* [PATCH 2/11] FUSE - core
@ 2005-01-11 16:25 Miklos Szeredi
2005-01-12 22:36 ` Andrew Morton
2005-01-14 13:55 ` Anton Altaparmakov
0 siblings, 2 replies; 11+ messages in thread
From: Miklos Szeredi @ 2005-01-11 16:25 UTC (permalink / raw)
To: akpm, torvalds; +Cc: linux-fsdevel, linux-kernel
This patch adds FUSE core.
This contains the following files:
o inode.c
- superblock operations (alloc_inode, destroy_inode, read_inode,
clear_inode, put_super, show_options)
- registers FUSE filesystem
o fuse_i.h
- private header file
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
diff -Nurp a/fs/fuse/Makefile b/fs/fuse/Makefile
--- a/fs/fuse/Makefile 1970-01-01 01:00:00.000000000 +0100
+++ b/fs/fuse/Makefile 2005-01-11 16:28:29.000000000 +0100
@@ -0,0 +1,7 @@
+#
+# Makefile for the FUSE filesystem.
+#
+
+obj-$(CONFIG_FUSE_FS) += fuse.o
+
+fuse-objs := inode.o
diff -Nurp a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
--- a/fs/fuse/fuse_i.h 1970-01-01 01:00:00.000000000 +0100
+++ b/fs/fuse/fuse_i.h 2005-01-11 16:28:29.000000000 +0100
@@ -0,0 +1,89 @@
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+#include <linux/fuse.h>
+#include <linux/fs.h>
+#include <linux/wait.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/backing-dev.h>
+#include <asm/semaphore.h>
+
+/** FUSE inode */
+struct fuse_inode {
+ /** Inode data */
+ struct inode inode;
+
+ /** Unique ID, which identifies the inode between userspace
+ * and kernel */
+ u64 nodeid;
+
+ /** Time in jiffies until the file attributes are valid */
+ unsigned long i_time;
+};
+
+/**
+ * A Fuse connection.
+ *
+ * This structure is created, when the filesystem is mounted, and is
+ * destroyed, when the client device is closed and the filesystem is
+ * unmounted.
+ */
+struct fuse_conn {
+ /** The superblock of the mounted filesystem */
+ struct super_block *sb;
+
+ /** The user id for this mount */
+ uid_t user_id;
+
+ /** Backing dev info */
+ struct backing_dev_info bdi;
+};
+
+static inline struct fuse_conn **get_fuse_conn_super_p(struct super_block *sb)
+{
+ return (struct fuse_conn **) &sb->s_fs_info;
+}
+
+static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
+{
+ return *get_fuse_conn_super_p(sb);
+}
+
+static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
+{
+ return get_fuse_conn_super(inode->i_sb);
+}
+
+static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
+{
+ return container_of(inode, struct fuse_inode, inode);
+}
+
+static inline u64 get_node_id(struct inode *inode)
+{
+ return get_fuse_inode(inode)->nodeid;
+}
+
+/**
+ * This is the single global spinlock which protects FUSE's structures
+ *
+ * The following data is protected by this lock:
+ *
+ * - the s_fs_info field of the super block
+ * - the sb (super_block) field in fuse_conn
+ */
+extern spinlock_t fuse_lock;
+
+/**
+ * Check if the connection can be released, and if yes, then free the
+ * connection structure
+ */
+void fuse_release_conn(struct fuse_conn *fc);
+
diff -Nurp a/fs/fuse/inode.c b/fs/fuse/inode.c
--- a/fs/fuse/inode.c 1970-01-01 01:00:00.000000000 +0100
+++ b/fs/fuse/inode.c 2005-01-11 16:28:29.000000000 +0100
@@ -0,0 +1,428 @@
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+#include "fuse_i.h"
+
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/mount.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/parser.h>
+#include <linux/statfs.h>
+
+MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
+MODULE_DESCRIPTION("Filesystem in Userspace");
+MODULE_LICENSE("GPL");
+
+spinlock_t fuse_lock;
+static kmem_cache_t *fuse_inode_cachep;
+static int mount_count;
+
+static int mount_max = 1000;
+module_param(mount_max, int, 0644);
+MODULE_PARM_DESC(mount_max, "Maximum number of FUSE mounts allowed, if -1 then unlimited (default: 1000)");
+
+#define FUSE_SUPER_MAGIC 0x65735546
+
+struct fuse_mount_data {
+ int fd;
+ unsigned rootmode;
+ unsigned user_id;
+};
+
+static struct inode *fuse_alloc_inode(struct super_block *sb)
+{
+ struct inode *inode;
+ struct fuse_inode *fi;
+
+ inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
+ if (!inode)
+ return NULL;
+
+ fi = get_fuse_inode(inode);
+ fi->i_time = jiffies - 1;
+ fi->nodeid = 0;
+
+ return inode;
+}
+
+static void fuse_destroy_inode(struct inode *inode)
+{
+ kmem_cache_free(fuse_inode_cachep, inode);
+}
+
+static void fuse_read_inode(struct inode *inode)
+{
+ /* No op */
+}
+
+static void fuse_clear_inode(struct inode *inode)
+{
+}
+
+void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
+{
+ if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
+ invalidate_inode_pages(inode->i_mapping);
+
+ inode->i_ino = attr->ino;
+ inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
+ inode->i_nlink = attr->nlink;
+ inode->i_uid = attr->uid;
+ inode->i_gid = attr->gid;
+ i_size_write(inode, attr->size);
+ inode->i_blksize = PAGE_CACHE_SIZE;
+ inode->i_blocks = attr->blocks;
+ inode->i_atime.tv_sec = attr->atime;
+ inode->i_atime.tv_nsec = attr->atimensec;
+ inode->i_mtime.tv_sec = attr->mtime;
+ inode->i_mtime.tv_nsec = attr->mtimensec;
+ inode->i_ctime.tv_sec = attr->ctime;
+ inode->i_ctime.tv_nsec = attr->ctimensec;
+}
+
+static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
+{
+ inode->i_mode = attr->mode & S_IFMT;
+ i_size_write(inode, attr->size);
+}
+
+static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
+{
+ unsigned long nodeid = *(unsigned long *) _nodeidp;
+ if (get_node_id(inode) == nodeid)
+ return 1;
+ else
+ return 0;
+}
+
+static int fuse_inode_set(struct inode *inode, void *_nodeidp)
+{
+ unsigned long nodeid = *(unsigned long *) _nodeidp;
+ get_fuse_inode(inode)->nodeid = nodeid;
+ return 0;
+}
+
+struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
+ int generation, struct fuse_attr *attr, int version)
+{
+ struct inode *inode;
+ struct fuse_conn *fc = get_fuse_conn_super(sb);
+ int retried = 0;
+
+ retry:
+ inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
+ if (!inode)
+ return NULL;
+
+ if ((inode->i_state & I_NEW)) {
+ inode->i_generation = generation;
+ inode->i_data.backing_dev_info = &fc->bdi;
+ fuse_init_inode(inode, attr);
+ unlock_new_inode(inode);
+ } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
+ BUG_ON(retried);
+ /* Inode has changed type, any I/O on the old should fail */
+ make_bad_inode(inode);
+ iput(inode);
+ retried = 1;
+ goto retry;
+ }
+
+ fuse_change_attributes(inode, attr);
+ inode->i_version = version;
+ return inode;
+}
+
+static void fuse_put_super(struct super_block *sb)
+{
+ struct fuse_conn *fc = get_fuse_conn_super(sb);
+
+ spin_lock(&fuse_lock);
+ mount_count --;
+ fc->sb = NULL;
+ fc->user_id = 0;
+ fuse_release_conn(fc);
+ *get_fuse_conn_super_p(sb) = NULL;
+ spin_unlock(&fuse_lock);
+}
+
+enum {
+ OPT_FD,
+ OPT_ROOTMODE,
+ OPT_USER_ID,
+ OPT_DEFAULT_PERMISSIONS,
+ OPT_ALLOW_OTHER,
+ OPT_ALLOW_ROOT,
+ OPT_KERNEL_CACHE,
+ OPT_ERR
+};
+
+static match_table_t tokens = {
+ {OPT_FD, "fd=%u"},
+ {OPT_ROOTMODE, "rootmode=%o"},
+ {OPT_USER_ID, "user_id=%u"},
+ {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
+ {OPT_ALLOW_OTHER, "allow_other"},
+ {OPT_ALLOW_ROOT, "allow_root"},
+ {OPT_KERNEL_CACHE, "kernel_cache"},
+ {OPT_ERR, NULL}
+};
+
+static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
+{
+ char *p;
+ memset(d, 0, sizeof(struct fuse_mount_data));
+ d->fd = -1;
+
+ while ((p = strsep(&opt, ",")) != NULL) {
+ int token;
+ int value;
+ 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;
+ break;
+
+ case OPT_ROOTMODE:
+ if (match_octal(&args[0], &value))
+ return 0;
+ d->rootmode = value;
+ break;
+
+ case OPT_USER_ID:
+ if (match_int(&args[0], &value))
+ return 0;
+ d->user_id = value;
+ break;
+
+ default:
+ return 0;
+ }
+ }
+ if (d->fd == -1)
+ return 0;
+
+ return 1;
+}
+
