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 <mhalcrow@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michael Halcrow
Linus Torvalds
Родитель
d7cdc5febf
Коммит
2ed92554ab
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@ -1673,7 +1673,7 @@ out:
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/**
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* ecryptfs_read_xattr_region
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* @page_virt: The vitual address into which to read the xattr data
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* @ecryptfs_dentry: The eCryptfs dentry
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* @ecryptfs_inode: The eCryptfs inode
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*
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* Attempts to read the crypto metadata from the extended attribute
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* region of the lower file.
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@ -187,11 +187,7 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
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/* Private value of ecryptfs_dentry allocated in
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* ecryptfs_lookup() */
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struct dentry *lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
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struct inode *lower_inode = NULL;
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struct file *lower_file = NULL;
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struct vfsmount *lower_mnt;
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struct ecryptfs_file_info *file_info;
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int lower_flags;
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mount_crypt_stat = &ecryptfs_superblock_to_private(
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ecryptfs_dentry->d_sb)->mount_crypt_stat;
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@ -219,26 +215,12 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
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if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) {
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ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n");
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/* Policy code enabled in future release */
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crypt_stat->flags |= ECRYPTFS_POLICY_APPLIED;
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crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
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crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED
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| ECRYPTFS_ENCRYPTED);
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}
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mutex_unlock(&crypt_stat->cs_mutex);
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lower_flags = file->f_flags;
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if ((lower_flags & O_ACCMODE) == O_WRONLY)
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lower_flags = (lower_flags & O_ACCMODE) | O_RDWR;
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if (file->f_flags & O_APPEND)
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lower_flags &= ~O_APPEND;
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lower_mnt = ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
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/* Corresponding fput() in ecryptfs_release() */
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rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt,
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lower_flags);
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if (rc) {
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ecryptfs_printk(KERN_ERR, "Error opening lower file\n");
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goto out_puts;
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}
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ecryptfs_set_file_lower(file, lower_file);
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/* Isn't this check the same as the one in lookup? */
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lower_inode = lower_dentry->d_inode;
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ecryptfs_set_file_lower(
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file, ecryptfs_inode_to_private(inode)->lower_file);
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if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
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ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
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crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
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@ -260,7 +242,7 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
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"and plaintext passthrough mode is not "
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"enabled; returning -EIO\n");
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mutex_unlock(&crypt_stat->cs_mutex);
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goto out_puts;
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goto out_free;
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}
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rc = 0;
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crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
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@ -272,11 +254,8 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
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ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = [0x%.16x] "
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"size: [0x%.16x]\n", inode, inode->i_ino,
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i_size_read(inode));
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ecryptfs_set_file_lower(file, lower_file);
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goto out;
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out_puts:
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mntput(lower_mnt);
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dput(lower_dentry);
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out_free:
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kmem_cache_free(ecryptfs_file_info_cache,
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ecryptfs_file_to_private(file));
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out:
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@ -296,20 +275,9 @@ static int ecryptfs_flush(struct file *file, fl_owner_t td)
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static int ecryptfs_release(struct inode *inode, struct file *file)
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{
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struct file *lower_file = ecryptfs_file_to_lower(file);
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struct ecryptfs_file_info *file_info = ecryptfs_file_to_private(file);
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struct inode *lower_inode = ecryptfs_inode_to_lower(inode);
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int rc;
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rc = ecryptfs_close_lower_file(lower_file);
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if (rc) {
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printk(KERN_ERR "Error closing lower_file\n");
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goto out;
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}
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inode->i_blocks = lower_inode->i_blocks;
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kmem_cache_free(ecryptfs_file_info_cache, file_info);
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out:
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return rc;
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kmem_cache_free(ecryptfs_file_info_cache,
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ecryptfs_file_to_private(file));
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return 0;
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}
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static int
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@ -739,8 +739,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
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int rc = 0;
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struct inode *inode = dentry->d_inode;
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struct dentry *lower_dentry;
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struct vfsmount *lower_mnt;
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struct file fake_ecryptfs_file, *lower_file = NULL;
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struct file fake_ecryptfs_file;
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struct ecryptfs_crypt_stat *crypt_stat;
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loff_t i_size = i_size_read(inode);
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loff_t lower_size_before_truncate;
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@ -763,51 +762,43 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
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goto out;
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}
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lower_dentry = ecryptfs_dentry_to_lower(dentry);
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/* This dget & mntget is released through fput at out_fput: */
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lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
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rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt,
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O_RDWR);
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if (rc) {
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ecryptfs_printk(KERN_ERR,
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"Error opening dentry; rc = [%i]\n", rc);
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goto out_free;
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}
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ecryptfs_set_file_lower(&fake_ecryptfs_file, lower_file);
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ecryptfs_set_file_lower(
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&fake_ecryptfs_file,
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ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
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/* Switch on growing or shrinking file */
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if (new_length > i_size) {
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rc = ecryptfs_fill_zeros(&fake_ecryptfs_file, new_length);
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if (rc) {
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ecryptfs_printk(KERN_ERR,
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"Problem with fill_zeros\n");
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goto out_fput;
