diff options
Diffstat (limited to 'fs/ecryptfs/main.c')
| -rw-r--r-- | fs/ecryptfs/main.c | 166 |
1 files changed, 81 insertions, 85 deletions
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index 760983d0f25e..cbd4e18adb20 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -281,7 +281,7 @@ static void ecryptfs_init_mount_crypt_stat( * * Returns zero on success; non-zero on error */ -static int ecryptfs_parse_options(struct super_block *sb, char *options) +static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options) { char *p; int rc = 0; @@ -293,7 +293,7 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options) int fn_cipher_key_bytes; int fn_cipher_key_bytes_set = 0; struct ecryptfs_mount_crypt_stat *mount_crypt_stat = - &ecryptfs_superblock_to_private(sb)->mount_crypt_stat; + &sbi->mount_crypt_stat; substring_t args[MAX_OPT_ARGS]; int token; char *sig_src; @@ -483,68 +483,7 @@ out: } struct kmem_cache *ecryptfs_sb_info_cache; - -/** - * ecryptfs_fill_super - * @sb: The ecryptfs super block - * @raw_data: The options passed to mount - * @silent: Not used but required by function prototype - * - * Sets up what we can of the sb, rest is done in ecryptfs_read_super - * - * Returns zero on success; non-zero otherwise - */ -static int -ecryptfs_fill_super(struct super_block *sb, void *raw_data, int silent) -{ - struct ecryptfs_sb_info *esi; - int rc = 0; - - /* Released in ecryptfs_put_super() */ - ecryptfs_set_superblock_private(sb, - kmem_cache_zalloc(ecryptfs_sb_info_cache, - GFP_KERNEL)); - esi = ecryptfs_superblock_to_private(sb); - if (!esi) { - ecryptfs_printk(KERN_WARNING, "Out of memory\n"); - rc = -ENOMEM; - goto out; - } - - rc = bdi_setup_and_register(&esi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); - if (rc) - goto out; - - sb->s_bdi = &esi->bdi; - sb->s_op = &ecryptfs_sops; - /* Released through deactivate_super(sb) from get_sb_nodev */ - sb->s_root = d_alloc(NULL, &(const struct qstr) { - .hash = 0,.name = "/",.len = 1}); - if (!sb->s_root) { - ecryptfs_printk(KERN_ERR, "d_alloc failed\n"); - rc = -ENOMEM; - goto out; - } - sb->s_root->d_op = &ecryptfs_dops; - sb->s_root->d_sb = sb; - sb->s_root->d_parent = sb->s_root; - /* Released in d_release when dput(sb->s_root) is called */ - /* through deactivate_super(sb) from get_sb_nodev() */ - ecryptfs_set_dentry_private(sb->s_root, - kmem_cache_zalloc(ecryptfs_dentry_info_cache, - GFP_KERNEL)); - if (!ecryptfs_dentry_to_private(sb->s_root)) { - ecryptfs_printk(KERN_ERR, - "dentry_info_cache alloc failed\n"); - rc = -ENOMEM; - goto out; - } - rc = 0; -out: - /* Should be able to rely on deactivate_super called from - * get_sb_nodev */ - return rc; -} +static struct file_system_type ecryptfs_fs_type; /** * ecryptfs_read_super @@ -565,6 +504,13 @@ static int ecryptfs_read_super(struct super_block *sb, const char *dev_name) ecryptfs_printk(KERN_WARNING, "path_lookup() failed\n"); goto out; } + if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { + rc = -EINVAL; + printk(KERN_ERR "Mount on filesystem of type " + "eCryptfs explicitly disallowed due to " + "known incompatibilities\n"); + goto out_free; + } ecryptfs_set_superblock_lower(sb, path.dentry->d_sb); sb->s_maxbytes = path.dentry->d_sb->s_maxbytes; sb->s_blocksize = path.dentry->d_sb->s_blocksize; @@ -588,11 +534,8 @@ out: * @dev_name: The path to mount over * @raw_data: The options passed into the kernel * - * The