+static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
+{
+ struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
+
+ seq_printf(m, ",user_id=%u", fc->user_id);
+ return 0;
+}
+
+void fuse_release_conn(struct fuse_conn *fc)
+{
+ kfree(fc);
+}
+
+static struct fuse_conn *new_conn(void)
+{
+ struct fuse_conn *fc;
+
+ fc = kmalloc(sizeof(*fc), GFP_KERNEL);
+ if (fc != NULL) {
+ memset(fc, 0, sizeof(*fc));
+ fc->sb = NULL;
+ fc->user_id = 0;
+ fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
+ fc->bdi.unplug_io_fn = default_unplug_io_fn;
+ }
+ return fc;
+}
+
+static struct fuse_conn *get_conn(struct file *file, struct super_block *sb)
+{
+ struct fuse_conn *fc;
+
+ fc = new_conn();
+ if (fc == NULL)
+ return NULL;
+ spin_lock(&fuse_lock);
+ fc->sb = sb;
+ spin_unlock(&fuse_lock);
+ return fc;
+}
+
+static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
+{
+ struct fuse_attr attr;
+ memset(&attr, 0, sizeof(attr));
+
+ attr.mode = mode;
+ attr.ino = FUSE_ROOT_ID;
+ return fuse_iget(sb, 1, 0, &attr, 0);
+}
+
+static struct super_operations fuse_super_operations = {
+ .alloc_inode = fuse_alloc_inode,
+ .destroy_inode = fuse_destroy_inode,
+ .read_inode = fuse_read_inode,
+ .clear_inode = fuse_clear_inode,
+ .put_super = fuse_put_super,
+ .show_options = fuse_show_options,
+};
+
+static int inc_mount_count(void)
+{
+ int success = 0;
+ spin_lock(&fuse_lock);
+ mount_count ++;
+ if (mount_max == -1 || mount_count <= mount_max)
+ success = 1;
+ spin_unlock(&fuse_lock);
+ return success;
+}
+
+static int fuse_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct fuse_conn *fc;
+ struct inode *root;
+ struct fuse_mount_data d;
+ struct file *file;
+ int err;
+
+ if (!parse_fuse_opt((char *) data, &d))
+ return -EINVAL;
+
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_magic = FUSE_SUPER_MAGIC;
+ sb->s_op = &fuse_super_operations;
+ sb->s_maxbytes = MAX_LFS_FILESIZE;
+
+ file = fget(d.fd);
+ if (!file)
+ return -EINVAL;
+
+ fc = get_conn(file, sb);
+ fput(file);
+ if (fc == NULL)
+ return -EINVAL;
+
+ fc->user_id = d.user_id;
+
+ *get_fuse_conn_super_p(sb) = fc;
+
+ err = -ENFILE;
+ if (!inc_mount_count() && current->uid != 0)
+ goto err;
+
+ err = -ENOMEM;
+ root = get_root_inode(sb, d.rootmode);
+ if (root == NULL)
+ goto err;
+
+ sb->s_root = d_alloc_root(root);
+ if (!sb->s_root) {
+ iput(root);
+ goto err;
+ }
+ return 0;
+
+ err:
+ spin_lock(&fuse_lock);
+ mount_count --;
+ fc->sb = NULL;
+ fuse_release_conn(fc);
+ spin_unlock(&fuse_lock);
+ *get_fuse_conn_super_p(sb) = NULL;
+ return err;
+}
+
+static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name,
+ void *raw_data)
+{
+ return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super);
+}
+
+static struct file_system_type fuse_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "fuse",
+ .get_sb = fuse_get_sb,
+ .kill_sb = kill_anon_super,
+};
+
+static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
+ unsigned long flags)
+{
+ struct inode * inode = foo;
+
+ if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
+ SLAB_CTOR_CONSTRUCTOR)
+ inode_init_once(inode);
+}
+
+static int __init fuse_fs_init(void)
+{
+ int err;
+
+ err = register_filesystem(&fuse_fs_type);
+ if (err)
+ printk("fuse: failed to register filesystem\n");
+ else {
+ fuse_inode_cachep = kmem_cache_create("fuse_inode",
+ sizeof(struct fuse_inode),
+ 0, SLAB_HWCACHE_ALIGN,
+ fuse_inode_init_once, NULL);
+ if (!fuse_inode_cachep) {
+ unregister_filesystem(&fuse_fs_type);
+ err = -ENOMEM;
+ }
+ }
+
+ return err;
+}
+
+static void fuse_fs_cleanup(void)
+{
+ unregister_filesystem(&fuse_fs_type);
+ kmem_cache_destroy(fuse_inode_cachep);
+}
+
+static int __init fuse_init(void)
+{
+ int res;
+
+ printk("fuse init (API version %i.%i)\n",
+ FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
+
+ spin_lock_init(&fuse_lock);
+ res = fuse_fs_init();
+ if (res)
+ goto err;
+
+ return 0;
+
+ err:
+ return res;
+}
+
+static void __exit fuse_exit(void)
+{
+ printk(KERN_DEBUG "fuse exit\n");
+
+ fuse_fs_cleanup();
+}
+
+module_init(fuse_init);
+module_exit(fuse_exit);
diff -Nurp a/include/linux/fuse.h b/include/linux/fuse.h
--- a/include/linux/fuse.h 1970-01-01 01:00:00.000000000 +0100
+++ b/include/linux/fuse.h 2005-01-11 16:28:29.000000000 +0100
@@ -0,0 +1,38 @@
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+/* This file defines the kernel interface of FUSE */
+
+#include <asm/types.h>
+
+/** Version number of this interface */
+#define FUSE_KERNEL_VERSION 5
+
+/** Minor version number of this interface */
+#define FUSE_KERNEL_MINOR_VERSION 1
+
+/** The node ID of the root inode */
+#define FUSE_ROOT_ID 1
+
+struct fuse_attr {
+ __u64 ino;
+ __u64 size;
+ __u64 blocks;
+ __u64 atime;
+ __u64 mtime;
+ __u64 ctime;
+ __u32 atimensec;
+ __u32 mtimensec;
+ __u32 ctimensec;
+ __u32 mode;
+ __u32 nlink;
+ __u32 uid;
+ __u32 gid;
+ __u32 rdev;
+};
+
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH 2/11] FUSE - core
2005-01-11 16:25 [PATCH 2/11] FUSE - core Miklos Szeredi
@ 2005-01-12 22:36 ` Andrew Morton
2005-01-13 5:31 ` Miklos Szeredi
2005-01-14 13:55 ` Anton Altaparmakov
1 sibling, 1 reply; 11+ messages in thread
From: Andrew Morton @ 2005-01-12 22:36 UTC (permalink / raw)
To: Miklos Szeredi; +Cc: torvalds, linux-fsdevel, linux-kernel
Miklos Szeredi <miklos@szeredi.hu> wrote:
>
> +static int fuse_fill_super(struct super_block *sb, void *data, int silent)
> +{
> ...
> + if (!inc_mount_count() && current->uid != 0)
> + goto err;
The open-coded current->uid test needs to go. capable(CAP_SYS_ADMIN)?
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH 2/11] FUSE - core
2005-01-11 16:25 [PATCH 2/11] FUSE - core Miklos Szeredi
2005-01-12 22:36 ` Andrew Morton
@ 2005-01-14 13:55 ` Anton Altaparmakov
2005-01-14 14:07 ` Miklos Szeredi
1 sibling, 1 reply; 11+ messages in thread
From: Anton Altaparmakov @ 2005-01-14 13:55 UTC (permalink / raw)
To: Miklos Szeredi; +Cc: akpm, torvalds, linux-fsdevel, linux-kernel
Comments in code...
On Tue, 11 Jan 2005, Miklos Szeredi wrote:
> This patch adds FUSE core.
>
> This contains the following files:
>
> o inode.c
> - superblock operations (alloc_inode, destroy_inode, read_inode,
> clear_inode, put_super, show_options)
> - registers FUSE filesystem
>
> o fuse_i.h
> - private header file
>
> Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
> diff -Nurp a/fs/fuse/Makefile b/fs/fuse/Makefile
> --- a/fs/fuse/Makefile 1970-01-01 01:00:00.000000000 +0100
> +++ b/fs/fuse/Makefile 2005-01-11 16:28:29.000000000 +0100
> @@ -0,0 +1,7 @@
> +#
> +# Makefile for the FUSE filesystem.
> +#
> +
> +obj-$(CONFIG_FUSE_FS) += fuse.o
> +
> +fuse-objs := inode.o
> diff -Nurp a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
> --- a/fs/fuse/fuse_i.h 1970-01-01 01:00:00.000000000 +0100
> +++ b/fs/fuse/fuse_i.h 2005-01-11 16:28:29.000000000 +0100
> @@ -0,0 +1,89 @@
> +/*
> + FUSE: Filesystem in Userspace
> + Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
> +
> + This program can be distributed under the terms of the GNU GPL.
> + See the file COPYING.
> +*/
> +
> +#include <linux/fuse.h>
> +#include <linux/fs.h>
> +#include <linux/wait.h>
> +#include <linux/list.h>
> +#include <linux/spinlock.h>
> +#include <linux/mm.h>
> +#include <linux/backing-dev.h>
> +#include <asm/semaphore.h>
> +
> +/** FUSE inode */
> +struct fuse_inode {
> + /** Inode data */
> + struct inode inode;
> +
> + /** Unique ID, which identifies the inode between userspace
> + * and kernel */
> + u64 nodeid;
> +
> + /** Time in jiffies until the file attributes are valid */
> + unsigned long i_time;
> +};
> +
> +/**
> + * A Fuse connection.
> + *
> + * This structure is created, when the filesystem is mounted, and is
> + * destroyed, when the client device is closed and the filesystem is
> + * unmounted.
