diff options
Diffstat (limited to 'fs/filesystems.c')
| -rw-r--r-- | fs/filesystems.c | 80 |
1 files changed, 46 insertions, 34 deletions
diff --git a/fs/filesystems.c b/fs/filesystems.c index 92567d95ba6a..95e5256821a5 100644 --- a/fs/filesystems.c +++ b/fs/filesystems.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * linux/fs/filesystems.c * @@ -14,7 +15,8 @@ #include <linux/init.h> #include <linux/module.h> #include <linux/slab.h> -#include <asm/uaccess.h> +#include <linux/uaccess.h> +#include <linux/fs_parser.h> /* * Handling of filesystem drivers list. @@ -33,9 +35,10 @@ static struct file_system_type *file_systems; static DEFINE_RWLOCK(file_systems_lock); /* WARNING: This can be used only if we _already_ own a reference */ -void get_filesystem(struct file_system_type *fs) +struct file_system_type *get_filesystem(struct file_system_type *fs) { __module_get(fs->owner); + return fs; } void put_filesystem(struct file_system_type *fs) @@ -46,9 +49,9 @@ void put_filesystem(struct file_system_type *fs) static struct file_system_type **find_filesystem(const char *name, unsigned len) { struct file_system_type **p; - for (p=&file_systems; *p; p=&(*p)->next) - if (strlen((*p)->name) == len && - strncmp((*p)->name, name, len) == 0) + for (p = &file_systems; *p; p = &(*p)->next) + if (strncmp((*p)->name, name, len) == 0 && + !(*p)->name[len]) break; return p; } @@ -71,6 +74,10 @@ int register_filesystem(struct file_system_type * fs) int res = 0; struct file_system_type ** p; + if (fs->parameters && + !fs_validate_description(fs->name, fs->parameters)) + return -EINVAL; + BUG_ON(strchr(fs->name, '.')); if (fs->next) return -EBUSY; @@ -121,6 +128,7 @@ int unregister_filesystem(struct file_system_type * fs) EXPORT_SYMBOL(unregister_filesystem); +#ifdef CONFIG_SYSFS_SYSCALL static int fs_index(const char __user * __name) { struct file_system_type * tmp; @@ -148,15 +156,19 @@ static int fs_index(const char __user * __name) static int fs_name(unsigned int index, char __user * buf) { struct file_system_type * tmp; - int len, res; + int len, res = -EINVAL; read_lock(&file_systems_lock); - for (tmp = file_systems; tmp; tmp = tmp->next, index--) - if (index <= 0 && try_module_get(tmp->owner)) + for (tmp = file_systems; tmp; tmp = tmp->next, index--) { + if (index == 0) { + if (try_module_get(tmp->owner)) + res = 0; break; + } + } read_unlock(&file_systems_lock); - if (!tmp) - return -EINVAL; + if (res) + return res; /* OK, we got the reference, so we can safely block */ len = strlen(tmp->name) + 1; @@ -199,22 +211,30 @@ SYSCALL_DEFINE3(sysfs, int, option, unsigned long, arg1, unsigned long, arg2) } return retval; } +#endif -int __init get_filesystem_list(char *buf) +int __init list_bdev_fs_names(char *buf, size_t size) { - int len = 0; - struct file_system_type * tmp; + struct file_system_type *p; + size_t len; + int count = 0; read_lock(&file_systems_lock); - tmp = file_systems; - while (tmp && len < PAGE_SIZE - 80) { - len += sprintf(buf+len, "%s\t%s\n", - (tmp->fs_flags & FS_REQUIRES_DEV) ? "" : "nodev", - tmp->name); - tmp = tmp->next; + for (p = file_systems; p; p = p->next) { + if (!(p->fs_flags & FS_REQUIRES_DEV)) + continue; + len = strlen(p->name) + 1; + if (len > size) { + pr_warn("%s: truncating file system list\n", __func__); + break; + } + memcpy(buf, p->name, len); + buf += len; + size -= len; + count++; } read_unlock(&file_systems_lock); - return len; + return count; } #ifdef CONFIG_PROC_FS @@ -234,21 +254,9 @@ static int filesystems_proc_show(struct seq_file *m, void *v) return 0; } -static int filesystems_proc_open(struct inode *inode, struct file *file) -{ - return single_open(file, filesystems_proc_show, NULL); -} - -static const struct file_operations filesystems_proc_fops = { - .open = filesystems_proc_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; - static int __init proc_filesystems_init(void) { - proc_create("filesystems", 0, NULL, &filesystems_proc_fops); + proc_create_single("filesystems", 0, NULL, filesystems_proc_show); return 0; } module_init(proc_filesystems_init); @@ -273,8 +281,12 @@ struct file_system_type *get_fs_type(const char *name) int len = dot ? dot - name : strlen(name); fs = __get_fs_type(name, len); - if (!fs && (request_module("fs-%.*s", len, name) == 0)) + if (!fs && (request_module("fs-%.*s", len, name) == 0)) { fs = __get_fs_type(name, len); + if (!fs) + pr_warn_once("request_module fs-%.*s succeeded, but still no fs?\n", + len, name); + } if (dot && fs && !(fs->fs_flags & FS_HAS_SUBTYPE)) { put_filesystem(fs); |