diff options
| -rw-r--r-- | fs/ecryptfs/ecryptfs_kernel.h | 5 | ||||
| -rw-r--r-- | fs/ecryptfs/file.c | 22 | ||||
| -rw-r--r-- | fs/ecryptfs/inode.c | 30 | ||||
| -rw-r--r-- | fs/ecryptfs/kthread.c | 6 | ||||
| -rw-r--r-- | fs/ecryptfs/main.c | 72 | ||||
| -rw-r--r-- | fs/ecryptfs/super.c | 16 |
6 files changed, 92 insertions, 59 deletions
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index bd3cafd..380bee1 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -295,6 +295,8 @@ struct ecryptfs_crypt_stat { struct ecryptfs_inode_info { struct inode vfs_inode; struct inode *wii_inode; + struct mutex lower_file_mutex; + atomic_t lower_file_count; struct file *lower_file; struct ecryptfs_crypt_stat crypt_stat; }; @@ -757,7 +759,8 @@ int ecryptfs_privileged_open(struct file **lower_file, struct dentry *lower_dentry, struct vfsmount *lower_mnt, const struct cred *cred); -int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry); +int ecryptfs_get_lower_file(struct dentry *ecryptfs_dentry); +void ecryptfs_put_lower_file(struct inode *inode); int ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, size_t *packet_size, diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index cedc913..146c4ed 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -191,10 +191,10 @@ static int ecryptfs_open(struct inode *inode, struct file *file) | ECRYPTFS_ENCRYPTED); } mutex_unlock(&crypt_stat->cs_mutex); - rc = ecryptfs_init_persistent_file(ecryptfs_dentry); + rc = ecryptfs_get_lower_file(ecryptfs_dentry); if (rc) { printk(KERN_ERR "%s: Error attempting to initialize " - "the persistent file for the dentry with name " + "the lower file for the dentry with name " "[%s]; rc = [%d]\n", __func__, ecryptfs_dentry->d_name.name, rc); goto out_free; @@ -202,9 +202,9 @@ static int ecryptfs_open(struct inode *inode, struct file *file) if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_ACCMODE) == O_RDONLY && (file->f_flags & O_ACCMODE) != O_RDONLY) { rc = -EPERM; - printk(KERN_WARNING "%s: Lower persistent file is RO; eCryptfs " + printk(KERN_WARNING "%s: Lower file is RO; eCryptfs " "file must hence be opened RO\n", __func__); - goto out_free; + goto out_put; } ecryptfs_set_file_lower( file, ecryptfs_inode_to_private(inode)->lower_file); @@ -232,7 +232,7 @@ static int ecryptfs_open(struct inode *inode, struct file *file) "Plaintext passthrough mode is not " "enabled; returning -EIO\n"); mutex_unlock(&crypt_stat->cs_mutex); - goto out_free; + goto out_put; } rc = 0; crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); @@ -245,6 +245,8 @@ static int ecryptfs_open(struct inode *inode, struct file *file) "[0x%.16lx] size: [0x%.16llx]\n", inode, inode->i_ino, (unsigned long long)i_size_read(inode)); goto out; +out_put: + ecryptfs_put_lower_file(inode); out_free: kmem_cache_free(ecryptfs_file_info_cache, ecryptfs_file_to_private(file)); @@ -254,17 +256,13 @@ out: static int ecryptfs_flush(struct file *file, fl_owner_t td) { - int rc = 0; - struct file *lower_file = NULL; - - lower_file = ecryptfs_file_to_lower(file); - if (lower_file->f_op && lower_file->f_op->flush) - rc = lower_file->f_op->flush(lower_file, td); - return rc; + return file->f_mode & FMODE_WRITE + ? filemap_write_and_wait(file->f_mapping) : 0; } static int ecryptfs_release(struct inode *inode, struct file *file) { + ecryptfs_put_lower_file(inode); kmem_cache_free(ecryptfs_file_info_cache, ecryptfs_file_to_private(file)); return 0; diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 72d3576..f6b3886 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -168,19 +168,18 @@ static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry) "context; rc = [%d]\n", rc); goto out; } - rc = ecryptfs_init_persistent_file(ecryptfs_dentry); + rc = ecryptfs_get_lower_file(ecryptfs_dentry); if (rc) { printk(KERN_ERR "%s: Error attempting to initialize " - "the persistent file for the dentry with name " + "the lower file for the dentry with name " "[%s]; rc = [%d]\n", __func__, ecryptfs_dentry->d_name.name, rc); goto out; } rc = ecryptfs_write_metadata(ecryptfs_dentry); - if (rc) { + if (rc) printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc); - goto out; - } + ecryptfs_put_lower_file(ecryptfs_dentry->d_inode); out: return rc; } @@ -230,7 +229,7 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, struct ecryptfs_crypt_stat *crypt_stat; char *page_virt = NULL; u64 file_size; - int rc = 0; + int put_lower = 0, rc = 0; lower_dir_dentry = lower_dentry->d_parent; lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt( @@ -277,14 +276,15 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, rc = -ENOMEM; goto out; } - rc = ecryptfs_init_persistent_file(ecryptfs_dentry); + rc = ecryptfs_get_lower_file(ecryptfs_dentry); if (rc) { printk(KERN_ERR "%s: Error attempting to initialize " - "the persistent file for the dentry with name " + "the lower file for the dentry with name " "[%s]; rc = [%d]\n", __func__, ecryptfs_dentry->d_name.name, rc); goto out_free_kmem; } + put_lower = 1; crypt_stat = &ecryptfs_inode_to_private( ecryptfs_dentry->d_inode)->crypt_stat; /* TODO: lock for crypt_stat comparison */ @@ -322,6 +322,8 @@ out_put: mntput(lower_mnt); d_drop(ecryptfs_dentry); out: + if (put_lower) + ecryptfs_put_lower_file(ecryptfs_dentry->d_inode); return rc; } @@ -757,8 +759,11 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia, if (unlikely((ia->ia_size == i_size))) { lower_ia->ia_valid &= ~ATTR_SIZE; - goto out; + return 0; } + rc = ecryptfs_get_lower_file(dentry); + if (rc) + return rc; crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; /* Switch on growing or shrinking file */ if (ia->ia_size > i_size) { @@ -836,6 +841,7 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia, lower_ia->ia_valid &= ~ATTR_SIZE; } out: + ecryptfs_put_lower_file(inode); return rc; } @@ -911,7 +917,13 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) mount_crypt_stat = &ecryptfs_superblock_to_private( dentry->d_sb)->mount_crypt_stat; + rc = ecryptfs_get_lower_file(dentry); + if (rc) { + mutex_unlock(&crypt_stat->cs_mutex); + goto out; + } rc = ecryptfs_read_metadata(dentry); + ecryptfs_put_lower_file(inode); if (rc) { if (!(mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) { diff --git a/fs/ecryptfs/kthread.c b/fs/ecryptfs/kthread.c index 0851ab6..69f994a 100644 --- a/fs/ecryptfs/kthread.c +++ b/fs/ecryptfs/kthread.c @@ -44,7 +44,7 @@ static struct task_struct *ecryptfs_kthread; * @ignored: ignored * * The eCryptfs kernel thread that has the responsibility of getting - * the lower persistent file with RW permissions. + * the lower file with RW permissions. * * Returns zero on success; non-zero otherwise */ @@ -141,8 +141,8 @@ int ecryptfs_privileged_open(struct file **lower_file, int rc = 0; /* Corresponding dput() and mntput() are done when the - * persistent file is fput() when the eCryptfs inode is - * destroyed. */ + * lower file is fput() when all eCryptfs files for the inode are + * released. */ dget(lower_dentry); mntget(lower_mnt); flags |= IS_RDONLY(lower_dentry->d_inode) ? O_RDONLY : O_RDWR; diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index fdb2eb0..89b9338 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -96,7 +96,7 @@ void __ecryptfs_printk(const char *fmt, ...) } /** - * ecryptfs_init_persistent_file + * ecryptfs_init_lower_file * @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with * the lower dentry and the lower mount set * @@ -104,42 +104,70 @@ void __ecryptfs_printk(const char *fmt, ...) * inode. All I/O operations to the lower inode occur through that * file. When the first eCryptfs dentry that interposes with the first * lower dentry for that inode is created, this function creates the - * persistent file struct and associates it with the eCryptfs - * inode. When the eCryptfs inode is destroyed, the file is closed. + * lower file struct and associates it with the eCryptfs + * inode. When all eCryptfs files associated with the inode are released, the + * file is closed. * - * The persistent file will be opened with read/write permissions, if + * The lower file will