> + */
> +struct fuse_conn {
> + /** The superblock of the mounted filesystem */
> + struct super_block *sb;
> +
> + /** The user id for this mount */
> + uid_t user_id;
> +
> + /** Backing dev info */
> + struct backing_dev_info bdi;
> +};
> +
> +static inline struct fuse_conn **get_fuse_conn_super_p(struct super_block *sb)
> +{
> + return (struct fuse_conn **) &sb->s_fs_info;
> +}
> +
> +static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
> +{
> + return *get_fuse_conn_super_p(sb);
> +}
> +
> +static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
> +{
> + return get_fuse_conn_super(inode->i_sb);
> +}
> +
> +static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
> +{
> + return container_of(inode, struct fuse_inode, inode);
> +}
> +
> +static inline u64 get_node_id(struct inode *inode)
> +{
> + return get_fuse_inode(inode)->nodeid;
> +}
> +
> +/**
> + * This is the single global spinlock which protects FUSE's structures
> + *
> + * The following data is protected by this lock:
> + *
> + * - the s_fs_info field of the super block
> + * - the sb (super_block) field in fuse_conn
> + */
> +extern spinlock_t fuse_lock;
> +
> +/**
> + * Check if the connection can be released, and if yes, then free the
> + * connection structure
> + */
> +void fuse_release_conn(struct fuse_conn *fc);
> +
> diff -Nurp a/fs/fuse/inode.c b/fs/fuse/inode.c
> --- a/fs/fuse/inode.c 1970-01-01 01:00:00.000000000 +0100
> +++ b/fs/fuse/inode.c 2005-01-11 16:28:29.000000000 +0100
> @@ -0,0 +1,428 @@
> +/*
> + FUSE: Filesystem in Userspace
> + Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
> +
> + This program can be distributed under the terms of the GNU GPL.
> + See the file COPYING.
> +*/
> +
> +#include "fuse_i.h"
> +
> +#include <linux/pagemap.h>
> +#include <linux/slab.h>
> +#include <linux/file.h>
> +#include <linux/mount.h>
> +#include <linux/seq_file.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/parser.h>
> +#include <linux/statfs.h>
> +
> +MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
> +MODULE_DESCRIPTION("Filesystem in Userspace");
> +MODULE_LICENSE("GPL");
> +
> +spinlock_t fuse_lock;
> +static kmem_cache_t *fuse_inode_cachep;
> +static int mount_count;
> +
> +static int mount_max = 1000;
> +module_param(mount_max, int, 0644);
> +MODULE_PARM_DESC(mount_max, "Maximum number of FUSE mounts allowed, if -1 then unlimited (default: 1000)");
> +
> +#define FUSE_SUPER_MAGIC 0x65735546
> +
> +struct fuse_mount_data {
> + int fd;
> + unsigned rootmode;
> + unsigned user_id;
> +};
> +
> +static struct inode *fuse_alloc_inode(struct super_block *sb)
> +{
> + struct inode *inode;
> + struct fuse_inode *fi;
> +
> + inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
This should probably be SLAB_NOFS as FUSE is a file system so you don't
want allocations to go off submitting i/o to your file system. Much
better to be safe and always use the _NOFS versions in you kernel fs code.
> + if (!inode)
> + return NULL;
> +
> + fi = get_fuse_inode(inode);
> + fi->i_time = jiffies - 1;
> + fi->nodeid = 0;
> +
> + return inode;
> +}
> +
> +static void fuse_destroy_inode(struct inode *inode)
> +{
> + kmem_cache_free(fuse_inode_cachep, inode);
> +}
> +
> +static void fuse_read_inode(struct inode *inode)
> +{
> + /* No op */
> +}
> +
> +static void fuse_clear_inode(struct inode *inode)
> +{
> +}
> +
> +void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
> +{
> + if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
> + invalidate_inode_pages(inode->i_mapping);
> +
> + inode->i_ino = attr->ino;
> + inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
> + inode->i_nlink = attr->nlink;
> + inode->i_uid = attr->uid;
> + inode->i_gid = attr->gid;
> + i_size_write(inode, attr->size);
> + inode->i_blksize = PAGE_CACHE_SIZE;
> + inode->i_blocks = attr->blocks;
> + inode->i_atime.tv_sec = attr->atime;
> + inode->i_atime.tv_nsec = attr->atimensec;
> + inode->i_mtime.tv_sec = attr->mtime;
> + inode->i_mtime.tv_nsec = attr->mtimensec;
> + inode->i_ctime.tv_sec = attr->ctime;
> + inode->i_ctime.tv_nsec = attr->ctimensec;
> +}
> +
> +static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
> +{
> + inode->i_mode = attr->mode & S_IFMT;
> + i_size_write(inode, attr->size);
> +}
> +
> +static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
> +{
> + unsigned long nodeid = *(unsigned long *) _nodeidp;
> + if (get_node_id(inode) == nodeid)
> + return 1;
> + else
> + return 0;
> +}
> +
> +static int fuse_inode_set(struct inode *inode, void *_nodeidp)
> +{
> + unsigned long nodeid = *(unsigned long *) _nodeidp;
> + get_fuse_inode(inode)->nodeid = nodeid;
> + return 0;
> +}
> +
> +struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
> + int generation, struct fuse_attr *attr, int version)
> +{
> + struct inode *inode;
> + struct fuse_conn *fc = get_fuse_conn_super(sb);
> + int retried = 0;
> +
> + retry:
> + inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
> + if (!inode)
> + return NULL;
> +
> + if ((inode->i_state & I_NEW)) {
> + inode->i_generation = generation;
> + inode->i_data.backing_dev_info = &fc->bdi;
> + fuse_init_inode(inode, attr);
> + unlock_new_inode(inode);
> + } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
> + BUG_ON(retried);
> + /* Inode has changed type, any I/O on the old should fail */
> + make_bad_inode(inode);
> + iput(inode);
> + retried = 1;
> + goto retry;
> + }
> +
> + fuse_change_attributes(inode, attr);
> + inode->i_version = version;
> + return inode;
> +}
> +
> +static void fuse_put_super(struct super_block *sb)
> +{
> + struct fuse_conn *fc = get_fuse_conn_super(sb);
> +
> + spin_lock(&fuse_lock);
> + mount_count --;
> + fc->sb = NULL;
> + fc->user_id = 0;
> + fuse_release_conn(fc);
> + *get_fuse_conn_super_p(sb) = NULL;
> + spin_unlock(&fuse_lock);
> +}
> +
> +enum {
> + OPT_FD,
> + OPT_ROOTMODE,
> + OPT_USER_ID,
> + OPT_DEFAULT_PERMISSIONS,
> + OPT_ALLOW_OTHER,
> + OPT_ALLOW_ROOT,
> + OPT_KERNEL_CACHE,
> + OPT_ERR
> +};
> +
> +static match_table_t tokens = {
> + {OPT_FD, "fd=%u"},
> + {OPT_ROOTMODE, "rootmode=%o"},
> + {OPT_USER_ID, "user_id=%u"},
> + {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
> + {OPT_ALLOW_OTHER, "allow_other"},
> + {OPT_ALLOW_ROOT, "allow_root"},
> + {OPT_KERNEL_CACHE, "kernel_cache"},
> + {OPT_ERR, NULL}
> +};
> +
> +static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
> +{
> + char *p;
> + memset(d, 0, sizeof(struct fuse_mount_data));
> + d->fd = -1;
> +
> + while ((p = strsep(&opt, ",")) != NULL) {
> + int token;
> + int value;
> + 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;
> + break;
> +
> + case OPT_ROOTMODE:
> + if (match_octal(&args[0], &value))
> + return 0;
> + d->rootmode = value;
> + break;
> +
> + case OPT_USER_ID:
> + if (match_int(&args[0], &value))
> + return 0;
> + d->user_id = value;
> + break;
> +
> + default:
> + return 0;
> + }
> + }
> + if (d->fd == -1)
> + return 0;
> +
> + return 1;
> +}
> +
> +static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
> +{
> + struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
> +
> + seq_printf(m, ",user_id=%u", fc->user_id);
> + return 0;
> +}
> +
> +void fuse_release_conn(struct fuse_conn *fc)
> +{
> + kfree(fc);
> +}
> +
> +static struct fuse_conn *new_conn(void)
> +{
> + struct fuse_conn *fc;
> +
> + fc = kmalloc(sizeof(*fc), GFP_KERNEL);
Same comment as before: GFP_NOFS is safer.