whole ecryptfs_get_sb process is broken into 4 functions: + * The whole ecryptfs_get_sb process is broken into 3 functions: * ecryptfs_parse_options(): handle options passed to ecryptfs, if any - * ecryptfs_fill_super(): used by get_sb_nodev, fills out the super_block - * with as much information as it can before needing - * the lower filesystem. * ecryptfs_read_super(): this accesses the lower filesystem and uses * ecryptfs_interpose to perform most of the linking * ecryptfs_interpose(): links the lower filesystem into ecryptfs (inode.c) @@ -601,30 +544,78 @@ static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt) { + struct super_block *s; + struct ecryptfs_sb_info *sbi; + struct ecryptfs_dentry_info *root_info; + const char *err = "Getting sb failed"; int rc; - struct super_block *sb; - rc = get_sb_nodev(fs_type, flags, raw_data, ecryptfs_fill_super, mnt); - if (rc < 0) { - printk(KERN_ERR "Getting sb failed; rc = [%d]\n", rc); + sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); + if (!sbi) { + rc = -ENOMEM; goto out; } - sb = mnt->mnt_sb; - rc = ecryptfs_parse_options(sb, raw_data); + + rc = ecryptfs_parse_options(sbi, raw_data); if (rc) { - printk(KERN_ERR "Error parsing options; rc = [%d]\n", rc); - goto out_abort; + err = "Error parsing options"; + goto out; + } + + s = sget(fs_type, NULL, set_anon_super, NULL); + if (IS_ERR(s)) { + rc = PTR_ERR(s); + goto out; } - rc = ecryptfs_read_super(sb, dev_name); + + s->s_flags = flags; + rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); if (rc) { - printk(KERN_ERR "Reading sb failed; rc = [%d]\n", rc); - goto out_abort; + deactivate_locked_super(s); + goto out; } - goto out; -out_abort: - dput(sb->s_root); /* aka mnt->mnt_root, as set by get_sb_nodev() */ - deactivate_locked_super(sb); + + ecryptfs_set_superblock_private(s, sbi); + s->s_bdi = &sbi->bdi; + + /* ->kill_sb() will take care of sbi after that point */ + sbi = NULL; + s->s_op = &ecryptfs_sops; + + rc = -ENOMEM; + s->s_root = d_alloc(NULL, &(const struct qstr) { + .hash = 0,.name = "/",.len = 1}); + if (!s->s_root) { + deactivate_locked_super(s); + goto out; + } + s->s_root->d_op = &ecryptfs_dops; + s->s_root->d_sb = s; + s->s_root->d_parent = s->s_root; + + root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); + if (!root_info) { + deactivate_locked_super(s); + goto out; + } + /* ->kill_sb() will take care of root_info */ + ecryptfs_set_dentry_private(s->s_root, root_info); + s->s_flags |= MS_ACTIVE; + rc = ecryptfs_read_super(s, dev_name); + if (rc) { + deactivate_locked_super(s); + err = "Reading sb failed"; + goto out; + } + simple_set_mnt(mnt, s); + return 0; + out: + if (sbi) { + ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); + kmem_cache_free(ecryptfs_sb_info_cache, sbi); + } + printk(KERN_ERR "%s; rc = [%d]\n", err, rc); return rc; } @@ -633,11 +624,16 @@ out: * @sb: The ecryptfs super block * * Used to bring the superblock down and free the private data. - * Private data is free'd in ecryptfs_put_super() */ static void ecryptfs_kill_block_super(struct super_block *sb) { - generic_shutdown_super(sb); + struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); + kill_anon_super(sb); + if (!sb_info) + return; + ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); + bdi_destroy(&sb_info->bdi); + kmem_cache_free(ecryptfs_sb_info_cache, sb_info); } static struct file_system_type ecryptfs_fs_type = { |