b902a 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -15,7 +15,8 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
#include <linux/statfs.h>
#include <linux/random.h>
#include <linux/sched.h>
@@ -59,7 +60,12 @@ MODULE_PARM_DESC(max_user_congthresh,
/** Congestion starts at 75% of maximum */
#define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
-struct fuse_mount_data {
+#ifdef CONFIG_BLOCK
+static struct file_system_type fuseblk_fs_type;
+#endif
+
+struct fuse_fs_context {
+ bool is_bdev;
int fd;
unsigned rootmode;
kuid_t user_id;
@@ -448,6 +454,7 @@ static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
}
enum {
+ OPT_SOURCE,
OPT_FD,
OPT_ROOTMODE,
OPT_USER_ID,
@@ -459,111 +466,97 @@ enum {
OPT_ERR
};
-static const match_table_t tokens = {
- {OPT_FD, "fd=%u"},
- {OPT_ROOTMODE, "rootmode=%o"},
- {OPT_USER_ID, "user_id=%u"},
- {OPT_GROUP_ID, "group_id=%u"},
- {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
- {OPT_ALLOW_OTHER, "allow_other"},
- {OPT_MAX_READ, "max_read=%u"},
- {OPT_BLKSIZE, "blksize=%u"},
- {OPT_ERR, NULL}
+static const struct fs_parameter_spec fuse_param_specs[] = {
+ fsparam_string ("source", OPT_SOURCE),
+ fsparam_fd ("fd", OPT_FD),
+ fsparam_u32oct ("rootmode", OPT_ROOTMODE),
+ fsparam_u32 ("user_id", OPT_USER_ID),
+ fsparam_u32 ("group_id", OPT_GROUP_ID),
+ fsparam_flag ("default_permissions", OPT_DEFAULT_PERMISSIONS),
+ fsparam_flag ("allow_other", OPT_ALLOW_OTHER),
+ fsparam_u32 ("max_read", OPT_MAX_READ),
+ fsparam_u32 ("blksize", OPT_BLKSIZE),
+ {}
};
-static int fuse_match_uint(substring_t *s, unsigned int *res)
+static const struct fs_parameter_description fuse_fs_parameters = {
+ .name = "fuse",
+ .specs = fuse_param_specs,
+};
+
+static int fuse_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
- int err = -ENOMEM;
- char *buf = match_strdup(s);
- if (buf) {
- err = kstrtouint(buf, 10, res);
- kfree(buf);
+ struct fs_parse_result result;
+ struct fuse_fs_context *ctx = fc->fs_private;
+ int opt;
+
+ opt = fs_parse(fc, &fuse_fs_parameters, param, &result);
+ if (opt < 0)
+ return opt;
+
+ switch (opt) {
+ case OPT_SOURCE:
+ kfree(fc->source);
+ fc->source = param->string;
+ param->string = NULL;
+ break;
+
+ case OPT_FD:
+ ctx->fd = result.uint_32;
+ ctx->fd_present = 1;
+ break;
+
+ case OPT_ROOTMODE:
+ if (!fuse_valid_type(result.uint_32))
+ return invalf(fc, "fuse: Invalid rootmode");
+ ctx->rootmode = result.uint_32;
+ ctx->rootmode_present = 1;
+ break;
+
+ case OPT_USER_ID:
+ ctx->user_id = make_kuid(fc->user_ns, result.uint_32);
+ if (!uid_valid(ctx->user_id))
+ return invalf(fc, "fuse: Invalid user_id");
+ ctx->user_id_present = 1;
+ break;
+
+ case OPT_GROUP_ID:
+ ctx->group_id = make_kgid(fc->user_ns, result.uint_32);
+ if (!gid_valid(ctx->group_id))
+ return invalf(fc, "fuse: Invalid group_id");
+ ctx->group_id_present = 1;
+ break;
+
+ case OPT_DEFAULT_PERMISSIONS:
+ ctx->default_permissions = 1;
+ break;
+
+ case OPT_ALLOW_OTHER:
+ ctx->allow_other = 1;
+ break;
+
+ case OPT_MAX_READ:
+ ctx->max_read = result.uint_32;