> + if (fc != NULL) {
> + memset(fc, 0, sizeof(*fc));
> + fc->sb = NULL;
> + fc->user_id = 0;
> + fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
> + fc->bdi.unplug_io_fn = default_unplug_io_fn;
> + }
> + return fc;
> +}
> +
> +static struct fuse_conn *get_conn(struct file *file, struct super_block *sb)
> +{
> + struct fuse_conn *fc;
> +
> + fc = new_conn();
> + if (fc == NULL)
> + return NULL;
> + spin_lock(&fuse_lock);
> + fc->sb = sb;
> + spin_unlock(&fuse_lock);
> + return fc;
> +}
> +
> +static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
> +{
> + struct fuse_attr attr;
> + memset(&attr, 0, sizeof(attr));
> +
> + attr.mode = mode;
> + attr.ino = FUSE_ROOT_ID;
> + return fuse_iget(sb, 1, 0, &attr, 0);
> +}
> +
> +static struct super_operations fuse_super_operations = {
> + .alloc_inode = fuse_alloc_inode,
> + .destroy_inode = fuse_destroy_inode,
> + .read_inode = fuse_read_inode,
> + .clear_inode = fuse_clear_inode,
> + .put_super = fuse_put_super,
> + .show_options = fuse_show_options,
> +};
> +
> +static int inc_mount_count(void)
> +{
> + int success = 0;
> + spin_lock(&fuse_lock);
> + mount_count ++;
> + if (mount_max == -1 || mount_count <= mount_max)
> + success = 1;
> + spin_unlock(&fuse_lock);
> + return success;
> +}
> +
> +static int fuse_fill_super(struct super_block *sb, void *data, int silent)
> +{
> + struct fuse_conn *fc;
> + struct inode *root;
> + struct fuse_mount_data d;
> + struct file *file;
> + int err;
> +
> + if (!parse_fuse_opt((char *) data, &d))
> + return -EINVAL;
> +
> + sb->s_blocksize = PAGE_CACHE_SIZE;
> + sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
> + sb->s_magic = FUSE_SUPER_MAGIC;
> + sb->s_op = &fuse_super_operations;
> + sb->s_maxbytes = MAX_LFS_FILESIZE;
> +
> + file = fget(d.fd);
> + if (!file)
> + return -EINVAL;
> +
> + fc = get_conn(file, sb);
> + fput(file);
> + if (fc == NULL)
> + return -EINVAL;
> +
> + fc->user_id = d.user_id;
> +
> + *get_fuse_conn_super_p(sb) = fc;
> +
> + err = -ENFILE;
> + if (!inc_mount_count() && current->uid != 0)
> + goto err;
> +
> + err = -ENOMEM;
> + root = get_root_inode(sb, d.rootmode);
> + if (root == NULL)
> + goto err;
> +
> + sb->s_root = d_alloc_root(root);
> + if (!sb->s_root) {
> + iput(root);
> + goto err;
> + }
> + return 0;
> +
> + err:
> + spin_lock(&fuse_lock);
> + mount_count --;
> + fc->sb = NULL;
> + fuse_release_conn(fc);
> + spin_unlock(&fuse_lock);
> + *get_fuse_conn_super_p(sb) = NULL;
> + return err;
> +}
> +
> +static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
> + int flags, const char *dev_name,
> + void *raw_data)
> +{
> + return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super);
> +}
> +
> +static struct file_system_type fuse_fs_type = {
> + .owner = THIS_MODULE,
> + .name = "fuse",
> + .get_sb = fuse_get_sb,
> + .kill_sb = kill_anon_super,
> +};
> +
> +static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
> + unsigned long flags)
> +{
> + struct inode * inode = foo;
> +
> + if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
> + SLAB_CTOR_CONSTRUCTOR)
> + inode_init_once(inode);
> +}
> +
> +static int __init fuse_fs_init(void)
> +{
> + int err;
> +
> + err = register_filesystem(&fuse_fs_type);
> + if (err)
> + printk("fuse: failed to register filesystem\n");
> + else {
> + fuse_inode_cachep = kmem_cache_create("fuse_inode",
> + sizeof(struct fuse_inode),
> + 0, SLAB_HWCACHE_ALIGN,
> + fuse_inode_init_once, NULL);
> + if (!fuse_inode_cachep) {
> + unregister_filesystem(&fuse_fs_type);
> + err = -ENOMEM;
> + }
> + }
> +
> + return err;
> +}
> +
> +static void fuse_fs_cleanup(void)
> +{
> + unregister_filesystem(&fuse_fs_type);
> + kmem_cache_destroy(fuse_inode_cachep);
> +}
> +
> +static int __init fuse_init(void)
> +{
> + int res;
> +
> + printk("fuse init (API version %i.%i)\n",
> + FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
> +
> + spin_lock_init(&fuse_lock);
> + res = fuse_fs_init();
> + if (res)
> + goto err;
> +
> + return 0;
> +
> + err:
> + return res;
> +}
> +
> +static void __exit fuse_exit(void)
> +{
> + printk(KERN_DEBUG "fuse exit\n");
> +
> + fuse_fs_cleanup();
> +}
> +
> +module_init(fuse_init);
> +module_exit(fuse_exit);
> diff -Nurp a/include/linux/fuse.h b/include/linux/fuse.h
> --- a/include/linux/fuse.h 1970-01-01 01:00:00.000000000 +0100
> +++ b/include/linux/fuse.h 2005-01-11 16:28:29.000000000 +0100
> @@ -0,0 +1,38 @@
> +/*
> + FUSE: Filesystem in Userspace
> + Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
> +
> + This program can be distributed under the terms of the GNU GPL.
> + See the file COPYING.
> +*/
> +
> +/* This file defines the kernel interface of FUSE */
> +
> +#include <asm/types.h>
> +
> +/** Version number of this interface */
> +#define FUSE_KERNEL_VERSION 5
> +
> +/** Minor version number of this interface */
> +#define FUSE_KERNEL_MINOR_VERSION 1
> +
> +/** The node ID of the root inode */
> +#define FUSE_ROOT_ID 1
> +
> +struct fuse_attr {
> + __u64 ino;
> + __u64 size;
> + __u64 blocks;
> + __u64 atime;
> + __u64 mtime;
> + __u64 ctime;
> + __u32 atimensec;
> + __u32 mtimensec;
> + __u32 ctimensec;
> + __u32 mode;
> + __u32 nlink;
> + __u32 uid;
> + __u32 gid;
> + __u32 rdev;
> +};
> +
Best regards,
Anton
--
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net
WWW: http://linux-ntfs.sf.net/ & http://www-stu.christs.cam.ac.uk/~aia21/
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH 2/11] FUSE - core
2005-01-14 13:55 ` Anton Altaparmakov
@ 2005-01-14 14:07 ` Miklos Szeredi
2005-01-14 14:14 ` Anton Altaparmakov
0 siblings, 1 reply; 11+ messages in thread
From: Miklos Szeredi @ 2005-01-14 14:07 UTC (permalink / raw)
To: aia21; +Cc: akpm, torvalds, linux-fsdevel, linux-kernel
> > +static struct inode *fuse_alloc_inode(struct super_block *sb)
> > +{
> > + struct inode *inode;
> > + struct fuse_inode *fi;
> > +
> > + inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
>
> This should probably be SLAB_NOFS as FUSE is a file system so you don't
> want allocations to go off submitting i/o to your file system. Much
> better to be safe and always use the _NOFS versions in you kernel fs code.
Well, I don't think it matters in this case, since inode allocation is
not part of processing I/O, so no deadlock is possible. See also
alloc_inode() in fs/inode.c which also uses SLAB_KERNEL.
> > +static struct fuse_conn *new_conn(void)
> > +{
> > + struct fuse_conn *fc;
> > +
> > + fc = kmalloc(sizeof(*fc), GFP_KERNEL);
>
> Same comment as before: GFP_NOFS is safer.
Same reason as above.
In actual fact the whole GFP_NOFS argument doesn't apply to FUSE
_at_all_, since dirty pages are never allowed. Which is because
userspace can't easily be taught about GFP_NOFS allocations, and
otherwise could deadlock on page writeback.
Thanks,
Miklos
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH 2/11] FUSE - core
2005-01-14 14:07 ` Miklos Szeredi
@ 2005-01-14 14:14 ` Anton Altaparmakov
2005-01-14 14:32 ` Miklos Szeredi
0 siblings, 1 reply; 11+ messages in thread
From: Anton Altaparmakov @ 2005-01-14 14:14 UTC (permalink / raw)
To: Miklos Szeredi; +Cc: akpm, torvalds, linux-fsdevel, linux-kernel
On Fri, 14 Jan 2005, Miklos Szeredi wrote:
> > > +static struct inode *fuse_alloc_inode(struct super_block *sb)
> > > +{
> > > + struct inode *inode;
> > > + struct fuse_inode *fi;
> > > +
> > > + inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
> >
> > This should probably be SLAB_NOFS as FUSE is a file system so you don't
> > want allocations to go off submitting i/o to your file system. Much
> > better to be safe and always use the _NOFS versions in you kernel fs code.
>
> Well, I don't think it matters in this case, since inode allocation is
> not part of processing I/O, so no deadlock is possible. See also
> alloc_inode() in fs/inode.c which also uses SLAB_KERNEL.
That may well be possible. I prefer to take a more cautious approach and
only use _NOFS variants within NTFS, whether it is strictly necessary or
not. That way I never need to worry as to whether a deadlock is or isn't
possible. The problem simply goes away...
[snip]
> In actual fact the whole GFP_NOFS argument doesn't apply to FUSE
> _at_all_, since dirty pages are never allowed. Which is because
> userspace can't easily be taught about GFP_NOFS allocations, and
> otherwise could deadlock on page writeback.
Yes, I remember the thread about the deadlock on page writeback.
I prefer the _NOFS regardless (and others will probably disagree) because
it also means that if a machine is seriously running out of memory the fs
will give up with -ENOMEM much more readily with _NOFS rather than
increasing the memory pressure even further. As I said, others probably
disagree with me...
Best regards,
Anton
--
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net
WWW: http://linux-ntfs.sf.net/ & http://www-stu.christs.cam.ac.uk/~aia21/
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH 2/11] FUSE - core
2005-01-14 14:14 ` Anton Altaparmakov
@ 2005-01-14 14:32 ` Miklos Szeredi
0 siblings, 0 replies; 11+ messages in thread
From: Miklos Szeredi @ 2005-01-14 14:32 UTC (permalink / raw)
To: aia21; +Cc: akpm, torvalds, linux-fsdevel, linux-kernel
> I prefer the _NOFS regardless (and others will probably disagree) because
> it also means that if a machine is seriously running out of memory the fs
> will give up with -ENOMEM much more readily with _NOFS rather than
> increasing the memory pressure even further. As I said, others probably
> disagree with me...
Then you are suggesting to add __GFP_NORETRY, to all my allocations.
