From 2ed92554abc5c40d4450f9869c9565a1919a9242 Mon Sep 17 00:00:00 2001 From: Michael Halcrow Date: Tue, 16 Oct 2007 01:28:10 -0700 Subject: [PATCH] eCryptfs: make open, truncate, and setattr use persistent file Rather than open a new lower file for every eCryptfs file that is opened, truncated, or setattr'd, instead use the existing lower persistent file for the eCryptfs inode. Change truncate to use read_write.c functions. Change ecryptfs_getxattr() to use the common ecryptfs_getxattr_lower() function. Signed-off-by: Michael Halcrow Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/crypto.c | 2 +- fs/ecryptfs/file.c | 50 ++++--------------- fs/ecryptfs/inode.c | 113 +++++++++++++------------------------------ 3 files changed, 44 insertions(+), 121 deletions(-) diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index 55110ffe9e..26070d69e5 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -1673,7 +1673,7 @@ out: /** * ecryptfs_read_xattr_region * @page_virt: The vitual address into which to read the xattr data - * @ecryptfs_dentry: The eCryptfs dentry + * @ecryptfs_inode: The eCryptfs inode * * Attempts to read the crypto metadata from the extended attribute * region of the lower file. diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index df70bfa176..95be9a90c5 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -187,11 +187,7 @@ static int ecryptfs_open(struct inode *inode, struct file *file) /* Private value of ecryptfs_dentry allocated in * ecryptfs_lookup() */ struct dentry *lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); - struct inode *lower_inode = NULL; - struct file *lower_file = NULL; - struct vfsmount *lower_mnt; struct ecryptfs_file_info *file_info; - int lower_flags; mount_crypt_stat = &ecryptfs_superblock_to_private( ecryptfs_dentry->d_sb)->mount_crypt_stat; @@ -219,26 +215,12 @@ static int ecryptfs_open(struct inode *inode, struct file *file) if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) { ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n"); /* Policy code enabled in future release */ - crypt_stat->flags |= ECRYPTFS_POLICY_APPLIED; - crypt_stat->flags |= ECRYPTFS_ENCRYPTED; + crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED + | ECRYPTFS_ENCRYPTED); } mutex_unlock(&crypt_stat->cs_mutex); - lower_flags = file->f_flags; - if ((lower_flags & O_ACCMODE) == O_WRONLY) - lower_flags = (lower_flags & O_ACCMODE) | O_RDWR; - if (file->f_flags & O_APPEND) - lower_flags &= ~O_APPEND; - lower_mnt = ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry); - /* Corresponding fput() in ecryptfs_release() */ - rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt, - lower_flags); - if (rc) { - ecryptfs_printk(KERN_ERR, "Error opening lower file\n"); - goto out_puts; - } - ecryptfs_set_file_lower(file, lower_file); - /* Isn't this check the same as the one in lookup? */ - lower_inode = lower_dentry->d_inode; + ecryptfs_set_file_lower( + file, ecryptfs_inode_to_private(inode)->lower_file); if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) { ecryptfs_printk(KERN_DEBUG, "This is a directory\n"); crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); @@ -260,7 +242,7 @@ static int ecryptfs_open(struct inode *inode, struct file *file) "and plaintext passthrough mode is not " "enabled; returning -EIO\n"); mutex_unlock(&crypt_stat->cs_mutex); - goto out_puts; + goto out_free; } rc = 0; crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); @@ -272,11 +254,8 @@ static int ecryptfs_open(struct inode *inode, struct file *file) ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = [0x%.16x] " "size: [0x%.16x]\n", inode, inode->i_ino, i_size_read(inode)); - ecryptfs_set_file_lower(file, lower_file); goto out; -out_puts: - mntput(lower_mnt); - dput(lower_dentry); +out_free: kmem_cache_free(ecryptfs_file_info_cache, ecryptfs_file_to_private(file)); out: @@ -296,20 +275,9 @@ static int ecryptfs_flush(struct file *file, fl_owner_t td) static int ecryptfs_release(struct inode *inode, struct file *file) { - struct file *lower_file = ecryptfs_file_to_lower(file); - struct ecryptfs_file_info *file_info = ecryptfs_file_to_private(file); - struct inode *lower_inode = ecryptfs_inode_to_lower(inode); - int rc; - - rc = ecryptfs_close_lower_file(lower_file); - if (rc) { - printk(KERN_ERR "Error closing lower_file\n"); - goto out; - } - inode->i_blocks = lower_inode->i_blocks; - kmem_cache_free(ecryptfs_file_info_cache, file_info); -out: - return rc; + kmem_cache_free(ecryptfs_file_info_cache, + ecryptfs_file_to_private(file)); + return 0; } static int diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index a29dc31965..5701f816fa 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -739,8 +739,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) int rc = 0; struct inode *inode = dentry->d_inode; struct dentry *lower_dentry; - struct vfsmount *lower_mnt; - struct file fake_ecryptfs_file, *lower_file = NULL; + struct file fake_ecryptfs_file; struct ecryptfs_crypt_stat *crypt_stat; loff_t i_size = i_size_read(inode); loff_t lower_size_before_truncate; @@ -763,51 +762,43 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) goto out; } lower_dentry = ecryptfs_dentry_to_lower(dentry); - /* This dget & mntget is released through fput at out_fput: */ - lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); - rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt, - O_RDWR); - if (rc) { - ecryptfs_printk(KERN_ERR, - "Error opening dentry; rc = [%i]\n", rc); - goto out_free; - } - ecryptfs_set_file_lower(&fake_ecryptfs_file, lower_file); + ecryptfs_set_file_lower( + &fake_ecryptfs_file, + ecryptfs_inode_to_private(dentry->d_inode)->lower_file); /* Switch on growing or shrinking file */ if (new_length > i_size) { - rc = ecryptfs_fill_zeros(&fake_ecryptfs_file, new_length); - if (rc) { - ecryptfs_printk(KERN_ERR, - "Problem with fill_zeros\n"); - goto out_fput; - } - i_size_write(inode, new_length); - rc = ecryptfs_write_inode_size_to_metadata(inode); - if (rc) { - printk(KERN_ERR "Problem with " - "ecryptfs_write_inode_size_to_metadata; " - "rc = [%d]\n", rc); - goto out_fput; - } + char zero[] = { 0x00 }; + + /* Write a single 0 at the last position of the file; + * this triggers code that will fill in 0's throughout + * the intermediate portion of the previous end of the + * file and the new and of the file */ + rc = ecryptfs_write(&fake_ecryptfs_file, zero, + (new_length - 1), 1); } else { /* new_length < i_size_read(inode) */ - pgoff_t index = 0; - int end_pos_in_page = -1; - - if (new_length != 0) { - index = ((new_length - 1) >> PAGE_CACHE_SHIFT); - end_pos_in_page = ((new_length - 1) & ~PAGE_CACHE_MASK); - } - if (end_pos_in_page != (PAGE_CACHE_SIZE - 1)) { - rc = ecryptfs_write_zeros(&fake_ecryptfs_file, - index, - (end_pos_in_page + 1), - ((PAGE_CACHE_SIZE - 1) - - end_pos_in_page)); + /* We're chopping off all the pages down do the page + * in which new_length is located. Fill in the end of + * that page from (new_length & ~PAGE_CACHE_MASK) to + * PAGE_CACHE_SIZE with zeros. */ + size_t num_zeros = (PAGE_CACHE_SIZE + - (new_length & ~PAGE_CACHE_MASK)); + + if (num_zeros) { + char *zeros_virt; + + zeros_virt = kzalloc(num_zeros, GFP_KERNEL); + if (!zeros_virt) { + rc = -ENOMEM; + goto out_free; + } + rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt, + new_length, num_zeros); + kfree(zeros_virt); if (rc) { printk(KERN_ERR "Error attempting to zero out " "the remainder of the end page on " "reducing truncate; rc = [%d]\n", rc); - goto out_fput; + goto out_free; } } vmtruncate(inode, new_length); @@ -816,7 +807,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) printk(KERN_ERR "Problem with " "ecryptfs_write_inode_size_to_metadata; " "rc = [%d]\n", rc); - goto out_fput; + goto out_free; } /* We are reducing the size of the ecryptfs file, and need to * know if we need to reduce the size of the lower file. */ @@ -828,14 +819,6 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) vmtruncate(lower_dentry->d_inode, lower_size_after_truncate); } - /* Update the access times */ - lower_dentry->d_inode->i_mtime = lower_dentry->d_inode->i_ctime - = CURRENT_TIME; - mark_inode_dirty_sync(inode); -out_fput: - rc = ecryptfs_close_lower_file(lower_file); - if (rc) - printk(KERN_ERR "Error closing lower_file\n"); out_free: if (ecryptfs_file_to_private(&fake_ecryptfs_file)) kmem_cache_free(ecryptfs_file_info_cache, @@ -895,21 +878,8 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) else if (S_ISREG(dentry->d_inode->i_mode) && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED) || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) { - struct vfsmount *lower_mnt; - struct file *lower_file = NULL; struct ecryptfs_mount_crypt_stat *mount_crypt_stat; - int lower_flags; - lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); - lower_flags = O_RDONLY; - rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, - lower_mnt, lower_flags); - if (rc) { - printk(KERN_ERR - "Error opening lower file; rc = [%d]\n", rc); - mutex_unlock(&crypt_stat->cs_mutex); - goto out; - } mount_crypt_stat = &ecryptfs_superblock_to_private( dentry->d_sb)->mount_crypt_stat; rc = ecryptfs_read_metadata(dentry); @@ -923,16 +893,13 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) "enabled; returning -EIO\n"); mutex_unlock(&crypt_stat->cs_mutex); - fput(lower_file); goto out; } rc = 0; crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); mutex_unlock(&crypt_stat->cs_mutex); - fput(lower_file); goto out; } - fput(lower_file); } mutex_unlock(&crypt_stat->cs_mutex); if (ia->ia_valid & ATTR_SIZE) { @@ -995,20 +962,8 @@ ssize_t ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size) { - int rc = 0; - struct dentry *lower_dentry; - - lower_dentry = ecryptfs_dentry_to_lower(dentry); - if (!lower_dentry->d_inode->i_op->getxattr) { - rc = -ENOSYS; - goto out; - } - mutex_lock(&lower_dentry->d_inode->i_mutex); - rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value, - size); - mutex_unlock(&lower_dentry->d_inode->i_mutex); -out: - return rc; + return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name, + value, size); } static ssize_t -- 2.39.5