be opened with read/write permissions, if * possible. Otherwise, it is opened read-only. * - * This function does nothing if a lower persistent file is already + * This function does nothing if a lower file is already * associated with the eCryptfs inode. * * Returns zero on success; non-zero otherwise */ -int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry) +static int ecryptfs_init_lower_file(struct dentry *dentry, + struct file **lower_file) { const struct cred *cred = current_cred(); - struct ecryptfs_inode_info *inode_info = - ecryptfs_inode_to_private(ecryptfs_dentry->d_inode); - int rc = 0; + struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); + struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); + int rc; - if (!inode_info->lower_file) { - struct dentry *lower_dentry; - struct vfsmount *lower_mnt = - ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry); + rc = ecryptfs_privileged_open(lower_file, lower_dentry, lower_mnt, + cred); + if (rc) { + printk(KERN_ERR "Error opening lower file " + "for lower_dentry [0x%p] and lower_mnt [0x%p]; " + "rc = [%d]\n", lower_dentry, lower_mnt, rc); + (*lower_file) = NULL; + } + return rc; +} - lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); - rc = ecryptfs_privileged_open(&inode_info->lower_file, - lower_dentry, lower_mnt, cred); - if (rc) { - printk(KERN_ERR "Error opening lower persistent file " - "for lower_dentry [0x%p] and lower_mnt [0x%p]; " - "rc = [%d]\n", lower_dentry, lower_mnt, rc); - inode_info->lower_file = NULL; - } +int ecryptfs_get_lower_file(struct dentry *dentry) +{ + struct ecryptfs_inode_info *inode_info = + ecryptfs_inode_to_private(dentry->d_inode); + int count, rc = 0; + + mutex_lock(&inode_info->lower_file_mutex); + count = atomic_inc_return(&inode_info->lower_file_count); + if (WARN_ON_ONCE(count < 1)) + rc = -EINVAL; + else if (count == 1) { + rc = ecryptfs_init_lower_file(dentry, + &inode_info->lower_file); + if (rc) + atomic_set(&inode_info->lower_file_count, 0); } + mutex_unlock(&inode_info->lower_file_mutex); return rc; } +void ecryptfs_put_lower_file(struct inode *inode) +{ + struct ecryptfs_inode_info *inode_info; + + inode_info = ecryptfs_inode_to_private(inode); + if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count, + &inode_info->lower_file_mutex)) { + fput(inode_info->lower_file); + inode_info->lower_file = NULL; + mutex_unlock(&inode_info->lower_file_mutex); + } +} + static struct inode *ecryptfs_get_inode(struct inode *lower_inode, struct super_block *sb) { diff --git a/fs/ecryptfs/super.c b/fs/ecryptfs/super.c index bacc882..245b517 100644 --- a/fs/ecryptfs/super.c +++ b/fs/ecryptfs/super.c @@ -55,6 +55,8 @@ static struct inode *ecryptfs_alloc_inode(struct super_block *sb) if (unlikely(!inode_info)) goto out; ecryptfs_init_crypt_stat(&inode_info->crypt_stat); + mutex_init(&inode_info->lower_file_mutex); + atomic_set(&inode_info->lower_file_count, 0); inode_info->lower_file = NULL; inode = &inode_info->vfs_inode; out: @@ -77,8 +79,7 @@ static void ecryptfs_i_callback(struct rcu_head *head) * * This is used during the final destruction of the inode. All * allocation of memory related to the inode, including allocated - * memory in the crypt_stat struct, will be released here. This - * function also fput()'s the persistent file for the lower inode. + * memory in the crypt_stat struct, will be released here. * There should be no chance that this deallocation will be missed. */ static void ecryptfs_destroy_inode(struct inode *inode) @@ -86,16 +87,7 @@ static void ecryptfs_destroy_inode(struct inode *inode) struct ecryptfs_inode_info *inode_info; inode_info = ecryptfs_inode_to_private(inode); - if (inode_info->lower_file) { - struct dentry *lower_dentry = - inode_info->lower_file->f_dentry; - - BUG_ON(!lower_dentry); - if (lower_dentry->d_inode) { - fput(inode_info->lower_file); - inode_info->lower_file = NULL; - } - } + BUG_ON(inode_info->lower_file); ecryptfs_destroy_crypt_stat(&inode_info->crypt_stat); call_rcu(&inode->i_rcu, ecryptfs_i_callback); } |