That's may well be a valid argument, if we want to treat userspace
filesystems less critical, than other things.
Adding _NOFS in the case where no deadlock is possible makes things
worse not better, since you are limiting the allocation from
performing I/O. It's clearly a losing situation.
Thanks,
Miklos
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 2/11] FUSE - core
@ 2005-01-10 18:58 Miklos Szeredi
2005-01-10 21:40 ` Mike Waychison
2005-02-14 22:43 ` Faraz Ahmed
0 siblings, 2 replies; 11+ messages in thread
From: Miklos Szeredi @ 2005-01-10 18:58 UTC (permalink / raw)
To: akpm, torvalds; +Cc: linux-fsdevel, linux-kernel
This patch adds FUSE core.
This contains the following files:
o inode.c
- superblock operations (alloc_inode, destroy_inode, read_inode,
clear_inode, put_super, show_options)
- registers FUSE filesystem
o fuse_i.h
- private header file
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
diff -Nurp a/fs/fuse/Makefile b/fs/fuse/Makefile
--- a/fs/fuse/Makefile 1970-01-01 01:00:00.000000000 +0100
+++ b/fs/fuse/Makefile 2005-01-10 19:28:38.000000000 +0100
@@ -0,0 +1,7 @@
+#
+# Makefile for the FUSE filesystem.
+#
+
+obj-$(CONFIG_FUSE) += fuse.o
+
+fuse-objs := inode.o
diff -Nurp a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
--- a/fs/fuse/fuse_i.h 1970-01-01 01:00:00.000000000 +0100
+++ b/fs/fuse/fuse_i.h 2005-01-10 19:28:38.000000000 +0100
@@ -0,0 +1,90 @@
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+#include <linux/fuse.h>
+#include <linux/fs.h>
+#include <linux/wait.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/backing-dev.h>
+#include <asm/semaphore.h>
+
+/** FUSE specific inode data */
+struct fuse_inode {
+ /** Unique ID, which identifies the inode between userspace
+ * and kernel */
+ u64 nodeid;
+
+ /** Time in jiffies until the file attributes are valid */
+ unsigned long i_time;
+};
+
+/**
+ * A Fuse connection.
+ *
+ * This structure is created, when the filesystem is mounted, and is
+ * destroyed, when the client device is closed and the filesystem is
+ * unmounted.
+ */
+struct fuse_conn {
+ /** The superblock of the mounted filesystem */
+ struct super_block *sb;
+
+ /** The user id for this mount */
+ uid_t user_id;
+
+ /** Backing dev info */
+ struct backing_dev_info bdi;
+};
+
+static inline struct fuse_conn **get_fuse_conn_super_p(struct super_block *sb)
+{
+ return (struct fuse_conn **) &sb->s_fs_info;
+}
+
+static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
+{
+ return *get_fuse_conn_super_p(sb);
+}
+
+static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
+{
+ return get_fuse_conn_super(inode->i_sb);
+}
+
+static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
+{
+ return (struct fuse_inode *) (&inode[1]);
+}
+
+static inline u64 get_node_id(struct inode *inode)
+{
+ return get_fuse_inode(inode)->nodeid;
+}
+
+/**
+ * This is the single global spinlock which protects FUSE's structures
+ *
+ * The following data is protected by this lock:
+ *
+ * - the private_data field of the device file
+ * - the s_fs_info field of the super block
+ * - unused_list, pending, processing lists in fuse_conn
+ * - the unique request ID counter reqctr in fuse_conn
+ * - the sb (super_block) field in fuse_conn
+ * - the file (device file) field in fuse_conn
+ */
+extern spinlock_t fuse_lock;
+
+/**
+ * Check if the connection can be released, and if yes, then free the
+ * connection structure
+ */
+void fuse_release_conn(struct fuse_conn *fc);
+
diff -Nurp a/fs/fuse/inode.c b/fs/fuse/inode.c
--- a/fs/fuse/inode.c 1970-01-01 01:00:00.000000000 +0100
+++ b/fs/fuse/inode.c 2005-01-10 19:28:38.000000000 +0100
@@ -0,0 +1,427 @@
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+#include "fuse_i.h"
+
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/mount.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/parser.h>
+#include <linux/statfs.h>
+
+MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
+MODULE_DESCRIPTION("Filesystem in Userspace");
+MODULE_LICENSE("GPL");
+
+spinlock_t fuse_lock;
+static kmem_cache_t *fuse_inode_cachep;
+static int mount_count;
+
+static int mount_max = 1000;
+module_param(mount_max, int, 0644);
+MODULE_PARM_DESC(mount_max, "Maximum number of FUSE mounts allowed, if -1 then unlimited (default: 1000)");
+
+#define FUSE_SUPER_MAGIC 0x65735546
+
+struct fuse_mount_data {
+ int fd;
+ unsigned rootmode;
+ unsigned user_id;
+};
+
+static struct inode *fuse_alloc_inode(struct super_block *sb)
+{
+ struct inode *inode;
+ struct fuse_inode *fi;
+
+ inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
+ if (!inode)
+ return NULL;
+
+ fi = get_fuse_inode(inode);
+ memset(fi, 0, sizeof(*fi));
+
+ return inode;
+}
+
+static void fuse_destroy_inode(struct inode *inode)
+{
+ kmem_cache_free(fuse_inode_cachep, inode);
+}
+
+static void fuse_read_inode(struct inode *inode)
+{
+ /* No op */
+}
+
+static void fuse_clear_inode(struct inode *inode)
+{
+}
+
+void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
+{
+ if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
+ invalidate_inode_pages(inode->i_mapping);
+
+ inode->i_ino = attr->ino;
+ inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
+ inode->i_nlink = attr->nlink;
+ inode->i_uid = attr->uid;
+ inode->i_gid = attr->gid;
+ i_size_write(inode, attr->size);
+ inode->i_blksize = PAGE_CACHE_SIZE;
+ inode->i_blocks = attr->blocks;
+ inode->i_atime.tv_sec = attr->atime;
+ inode->i_atime.tv_nsec = attr->atimensec;
+ inode->i_mtime.tv_sec = attr->mtime;
+ inode->i_mtime.tv_nsec = attr->mtimensec;
+ inode->i_ctime.tv_sec = attr->ctime;
+ inode->i_ctime.tv_nsec = attr->ctimensec;
+}
+
+static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
+{
+ inode->i_mode = attr->mode & S_IFMT;
+ i_size_write(inode, attr->size);
+}
+
+static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
+{
+ unsigned long nodeid = *(unsigned long *) _nodeidp;
+ if (get_node_id(inode) == nodeid)
+ return 1;
+ else
+ return 0;
+}
+
+static int fuse_inode_set(struct inode *inode, void *_nodeidp)
+{
+ unsigned long nodeid = *(unsigned long *) _nodeidp;
+ get_fuse_inode(inode)->nodeid = nodeid;
+ return 0;
+}
+
+struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
+ int generation, struct fuse_attr *attr, int version)
+{
+ struct inode *inode;
+ struct fuse_conn *fc = get_fuse_conn_super(sb);
+ int retried = 0;
+
+ retry:
+ inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
+ if (!inode)
+ return NULL;
+
+ if ((inode->i_state & I_NEW)) {
+ inode->i_generation = generation;
+ inode->i_data.backing_dev_info = &fc->bdi;
+ fuse_init_inode(inode, attr);
+ unlock_new_inode(inode);
+ } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
+ BUG_ON(retried);
+ /* Inode has changed type, any I/O on the old should fail */
+ make_bad_inode(inode);
+ iput(inode);
+ retried = 1;
+ goto retry;
+ }
+
+ fuse_change_attributes(inode, attr);
+ inode->i_version = version;
+ return inode;
+}
+
+static void fuse_put_super(struct super_block *sb)
+{
+ struct fuse_conn *fc = get_fuse_conn_super(sb);
+
+ spin_lock(&fuse_lock);
+ mount_count --;
+ fc->sb = NULL;
+ fc->user_id = 0;
+ fuse_release_conn(fc);
+ *get_fuse_conn_super_p(sb) = NULL;
+ spin_unlock(&fuse_lock);
+}
+
+enum {
+ OPT_FD,
+ OPT_ROOTMODE,
+ OPT_USER_ID,
+ OPT_DEFAULT_PERMISSIONS,
+ OPT_ALLOW_OTHER,
+ OPT_ALLOW_ROOT,
+ OPT_KERNEL_CACHE,
+ OPT_ERR
+};
+
+static match_table_t tokens = {
+ {OPT_FD, "fd=%u"},
+ {OPT_ROOTMODE, "rootmode=%o"},
+ {OPT_USER_ID, "user_id=%u"},
+ {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
+ {OPT_ALLOW_OTHER, "allow_other"},
+ {OPT_ALLOW_ROOT, "allow_root"},
+ {OPT_KERNEL_CACHE, "kernel_cache"},
+ {OPT_ERR, NULL}
+};
+
+static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
