diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/fuse_i.h | 19 | ||||
| -rw-r--r-- | kernel/inode.c | 141 |
2 files changed, 139 insertions, 21 deletions
diff --git a/kernel/fuse_i.h b/kernel/fuse_i.h index 6f064fe..1299139 100644 --- a/kernel/fuse_i.h +++ b/kernel/fuse_i.h @@ -43,6 +43,25 @@ #define FUSE_BLOCK_PAGE_SHIFT (FUSE_BLOCK_SHIFT - PAGE_CACHE_SHIFT) +/** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem +module will check permissions based on the file mode. Otherwise no +permission checking is done in the kernel */ +#define FUSE_DEFAULT_PERMISSIONS (1 << 0) + +/** If the FUSE_ALLOW_OTHER flag is given, then not only the user + doing the mount will be allowed to access the filesystem */ +#define FUSE_ALLOW_OTHER (1 << 1) + +/** If the FUSE_KERNEL_CACHE flag is given, then files will be cached + until the INVALIDATE operation is invoked */ +#define FUSE_KERNEL_CACHE (1 << 2) + +/** Allow FUSE to combine reads into 64k chunks. This is useful if + the filesystem is better at handling large chunks. NOTE: in + current implementation the raw throughput is worse for large reads + than for small. */ +#define FUSE_LARGE_READ (1 << 3) + /** * A Fuse connection. * diff --git a/kernel/inode.c b/kernel/inode.c index 17c0f60..a719ad9 100644 --- a/kernel/inode.c +++ b/kernel/inode.c @@ -12,7 +12,10 @@ #include <linux/sched.h> #include <linux/slab.h> #include <linux/file.h> +#include <linux/mount.h> #include <linux/proc_fs.h> +#include <linux/parser.h> +#include <linux/seq_file.h> #ifdef KERNEL_2_6 #include <linux/statfs.h> #endif @@ -26,9 +29,13 @@ #ifndef FS_SAFE #define FS_SAFE 0 #endif -#ifndef FS_BINARY_MOUNTDATA -#define FS_BINARY_MOUNTDATA 0 -#endif + +struct fuse_mount_data { + int fd; + unsigned int rootmode; + unsigned int uid; + unsigned int flags; +}; static void fuse_read_inode(struct inode *inode) { @@ -111,24 +118,113 @@ static int fuse_statfs(struct super_block *sb, struct kstatfs *buf) return out.h.error; } -static struct fuse_conn *get_conn(struct fuse_mount_data *d) +enum { opt_fd, opt_rootmode, opt_uid, opt_default_permissions, + opt_allow_other, opt_kernel_cache, opt_large_read, opt_err }; + +static match_table_t tokens = { + {opt_fd, "fd=%u"}, + {opt_rootmode, "rootmode=%o"}, + {opt_uid, "uid=%u"}, + {opt_default_permissions, "default_permissions"}, + {opt_allow_other, "allow_other"}, + {opt_kernel_cache, "kernel_cache"}, + {opt_large_read, "large_read"}, + {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; + + if (opt == NULL) + return 0; + + if (opt[PAGE_SIZE - 1] != '\0') + return 0; + + 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_uid: + if (match_int(&args[0], &value)) + return 0; + d->uid = value; + break; + + case opt_default_permissions: + d->flags |= FUSE_DEFAULT_PERMISSIONS; + break; + + case opt_allow_other: + d->flags |= FUSE_ALLOW_OTHER; + break; + + case opt_kernel_cache: + d->flags |= FUSE_KERNEL_CACHE; + break; + + case opt_large_read: + d->flags |= FUSE_LARGE_READ; + 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 = SB_FC(mnt->mnt_sb); + + seq_printf(m, ",uid=%u", fc->uid); + if (fc->flags & FUSE_DEFAULT_PERMISSIONS) + seq_puts(m, ",default_permissions"); + if (fc->flags & FUSE_ALLOW_OTHER) + seq_puts(m, ",allow_other"); + if (fc->flags & FUSE_KERNEL_CACHE) + seq_puts(m, ",kernel_cache"); + if (fc->flags & FUSE_LARGE_READ) + seq_puts(m, ",large_read"); + return 0; +} + +static struct fuse_conn *get_conn(int fd) { struct fuse_conn *fc = NULL; struct file *file; struct inode *ino; - if (d == NULL) { - printk("fuse_read_super: Bad mount data\n"); - return NULL; - } - - file = fget(d->fd); + file = fget(fd); ino = NULL; if (file) ino = file->f_dentry->d_inode; if (!ino || !proc_fuse_dev || proc_fuse_dev->low_ino != ino->i_ino) { - printk("fuse_read_super: Bad file: %i\n", d->fd); + printk("FUSE: bad communication file descriptor: %i\n", fd); goto out; } @@ -186,18 +282,20 @@ static struct super_operations fuse_super_operations = { .clear_inode = fuse_clear_inode, .put_super = fuse_put_super, .statfs = fuse_statfs, + .show_options = fuse_show_options, }; 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 = data; + struct fuse_mount_data d; - if (!capable(CAP_SYS_ADMIN)) { - if (d->flags & FUSE_ALLOW_OTHER) - return -EPERM; - } + if (!parse_fuse_opt((char *) data, &d)) + return -EINVAL; + + if ((d.flags & FUSE_ALLOW_OTHER) && !capable(CAP_SYS_ADMIN)) + return -EPERM; sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; @@ -208,9 +306,10 @@ static int fuse_read_super(struct super_block *sb, void *data, int silent) sb->s_export_op = &fuse_export_operations; #endif - fc = get_conn(d); + fc = get_conn(d.fd); if (fc == NULL) return -EINVAL; + spin_lock(&fuse_lock); if (fc->sb != NULL) { printk("fuse_read_super: connection already mounted\n"); @@ -218,15 +317,15 @@ static int fuse_read_super(struct super_block *sb, void *data, int silent) return -EINVAL; } fc->sb = sb; - fc->flags = d->flags; - fc->uid = d->uid; + fc->flags = d.flags; + fc->uid = d.uid; spin_unlock(&fuse_lock); /* fc is needed in fuse_init_file_inode which could be called from get_root_inode */ SB_FC(sb) = fc; - root = get_root_inode(sb, d->rootmode); + root = get_root_inode(sb, d.rootmode); if (root == NULL) { printk("fuse_read_super: failed to get root inode\n"); return -EINVAL; @@ -252,7 +351,7 @@ static struct file_system_type fuse_fs_type = { .name = "fuse", .get_sb = fuse_get_sb, .kill_sb = kill_anon_super, - .fs_flags = FS_SAFE | FS_BINARY_MOUNTDATA, + .fs_flags = FS_SAFE, }; #else static struct super_block *fuse_read_super_compat(struct super_block *sb, |