+ break;
+
+ case OPT_BLKSIZE:
+ if (!ctx->is_bdev)
+ return invalf(fc, "fuse: blksize only supported for fuseblk");
+ ctx->blksize = result.uint_32;
+ break;
+
+ default:
+ return -EINVAL;
}
- return err;
+
+ return 0;
}
-static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev,
- struct user_namespace *user_ns)
+static void fuse_free_fc(struct fs_context *fc)
{
- char *p;
- memset(d, 0, sizeof(struct fuse_mount_data));
- d->max_read = ~0;
- d->blksize = FUSE_DEFAULT_BLKSIZE;
-
- while ((p = strsep(&opt, ",")) != NULL) {
- int token;
- int value;
- unsigned uv;
- substring_t args[MAX_OPT_ARGS];
- if (!*p)
- continue;
-
- token = match_token(p, tokens, args);
- switch (token) {
- case OPT_FD:
- if (match_int(&args[0], &value))
- return 0;
- d->fd = value;
- d->fd_present = 1;
- break;
-
- case OPT_ROOTMODE:
- if (match_octal(&args[0], &value))
- return 0;
- if (!fuse_valid_type(value))
- return 0;
- d->rootmode = value;
- d->rootmode_present = 1;
- break;
-
- case OPT_USER_ID:
- if (fuse_match_uint(&args[0], &uv))
- return 0;
- d->user_id = make_kuid(user_ns, uv);
- if (!uid_valid(d->user_id))
- return 0;
- d->user_id_present = 1;
- break;
-
- case OPT_GROUP_ID:
- if (fuse_match_uint(&args[0], &uv))
- return 0;
- d->group_id = make_kgid(user_ns, uv);
- if (!gid_valid(d->group_id))
- return 0;
- d->group_id_present = 1;
- break;
-
- case OPT_DEFAULT_PERMISSIONS:
- d->default_permissions = 1;
- break;
-
- case OPT_ALLOW_OTHER:
- d->allow_other = 1;
- break;
-
- case OPT_MAX_READ:
- if (match_int(&args[0], &value))
- return 0;
- d->max_read = value;
- break;
-
- case OPT_BLKSIZE:
- if (!is_bdev || match_int(&args[0], &value))
- return 0;
- d->blksize = value;
- break;
-
- default:
- return 0;
- }
- }
-
- if (!d->fd_present || !d->rootmode_present ||
- !d->user_id_present || !d->group_id_present)
- return 0;
+ struct fuse_fs_context *ctx = fc->fs_private;
- return 1;
+ kfree(ctx);
}
static int fuse_show_options(struct seq_file *m, struct dentry *root)
@@ -1078,12 +1071,12 @@ void fuse_dev_free(struct fuse_dev *fud)
}
EXPORT_SYMBOL_GPL(fuse_dev_free);
-static int fuse_fill_super(struct super_block *sb, void *data, int silent)
+static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
{
+ struct fuse_fs_context *ctx = fsc->fs_private;
struct fuse_dev *fud;
struct fuse_conn *fc;
struct inode *root;
- struct fuse_mount_data d;
struct file *file;
struct dentry *root_dentry;
struct fuse_req *init_req;
@@ -1096,13 +1089,10 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION);
- if (!parse_fuse_opt(data, &d, is_bdev, sb->s_user_ns))
- goto err;
-
if (is_bdev) {
#ifdef CONFIG_BLOCK
err = -EINVAL;
- if (!sb_set_blocksize(sb, d.blksize))
+ if (!sb_set_blocksize(sb, ctx->blksize))
goto err;
#endif
} else {
@@ -1119,7 +1109,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
if (sb->s_user_ns != &init_user_ns)
sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER;
- file = fget(d.fd);
+ file = fget(ctx->fd);
err = -EINVAL;
if (!file)
goto err;
@@ -1162,17 +1152,17 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