+{
+ char *p;
+ memset(d, 0, sizeof(struct fuse_mount_data));
+ d->fd = -1;
+
+ while ((p = strsep(&opt, ",")) != NULL) {
+ int token;
+ int value;
+ 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;
+ break;
+
+ case OPT_ROOTMODE:
+ if (match_octal(&args[0], &value))
+ return 0;
+ d->rootmode = value;
+ break;
+
+ case OPT_USER_ID:
+ if (match_int(&args[0], &value))
+ return 0;
+ d->user_id = value;
+ break;
+
+ default:
+ return 0;
+ }
+ }
+ if (d->fd == -1)
+ return 0;
+
+ return 1;
+}
+
+static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
+{
+ struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
+
+ seq_printf(m, ",user_id=%u", fc->user_id);
+ return 0;
+}
+
+void fuse_release_conn(struct fuse_conn *fc)
+{
+ kfree(fc);
+}
+
+static struct fuse_conn *new_conn(void)
+{
+ struct fuse_conn *fc;
+
+ fc = kmalloc(sizeof(*fc), GFP_KERNEL);
+ if (fc != NULL) {
+ memset(fc, 0, sizeof(*fc));
+ fc->sb = NULL;
+ fc->user_id = 0;
+ fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
+ fc->bdi.unplug_io_fn = default_unplug_io_fn;
+ }
+ return fc;
+}
+
+static struct fuse_conn *get_conn(struct file *file, struct super_block *sb)
+{
+ struct fuse_conn *fc;
+
+ fc = new_conn();
+ if (fc == NULL)
+ return NULL;
+ spin_lock(&fuse_lock);
+ fc->sb = sb;
+ spin_unlock(&fuse_lock);
+ return fc;
+}
+
+static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
+{
+ struct fuse_attr attr;
+ memset(&attr, 0, sizeof(attr));
+
+ attr.mode = mode;
+ attr.ino = FUSE_ROOT_ID;
+ return fuse_iget(sb, 1, 0, &attr, 0);
+}
+
+static struct super_operations fuse_super_operations = {
+ .alloc_inode = fuse_alloc_inode,
+ .destroy_inode = fuse_destroy_inode,
+ .read_inode = fuse_read_inode,
+ .clear_inode = fuse_clear_inode,
+ .put_super = fuse_put_super,
+ .show_options = fuse_show_options,
+};
+
+static int inc_mount_count(void)
+{
+ int success = 0;
+ spin_lock(&fuse_lock);
+ mount_count ++;
+ if (mount_max == -1 || mount_count <= mount_max)
+ success = 1;
+ spin_unlock(&fuse_lock);
+ return success;
+}
+
+static int fuse_read_super(struct super_block *sb, void *data, int silent)
+{
+ struct fuse_conn *fc;
+ struct inode *root;
+ struct fuse_mount_data d;
+ struct file *file;
+ int err;
+
+ if (!parse_fuse_opt((char *) data, &d))
+ return -EINVAL;
+
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_magic = FUSE_SUPER_MAGIC;
+ sb->s_op = &fuse_super_operations;
+ sb->s_maxbytes = MAX_LFS_FILESIZE;
+
+ file = fget(d.fd);
+ if (!file)
+ return -EINVAL;
+
+ fc = get_conn(file, sb);
+ fput(file);
+ if (fc == NULL)
+ return -EINVAL;
+
+ fc->user_id = d.user_id;
+
+ *get_fuse_conn_super_p(sb) = fc;
+
+ err = -ENFILE;
+ if (!inc_mount_count() && current->uid != 0)
+ goto err;
+
+ err = -ENOMEM;
+ root = get_root_inode(sb, d.rootmode);
+ if (root == NULL)
+ goto err;
+
+ sb->s_root = d_alloc_root(root);
+ if (!sb->s_root) {
+ iput(root);
+ goto err;
+ }
+ return 0;
+
+ err:
+ spin_lock(&fuse_lock);
+ mount_count --;
+ fc->sb = NULL;
+ fuse_release_conn(fc);
+ spin_unlock(&fuse_lock);
+ *get_fuse_conn_super_p(sb) = NULL;
+ return err;
+}
+
+static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name,
+ void *raw_data)
+{
+ return get_sb_nodev(fs_type, flags, raw_data, fuse_read_super);
+}
+
+static struct file_system_type fuse_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "fuse",
+ .get_sb = fuse_get_sb,
+ .kill_sb = kill_anon_super,
+};
+
+static void fuse_inode_init_once(void * foo, kmem_cache_t * cachep,
+ unsigned long flags)
+{
+ struct inode * inode = foo;
+
+ if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
+ SLAB_CTOR_CONSTRUCTOR)
+ inode_init_once(inode);
+}
+
+static int __init fuse_fs_init(void)
+{
+ int err;
+
+ err = register_filesystem(&fuse_fs_type);
+ if (err)
+ printk("fuse: failed to register filesystem\n");
+ else {
+ fuse_inode_cachep = kmem_cache_create("fuse_inode",
+ sizeof(struct inode) + sizeof(struct fuse_inode) ,
+ 0, SLAB_HWCACHE_ALIGN,
+ fuse_inode_init_once, NULL);
+ if (!fuse_inode_cachep) {
+ unregister_filesystem(&fuse_fs_type);
+ err = -ENOMEM;
+ }
+ }
+
+ return err;
+}
+
+static void fuse_fs_cleanup(void)
+{
+ unregister_filesystem(&fuse_fs_type);
+ kmem_cache_destroy(fuse_inode_cachep);
+}
+
+int __init fuse_init(void)
+{
+ int res;
+
+ printk("fuse init (API version %i.%i)\n",
+ FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
+
+ spin_lock_init(&fuse_lock);
+ res = fuse_fs_init();
+ if (res)
+ goto err;
+
+ return 0;
+
+ err:
+ return res;
+}
+
+void __exit fuse_exit(void)
+{
+ printk(KERN_DEBUG "fuse exit\n");
+
+ fuse_fs_cleanup();
+}
+
+module_init(fuse_init);
+module_exit(fuse_exit);
diff -Nurp a/include/linux/fuse.h b/include/linux/fuse.h
--- a/include/linux/fuse.h 1970-01-01 01:00:00.000000000 +0100
+++ b/include/linux/fuse.h 2005-01-10 19:28:38.000000000 +0100
@@ -0,0 +1,38 @@
+/*
+ FUSE: Filesystem in Userspace
+ Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
+
+ This program can be distributed under the terms of the GNU GPL.
+ See the file COPYING.
+*/
+
+/* This file defines the kernel interface of FUSE */
+
+#include <asm/types.h>
+
+/** Version number of this interface */
+#define FUSE_KERNEL_VERSION 5
+
+/** Minor version number of this interface */
+#define FUSE_KERNEL_MINOR_VERSION 1
+
+/** The node ID of the root inode */
+#define FUSE_ROOT_ID 1
+
+struct fuse_attr {
+ __u64 ino;
+ __u64 size;
+ __u64 blocks;
+ __u64 atime;
+ __u64 mtime;
+ __u64 ctime;
+ __u32 atimensec;
+ __u32 mtimensec;
+ __u32 ctimensec;
+ __u32 mode;
+ __u32 nlink;
+ __u32 uid;
+ __u32 gid;
+ __u32 rdev;
+};
+
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH 2/11] FUSE - core
2005-01-10 18:58 Miklos Szeredi
@ 2005-01-10 21:40 ` Mike Waychison
2005-01-10 22:28 ` Miklos Szeredi
2005-02-14 22:43 ` Faraz Ahmed
1 sibling, 1 reply; 11+ messages in thread
From: Mike Waychison @ 2005-01-10 21:40 UTC (permalink / raw)
To: Miklos Szeredi; +Cc: akpm, torvalds, linux-fsdevel, linux-kernel
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Miklos Szeredi wrote:
> This patch adds FUSE core.
>
> This contains the following files:
>
> o inode.c
> - superblock operations (alloc_inode, destroy_inode, read_inode,
> clear_inode, put_super, show_options)
> - registers FUSE filesystem
>
> o fuse_i.h
> - private header file
>
> Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
> diff -Nurp a/fs/fuse/Makefile b/fs/fuse/Makefile
> --- a/fs/fuse/Makefile 1970-01-01 01:00:00.000000000 +0100
> +++ b/fs/fuse/Makefile 2005-01-10 19:28:38.000000000 +0100
> @@ -0,0 +1,7 @@
> +#
> +# Makefile for the FUSE filesystem.
> +#
> +
> +obj-$(CONFIG_FUSE) += fuse.o
> +
> +fuse-objs := inode.o
> diff -Nurp a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
> --- a/fs/fuse/fuse_i.h 1970-01-01 01:00:00.000000000 +0100
> +++ b/fs/fuse/fuse_i.h 2005-01-10 19:28:38.000000000 +0100
> @@ -0,0 +1,90 @@
> +/*
> + FUSE: Filesystem in Userspace
> + Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
> +
> + This program can be distributed under the terms of the GNU GPL.
> + See the file COPYING.
> +*/
> +
> +#include <linux/fuse.h>
> +#include <linux/fs.h>
> +#include <linux/wait.h>
> +#include <linux/list.h>
> +#include <linux/spinlock.h>
> +#include <linux/mm.h>
> +#include <linux/backing-dev.h>
> +#include <asm/semaphore.h>
> +
> +/** FUSE specific inode data */
> +struct fuse_inode {
> + /** Unique ID, which identifies the inode between userspace
> + * and kernel */
> + u64 nodeid;
> +
> + /** Time in jiffies until the file attributes are valid */
> + unsigned long i_time;
> +};
> +
> +/**
> + * A Fuse connection.
> + *
> + * This structure is created, when the filesystem is mounted, and is
> + * destroyed, when the client device is closed and the filesystem is
> + * unmounted.