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}
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i_size_write(inode, new_length);
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rc = ecryptfs_write_inode_size_to_metadata(inode);
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if (rc) {
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printk(KERN_ERR "Problem with "
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"ecryptfs_write_inode_size_to_metadata; "
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"rc = [%d]\n", rc);
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goto out_fput;
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}
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} else { /* new_length < i_size_read(inode) */
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pgoff_t index = 0;
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int end_pos_in_page = -1;
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char zero[] = { 0x00 };
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if (new_length != 0) {
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index = ((new_length - 1) >> PAGE_CACHE_SHIFT);
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end_pos_in_page = ((new_length - 1) & ~PAGE_CACHE_MASK);
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}
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if (end_pos_in_page != (PAGE_CACHE_SIZE - 1)) {
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rc = ecryptfs_write_zeros(&fake_ecryptfs_file,
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index,
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(end_pos_in_page + 1),
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((PAGE_CACHE_SIZE - 1)
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- end_pos_in_page));
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/* Write a single 0 at the last position of the file;
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* this triggers code that will fill in 0's throughout
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* the intermediate portion of the previous end of the
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* file and the new and of the file */
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rc = ecryptfs_write(&fake_ecryptfs_file, zero,
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(new_length - 1), 1);
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} else { /* new_length < i_size_read(inode) */
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/* We're chopping off all the pages down do the page
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* in which new_length is located. Fill in the end of
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* that page from (new_length & ~PAGE_CACHE_MASK) to
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* PAGE_CACHE_SIZE with zeros. */
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size_t num_zeros = (PAGE_CACHE_SIZE
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- (new_length & ~PAGE_CACHE_MASK));
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if (num_zeros) {
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char *zeros_virt;
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zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
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if (!zeros_virt) {
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rc = -ENOMEM;
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goto out_free;
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}
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rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
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new_length, num_zeros);
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kfree(zeros_virt);
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if (rc) {
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printk(KERN_ERR "Error attempting to zero out "
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"the remainder of the end page on "
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"reducing truncate; rc = [%d]\n", rc);
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goto out_fput;
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goto out_free;
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}
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}
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vmtruncate(inode, new_length);
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@ -816,7 +807,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
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printk(KERN_ERR "Problem with "
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"ecryptfs_write_inode_size_to_metadata; "
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"rc = [%d]\n", rc);
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goto out_fput;
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goto out_free;
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}
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/* We are reducing the size of the ecryptfs file, and need to
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* know if we need to reduce the size of the lower file. */
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@ -828,14 +819,6 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
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vmtruncate(lower_dentry->d_inode,
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lower_size_after_truncate);
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}
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/* Update the access times */
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lower_dentry->d_inode->i_mtime = lower_dentry->d_inode->i_ctime
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= CURRENT_TIME;
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mark_inode_dirty_sync(inode);
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out_fput:
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rc = ecryptfs_close_lower_file(lower_file);
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if (rc)
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printk(KERN_ERR "Error closing lower_file\n");
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out_free:
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if (ecryptfs_file_to_private(&fake_ecryptfs_file))
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kmem_cache_free(ecryptfs_file_info_cache,
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@ -895,21 +878,8 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
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else if (S_ISREG(dentry->d_inode->i_mode)
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&& (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
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|| !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
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struct vfsmount *lower_mnt;
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struct file *lower_file = NULL;
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struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
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int lower_flags;
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lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
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lower_flags = O_RDONLY;
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rc = ecryptfs_open_lower_file(&lower_file, lower_dentry,
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lower_mnt, lower_flags);
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if (rc) {
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printk(KERN_ERR
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"Error opening lower file; rc = [%d]\n", rc);
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mutex_unlock(&crypt_stat->cs_mutex);
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goto out;
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}
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mount_crypt_stat = &ecryptfs_superblock_to_private(
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dentry->d_sb)->mount_crypt_stat;
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rc = ecryptfs_read_metadata(dentry);
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@ -923,16 +893,13 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
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"enabled; returning -EIO\n");
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mutex_unlock(&crypt_stat->cs_mutex);
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fput(lower_file);
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goto out;
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}
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rc = 0;
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crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
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mutex_unlock(&crypt_stat->cs_mutex);
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fput(lower_file);
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goto out;
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}
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fput(lower_file);
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}
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mutex_unlock(&crypt_stat->cs_mutex);
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if (ia->ia_valid & ATTR_SIZE) {
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@ -995,20 +962,8 @@ ssize_t
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ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
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size_t size)
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{
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int rc = 0;
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struct dentry *lower_dentry;
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lower_dentry = ecryptfs_dentry_to_lower(dentry);
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if (!lower_dentry->d_inode->i_op->getxattr) {
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rc = -ENOSYS;
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goto out;
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}
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mutex_lock(&lower_dentry->d_inode->i_mutex);
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rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
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size);
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mutex_unlock(&lower_dentry->d_inode->i_mutex);
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out:
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return rc;
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return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
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value, size);
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}
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static ssize_t
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