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Commit 2ed92554 authored by Michael Halcrow's avatar Michael Halcrow Committed by Linus Torvalds
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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: default avatarMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d7cdc5fe

fs/ecryptfs/crypto.c

+1 −1
Original line number Diff line number Diff line
@@ -1673,7 +1673,7 @@ static int ecryptfs_read_headers_virt(char *page_virt, 
/**

 * 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.

fs/ecryptfs/file.c

+9 −41
Original line number Diff line number Diff line
@@ -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

fs/ecryptfs/inode.c

+34 −79
Original line number Diff line number Diff line
@@ -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