> + */
> +struct fuse_conn {
> + /** The superblock of the mounted filesystem */
> + struct super_block *sb;
> +
> + /** The user id for this mount */
> + uid_t user_id;
> +
> + /** Backing dev info */
> + struct backing_dev_info bdi;
> +};
> +
> +static inline struct fuse_conn **get_fuse_conn_super_p(struct super_block *sb)
> +{
> + return (struct fuse_conn **) &sb->s_fs_info;
> +}
> +
> +static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
> +{
> + return *get_fuse_conn_super_p(sb);
> +}
> +
> +static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
> +{
> + return get_fuse_conn_super(inode->i_sb);
> +}
> +
> +static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
> +{
> + return (struct fuse_inode *) (&inode[1]);
> +}
> +
> +static inline u64 get_node_id(struct inode *inode)
> +{
> + return get_fuse_inode(inode)->nodeid;
> +}
> +
> +/**
> + * This is the single global spinlock which protects FUSE's structures
> + *
> + * The following data is protected by this lock:
> + *
> + * - the private_data field of the device file
> + * - the s_fs_info field of the super block
> + * - unused_list, pending, processing lists in fuse_conn
> + * - the unique request ID counter reqctr in fuse_conn
> + * - the sb (super_block) field in fuse_conn
> + * - the file (device file) field in fuse_conn
> + */
These comments seem out of date. There is no unused_lsit, pending or
processing lists in fuse_conn. Nor is there a reqctr or file.
> +extern spinlock_t fuse_lock;
> +
> +/**
> + * Check if the connection can be released, and if yes, then free the
> + * connection structure
> + */
> +void fuse_release_conn(struct fuse_conn *fc);
> +
> diff -Nurp a/fs/fuse/inode.c b/fs/fuse/inode.c
> --- a/fs/fuse/inode.c 1970-01-01 01:00:00.000000000 +0100
> +++ b/fs/fuse/inode.c 2005-01-10 19:28:38.000000000 +0100
> @@ -0,0 +1,427 @@
> +/*
> + FUSE: Filesystem in Userspace
> + Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
> +
> + This program can be distributed under the terms of the GNU GPL.
> + See the file COPYING.
> +*/
> +
> +#include "fuse_i.h"
> +
> +#include <linux/pagemap.h>
> +#include <linux/slab.h>
> +#include <linux/file.h>
> +#include <linux/mount.h>
> +#include <linux/seq_file.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/parser.h>
> +#include <linux/statfs.h>
> +
> +MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
> +MODULE_DESCRIPTION("Filesystem in Userspace");
> +MODULE_LICENSE("GPL");
> +
> +spinlock_t fuse_lock;
> +static kmem_cache_t *fuse_inode_cachep;
> +static int mount_count;
> +
> +static int mount_max = 1000;
> +module_param(mount_max, int, 0644);
> +MODULE_PARM_DESC(mount_max, "Maximum number of FUSE mounts allowed, if -1 then unlimited (default: 1000)");
> +
> +#define FUSE_SUPER_MAGIC 0x65735546
> +
> +struct fuse_mount_data {
> + int fd;
> + unsigned rootmode;
> + unsigned user_id;
> +};
> +
> +static struct inode *fuse_alloc_inode(struct super_block *sb)
> +{
> + struct inode *inode;
> + struct fuse_inode *fi;
> +
> + inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
> + if (!inode)
> + return NULL;
> +
> + fi = get_fuse_inode(inode);
> + memset(fi, 0, sizeof(*fi));
> +
> + return inode;
> +}
> +
> +static void fuse_destroy_inode(struct inode *inode)
> +{
> + kmem_cache_free(fuse_inode_cachep, inode);
> +}
> +
> +static void fuse_read_inode(struct inode *inode)
> +{
> + /* No op */
> +}
> +
> +static void fuse_clear_inode(struct inode *inode)
> +{
> +}
> +
> +void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
> +{
> + if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
> + invalidate_inode_pages(inode->i_mapping);
> +
> + inode->i_ino = attr->ino;
> + inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
> + inode->i_nlink = attr->nlink;
> + inode->i_uid = attr->uid;
> + inode->i_gid = attr->gid;
> + i_size_write(inode, attr->size);
> + inode->i_blksize = PAGE_CACHE_SIZE;
> + inode->i_blocks = attr->blocks;
> + inode->i_atime.tv_sec = attr->atime;
> + inode->i_atime.tv_nsec = attr->atimensec;
> + inode->i_mtime.tv_sec = attr->mtime;
> + inode->i_mtime.tv_nsec = attr->mtimensec;
> + inode->i_ctime.tv_sec = attr->ctime;
> + inode->i_ctime.tv_nsec = attr->ctimensec;
> +}
> +
> +static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
> +{
> + inode->i_mode = attr->mode & S_IFMT;
> + i_size_write(inode, attr->size);
> +}
> +
> +static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
> +{
> + unsigned long nodeid = *(unsigned long *) _nodeidp;
> + if (get_node_id(inode) == nodeid)
> + return 1;
> + else
> + return 0;
> +}
> +
> +static int fuse_inode_set(struct inode *inode, void *_nodeidp)
> +{
> + unsigned long nodeid = *(unsigned long *) _nodeidp;
> + get_fuse_inode(inode)->nodeid = nodeid;
> + return 0;
> +}
> +
> +struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
> + int generation, struct fuse_attr *attr, int version)
> +{
> + struct inode *inode;
> + struct fuse_conn *fc = get_fuse_conn_super(sb);
> + int retried = 0;
> +
> + retry:
> + inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
> + if (!inode)
> + return NULL;
> +
> + if ((inode->i_state & I_NEW)) {
> + inode->i_generation = generation;
> + inode->i_data.backing_dev_info = &fc->bdi;
> + fuse_init_inode(inode, attr);
> + unlock_new_inode(inode);
> + } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
> + BUG_ON(retried);
> + /* Inode has changed type, any I/O on the old should fail */
> + make_bad_inode(inode);
> + iput(inode);
> + retried = 1;
> + goto retry;
> + }
> +
> + fuse_change_attributes(inode, attr);
> + inode->i_version = version;
> + return inode;
> +}
> +
> +static void fuse_put_super(struct super_block *sb)
> +{
> + struct fuse_conn *fc = get_fuse_conn_super(sb);
> +
> + spin_lock(&fuse_lock);
> + mount_count --;
> + fc->sb = NULL;
> + fc->user_id = 0;
> + fuse_release_conn(fc);
> + *get_fuse_conn_super_p(sb) = NULL;
> + spin_unlock(&fuse_lock);
> +}
> +
> +enum {
> + OPT_FD,
> + OPT_ROOTMODE,
> + OPT_USER_ID,
> + OPT_DEFAULT_PERMISSIONS,
> + OPT_ALLOW_OTHER,
> + OPT_ALLOW_ROOT,
> + OPT_KERNEL_CACHE,
> + OPT_ERR
> +};
> +
> +static match_table_t tokens = {
> + {OPT_FD, "fd=%u"},
> + {OPT_ROOTMODE, "rootmode=%o"},
> + {OPT_USER_ID, "user_id=%u"},
> + {OPT_DEFAULT_PERMISSIONS, "default_permissions"},
> + {OPT_ALLOW_OTHER, "allow_other"},
> + {OPT_ALLOW_ROOT, "allow_root"},
> + {OPT_KERNEL_CACHE, "kernel_cache"},
> + {OPT_ERR, NULL}
> +};
> +
> +static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
> +{
> + char *p;
> + memset(d, 0, sizeof(struct fuse_mount_data));
> + d->fd = -1;
> +
> + while ((p = strsep(&opt, ",")) != NULL) {
> + int token;
> + int value;
> + 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;
> + break;
> +
> + case OPT_ROOTMODE:
> + if (match_octal(&args[0], &value))
> + return 0;
> + d->rootmode = value;
> + break;
> +
> + case OPT_USER_ID:
> + if (match_int(&args[0], &value))
> + return 0;
> + d->user_id = value;
> + break;
> +
> + default:
> + return 0;
> + }
> + }
> + if (d->fd == -1)
> + return 0;
> +
> + return 1;
> +}
> +
> +static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
> +{
> + struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
> +
> + seq_printf(m, ",user_id=%u", fc->user_id);
> + return 0;
> +}
> +
> +void fuse_release_conn(struct fuse_conn *fc)
> +{
> + kfree(fc);
> +}
> +
> +static struct fuse_conn *new_conn(void)
> +{
> + struct fuse_conn *fc;
> +
> + fc = kmalloc(sizeof(*fc), GFP_KERNEL);
> + if (fc != NULL) {
> + memset(fc, 0, sizeof(*fc));
> + fc->sb = NULL;
> + fc->user_id = 0;
> + fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
> + fc->bdi.unplug_io_fn = default_unplug_io_fn;
> + }
> + return fc;
> +}
> +
> +static struct fuse_conn *get_conn(struct file *file, struct super_block *sb)
> +{
> + struct fuse_conn *fc;
> +
> + fc = new_conn();
> + if (fc == NULL)
> + return NULL;
> + spin_lock(&fuse_lock);
> + fc->sb = sb;
> + spin_unlock(&fuse_lock);
The lock here looks unnessary, fc is private to this function at this point.
> + return fc;
> +}
> +
> +static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
> +{
> + struct fuse_attr attr;
> + memset(&attr, 0, sizeof(attr));
> +
> + attr.mode = mode;
> + attr.ino = FUSE_ROOT_ID;
> + return fuse_iget(sb, 1, 0, &attr, 0);
> +}
> +
> +static struct super_operations fuse_super_operations = {
> + .alloc_inode = fuse_alloc_inode,
> + .destroy_inode = fuse_destroy_inode,
> + .read_inode = fuse_read_inode,
> + .clear_inode = fuse_clear_inode,
> + .put_super = fuse_put_super,
> + .show_options = fuse_show_options,
> +};
> +
> +static int inc_mount_count(void)
> +{
> + int success = 0;
> + spin_lock(&fuse_lock);
> + mount_count ++;
> + if (mount_max == -1 || mount_count <= mount_max)
> + success = 1;
> + spin_unlock(&fuse_lock);
> + return success;
> +}
> +
> +static int fuse_read_super(struct super_block *sb, void *data, int silent)
Can you rename this to fuse_fill_super so its consistent with what the
VFS calls it?
