diff options
Diffstat (limited to 'fs/ecryptfs/main.c')
-rw-r--r-- | fs/ecryptfs/main.c | 76 |
1 files changed, 52 insertions, 24 deletions
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index c27c0ecf90bc..89b93389af8e 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) { @@ -276,7 +304,7 @@ static void ecryptfs_init_mount_crypt_stat( /** * ecryptfs_parse_options * @sb: The ecryptfs super block - * @options: The options pased to the kernel + * @options: The options passed to the kernel * * Parse mount options: * debug=N - ecryptfs_verbosity level for debug output @@ -840,7 +868,7 @@ static int __init ecryptfs_init(void) } rc = ecryptfs_init_messaging(); if (rc) { - printk(KERN_ERR "Failure occured while attempting to " + printk(KERN_ERR "Failure occurred while attempting to " "initialize the communications channel to " "ecryptfsd\n"); goto out_destroy_kthread; |