fc->dont_mask = 1;
sb->s_flags |= SB_POSIXACL;
- fc->default_permissions = d.default_permissions;
- fc->allow_other = d.allow_other;
- fc->user_id = d.user_id;
- fc->group_id = d.group_id;
- fc->max_read = max_t(unsigned, 4096, d.max_read);
+ fc->default_permissions = ctx->default_permissions;
+ fc->allow_other = ctx->allow_other;
+ fc->user_id = ctx->user_id;
+ fc->group_id = ctx->group_id;
+ fc->max_read = max_t(unsigned, 4096, ctx->max_read);
/* Used by get_root_inode() */
sb->s_fs_info = fc;
err = -ENOMEM;
- root = fuse_get_root_inode(sb, d.rootmode);
+ root = fuse_get_root_inode(sb, ctx->rootmode);
sb->s_d_op = &fuse_root_dentry_operations;
root_dentry = d_make_root(root);
if (!root_dentry)
@@ -1232,11 +1222,48 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
return err;
}
-static struct dentry *fuse_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name,
- void *raw_data)
+static int fuse_get_tree(struct fs_context *fc)
+{
+ struct fuse_fs_context *ctx = fc->fs_private;
+
+ if (!ctx->fd_present || !ctx->rootmode_present ||
+ !ctx->user_id_present || !ctx->group_id_present)
+ return invalf(fc, "fuse: Missing mount parameter(s)");
+
+ if (ctx->is_bdev)
+ return vfs_get_block_super(fc, fuse_fill_super);
+
+ return vfs_get_super(fc, vfs_get_independent_super, fuse_fill_super);
+}
+
+static const struct fs_context_operations fuse_context_ops = {
+ .free = fuse_free_fc,
+ .parse_param = fuse_parse_param,
+ .get_tree = fuse_get_tree,
+};
+
+/*
+ * Set up the filesystem mount context.
+ */
+static int fuse_init_fs_context(struct fs_context *fc)
{
- return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
+ struct fuse_fs_context *ctx;
+
+ ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->max_read = ~0;
+ ctx->blksize = FUSE_DEFAULT_BLKSIZE;
+
+#ifdef CONFIG_BLOCK
+ if (fc->fs_type == &fuseblk_fs_type)
+ ctx->is_bdev = true;
+#endif
+
+ fc->fs_private = ctx;
+ fc->ops = &fuse_context_ops;
+ return 0;
}
static void fuse_sb_destroy(struct super_block *sb)
@@ -1265,19 +1292,13 @@ static struct file_system_type fuse_fs_type = {
.owner = THIS_MODULE,
.name = "fuse",
.fs_flags = FS_HAS_SUBTYPE | FS_USERNS_MOUNT,
- .mount = fuse_mount,
+ .init_fs_context = fuse_init_fs_context,
+ .parameters = &fuse_fs_parameters,
.kill_sb = fuse_kill_sb_anon,
};
MODULE_ALIAS_FS("fuse");
#ifdef CONFIG_BLOCK
-static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
- int flags, const char *dev_name,
- void *raw_data)
-{
- return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
-}
-
static void fuse_kill_sb_blk(struct super_block *sb)
{
fuse_sb_destroy(sb);
@@ -1287,7 +1308,8 @@ static void fuse_kill_sb_blk(struct super_block *sb)
static struct file_system_type fuseblk_fs_type = {
.owner = THIS_MODULE,
.name = "fuseblk",
- .mount = fuse_mount_blk,
+ .init_fs_context = fuse_init_fs_context,
+ .parameters = &fuse_fs_parameters,
.kill_sb = fuse_kill_sb_blk,
.fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
};
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