> +{
> + struct fuse_conn *fc;
> + struct inode *root;
> + struct fuse_mount_data d;
> + struct file *file;
> + int err;
> +
> + if (!parse_fuse_opt((char *) data, &d))
> + return -EINVAL;
> +
> + sb->s_blocksize = PAGE_CACHE_SIZE;
> + sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
> + sb->s_magic = FUSE_SUPER_MAGIC;
> + sb->s_op = &fuse_super_operations;
> + sb->s_maxbytes = MAX_LFS_FILESIZE;
> +
> + file = fget(d.fd);
> + if (!file)
> + return -EINVAL;
> +
> + fc = get_conn(file, sb);
> + fput(file);
> + if (fc == NULL)
> + return -EINVAL;
> +
> + fc->user_id = d.user_id;
> +
> + *get_fuse_conn_super_p(sb) = fc;
> +
> + err = -ENFILE;
> + if (!inc_mount_count() && current->uid != 0)
> + goto err;
> +
> + err = -ENOMEM;
> + root = get_root_inode(sb, d.rootmode);
> + if (root == NULL)
> + goto err;
> +
> + sb->s_root = d_alloc_root(root);
> + if (!sb->s_root) {
> + iput(root);
> + goto err;
> + }
> + return 0;
> +
> + err:
> + spin_lock(&fuse_lock);
> + mount_count --;
> + fc->sb = NULL;
> + fuse_release_conn(fc);
> + spin_unlock(&fuse_lock);
> + *get_fuse_conn_super_p(sb) = NULL;
> + return err;
> +}
> +
> +static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
> + int flags, const char *dev_name,
> + void *raw_data)
> +{
> + return get_sb_nodev(fs_type, flags, raw_data, fuse_read_super);
> +}
> +
> +static struct file_system_type fuse_fs_type = {
> + .owner = THIS_MODULE,
> + .name = "fuse",
> + .get_sb = fuse_get_sb,
> + .kill_sb = kill_anon_super,
> +};
> +
> +static void fuse_inode_init_once(void * foo, kmem_cache_t * cachep,
> + unsigned long flags)
> +{
> + struct inode * inode = foo;
> +
> + if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
> + SLAB_CTOR_CONSTRUCTOR)
> + inode_init_once(inode);
> +}
> +
> +static int __init fuse_fs_init(void)
> +{
> + int err;
> +
> + err = register_filesystem(&fuse_fs_type);
> + if (err)
> + printk("fuse: failed to register filesystem\n");
> + else {
> + fuse_inode_cachep = kmem_cache_create("fuse_inode",
> + sizeof(struct inode) + sizeof(struct fuse_inode) ,
I'm not convinced this will get the right alignments in the case where
struct inode ever changes size. You're better off using a new struct
that contains both and using the size of it here, as well as using it
for calculating the offset in get_fuse_inode instead of &inode[1].
> + 0, SLAB_HWCACHE_ALIGN,
> + fuse_inode_init_once, NULL);
> + if (!fuse_inode_cachep) {
> + unregister_filesystem(&fuse_fs_type);
> + err = -ENOMEM;
> + }
> + }
> +
> + return err;
> +}
> +
> +static void fuse_fs_cleanup(void)
> +{
> + unregister_filesystem(&fuse_fs_type);
> + kmem_cache_destroy(fuse_inode_cachep);
> +}
> +
> +int __init fuse_init(void)
static?
> +{
> + int res;
> +
> + printk("fuse init (API version %i.%i)\n",
> + FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
> +
> + spin_lock_init(&fuse_lock);
> + res = fuse_fs_init();
> + if (res)
> + goto err;
> +
> + return 0;
> +
> + err:
> + return res;
> +}
> +
> +void __exit fuse_exit(void)
static?
> +{
> + printk(KERN_DEBUG "fuse exit\n");
> +
> + fuse_fs_cleanup();
> +}
Why not just do the cleanup here? If you still want to keep fuse_exit
seperate from fuse_fs_cleanup, may I suggest marking the former __exit?
> +
> +module_init(fuse_init);
> +module_exit(fuse_exit);
> diff -Nurp a/include/linux/fuse.h b/include/linux/fuse.h
> --- a/include/linux/fuse.h 1970-01-01 01:00:00.000000000 +0100
> +++ b/include/linux/fuse.h 2005-01-10 19:28:38.000000000 +0100
> @@ -0,0 +1,38 @@
> +/*
> + FUSE: Filesystem in Userspace
> + Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu>
> +
> + This program can be distributed under the terms of the GNU GPL.
> + See the file COPYING.
> +*/
> +
> +/* This file defines the kernel interface of FUSE */
> +
> +#include <asm/types.h>
> +
> +/** Version number of this interface */
> +#define FUSE_KERNEL_VERSION 5
> +
> +/** Minor version number of this interface */
> +#define FUSE_KERNEL_MINOR_VERSION 1
I haven't yet looked at the other patches, but is this VERSION info
negotiated with userspace?
> +
> +/** The node ID of the root inode */
> +#define FUSE_ROOT_ID 1
> +
> +struct fuse_attr {
> + __u64 ino;
> + __u64 size;
> + __u64 blocks;
> + __u64 atime;
> + __u64 mtime;
> + __u64 ctime;
> + __u32 atimensec;
> + __u32 mtimensec;
> + __u32 ctimensec;
> + __u32 mode;
> + __u32 nlink;
> + __u32 uid;
> + __u32 gid;
> + __u32 rdev;
> +};
> +
> -
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
- --
Mike Waychison
Sun Microsystems, Inc.
1 (650) 352-5299 voice
1 (416) 202-8336 voice
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NOTICE: The opinions expressed in this email are held by me,
and may not represent the views of Sun Microsystems, Inc.
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^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH 2/11] FUSE - core
2005-01-10 21:40 ` Mike Waychison
@ 2005-01-10 22:28 ` Miklos Szeredi
0 siblings, 0 replies; 11+ messages in thread
From: Miklos Szeredi @ 2005-01-10 22:28 UTC (permalink / raw)
To: Michael.Waychison; +Cc: akpm, torvalds, linux-fsdevel, linux-kernel
> > + *
> > + * - the private_data field of the device file
> > + * - the s_fs_info field of the super block
> > + * - unused_list, pending, processing lists in fuse_conn
> > + * - the unique request ID counter reqctr in fuse_conn
> > + * - the sb (super_block) field in fuse_conn
> > + * - the file (device file) field in fuse_conn
> > + */
>
> These comments seem out of date. There is no unused_lsit, pending or
> processing lists in fuse_conn. Nor is there a reqctr or file.
>
[...]
> > + return NULL;
> > + spin_lock(&fuse_lock);
> > + fc->sb = sb;
> > + spin_unlock(&fuse_lock);
>
> The lock here looks unnessary, fc is private to this function at this point.
Yes, well these are caused by the split. Later patches will explain
these. I could split up the comment too...
> > +static int fuse_read_super(struct super_block *sb, void *data, int silent)
>
> Can you rename this to fuse_fill_super so its consistent with what the
> VFS calls it?
Yes.
> > + fuse_inode_cachep = kmem_cache_create("fuse_inode",
> > + sizeof(struct inode) + sizeof(struct fuse_inode) ,
>
> I'm not convinced this will get the right alignments in the case where
> struct inode ever changes size. You're better off using a new struct
> that contains both and using the size of it here, as well as using it
> for calculating the offset in get_fuse_inode instead of &inode[1].
Good point. I haven't thought of this.
> > +int __init fuse_init(void)
>
> static?
OK.
> > +{
> > + printk(KERN_DEBUG "fuse exit\n");
> > +
> > + fuse_fs_cleanup();
> > +}
>
> Why not just do the cleanup here? If you still want to keep fuse_exit
> seperate from fuse_fs_cleanup, may I suggest marking the former __exit?
Again, later patches explain this.
> > +/** Version number of this interface */
> > +#define FUSE_KERNEL_VERSION 5
> > +
> > +/** Minor version number of this interface */
> > +#define FUSE_KERNEL_MINOR_VERSION 1
>
> I haven't yet looked at the other patches, but is this VERSION info
> negotiated with userspace?
Yes.
Thanks for the comments!
Miklos
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 2/11] FUSE - core
2005-01-10 18:58 Miklos Szeredi
2005-01-10 21:40 ` Mike Waychison
@ 2005-02-14 22:43 ` Faraz Ahmed
1 sibling, 0 replies; 11+ messages in thread
From: Faraz Ahmed @ 2005-02-14 22:43 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel
unsubscribe
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2005-02-16 7:16 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2005-01-11 16:25 [PATCH 2/11] FUSE - core Miklos Szeredi
2005-01-12 22:36 ` Andrew Morton
2005-01-13 5:31 ` Miklos Szeredi
2005-01-14 13:55 ` Anton Altaparmakov
2005-01-14 14:07 ` Miklos Szeredi
2005-01-14 14:14 ` Anton Altaparmakov
2005-01-14 14:32 ` Miklos Szeredi
-- strict thread matches above, loose matches on Subject: below --
2005-01-10 18:58 Miklos Szeredi
2005-01-10 21:40 ` Mike Waychison
2005-01-10 22:28 ` Miklos Szeredi
2005-02-14 22:43 ` Faraz Ahmed
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