From d7cdc5febf9f2664755002c3a2f84bd348389fe9 Mon Sep 17 00:00:00 2001 From: Michael Halcrow Date: Tue, 16 Oct 2007 01:28:10 -0700 Subject: eCryptfs: update metadata read/write functions Update the metadata read/write functions and grow_file() to use the read_write.c routines. Do not open another lower file; use the persistent lower file instead. Provide a separate function for crypto.c::ecryptfs_read_xattr_region() to get to the lower xattr without having to go through the eCryptfs getxattr. Signed-off-by: Michael Halcrow Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/crypto.c | 127 ++++++++++++++++++++++++--------------------------- 1 file changed, 59 insertions(+), 68 deletions(-) (limited to 'fs/ecryptfs/crypto.c') diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index 7f788ea5da2..55110ffe9eb 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -1342,21 +1342,28 @@ out: return rc; } -int ecryptfs_read_and_validate_header_region(char *data, struct dentry *dentry, - struct vfsmount *mnt) +int ecryptfs_read_and_validate_header_region(char *data, + struct inode *ecryptfs_inode) { + struct ecryptfs_crypt_stat *crypt_stat = + &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); int rc; - rc = ecryptfs_read_header_region(data, dentry, mnt); - if (rc) + rc = ecryptfs_read_lower(data, 0, crypt_stat->extent_size, + ecryptfs_inode); + if (rc) { + printk(KERN_ERR "%s: Error reading header region; rc = [%d]\n", + __FUNCTION__, rc); goto out; - if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) + } + if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) { rc = -EINVAL; + ecryptfs_printk(KERN_DEBUG, "Valid marker not found\n"); + } out: return rc; } - void ecryptfs_write_header_metadata(char *virt, struct ecryptfs_crypt_stat *crypt_stat, @@ -1441,24 +1448,19 @@ static int ecryptfs_write_headers_virt(char *page_virt, size_t *size, static int ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat, - struct file *lower_file, char *page_virt) + struct dentry *ecryptfs_dentry, + char *page_virt) { - mm_segment_t oldfs; int current_header_page; int header_pages; - ssize_t size; - int rc = 0; + int rc; - lower_file->f_pos = 0; - oldfs = get_fs(); - set_fs(get_ds()); - size = vfs_write(lower_file, (char __user *)page_virt, PAGE_CACHE_SIZE, - &lower_file->f_pos); - if (size < 0) { - rc = (int)size; - printk(KERN_ERR "Error attempting to write lower page; " - "rc = [%d]\n", rc); - set_fs(oldfs); + rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, page_virt, + 0, PAGE_CACHE_SIZE); + if (rc) { + printk(KERN_ERR "%s: Error attempting to write header " + "information to lower file; rc = [%d]\n", __FUNCTION__, + rc); goto out; } header_pages = ((crypt_stat->extent_size @@ -1467,18 +1469,19 @@ ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat, memset(page_virt, 0, PAGE_CACHE_SIZE); current_header_page = 1; while (current_header_page < header_pages) { - size = vfs_write(lower_file, (char __user *)page_virt, - PAGE_CACHE_SIZE, &lower_file->f_pos); - if (size < 0) { - rc = (int)size; - printk(KERN_ERR "Error attempting to write lower page; " - "rc = [%d]\n", rc); - set_fs(oldfs); + loff_t offset; + + offset = (current_header_page << PAGE_CACHE_SHIFT); + if ((rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, + page_virt, offset, + PAGE_CACHE_SIZE))) { + printk(KERN_ERR "%s: Error attempting to write header " + "information to lower file; rc = [%d]\n", + __FUNCTION__, rc); goto out; } current_header_page++; } - set_fs(oldfs); out: return rc; } @@ -1498,7 +1501,6 @@ ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, /** * ecryptfs_write_metadata * @ecryptfs_dentry: The eCryptfs dentry - * @lower_file: The lower file struct, which was returned from dentry_open * * Write the file headers out. This will likely involve a userspace * callout, in which the session key is encrypted with one or more @@ -1506,22 +1508,21 @@ ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, * retrieved via a prompt. Exactly what happens at this point should * be policy-dependent. * + * TODO: Support header information spanning multiple pages + * * Returns zero on success; non-zero on error */ -int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry, - struct file *lower_file) +int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry) { - struct ecryptfs_crypt_stat *crypt_stat; + struct ecryptfs_crypt_stat *crypt_stat = + &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; char *page_virt; - size_t size; + size_t size = 0; int rc = 0; - crypt_stat = &ecryptfs_inode_to_private( - ecryptfs_dentry->d_inode)->crypt_stat; if (likely(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { - ecryptfs_printk(KERN_DEBUG, "Key is " - "invalid; bailing out\n"); + printk(KERN_ERR "Key is invalid; bailing out\n"); rc = -EINVAL; goto out; } @@ -1550,7 +1551,8 @@ int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry, crypt_stat, page_virt, size); else - rc = ecryptfs_write_metadata_to_contents(crypt_stat, lower_file, + rc = ecryptfs_write_metadata_to_contents(crypt_stat, + ecryptfs_dentry, page_virt); if (rc) { printk(KERN_ERR "Error writing metadata out to lower file; " @@ -1678,15 +1680,17 @@ out: * * Returns zero on success; non-zero on error */ -int ecryptfs_read_xattr_region(char *page_virt, struct dentry *ecryptfs_dentry) +int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode) { + struct dentry *lower_dentry = + ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry; ssize_t size; int rc = 0; - size = ecryptfs_getxattr(ecryptfs_dentry, ECRYPTFS_XATTR_NAME, - page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE); + size = ecryptfs_getxattr_lower(lower_dentry, ECRYPTFS_XATTR_NAME, + page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE); if (size < 0) { - printk(KERN_DEBUG "Error attempting to read the [%s] " + printk(KERN_ERR "Error attempting to read the [%s] " "xattr from the lower file; return value = [%zd]\n", ECRYPTFS_XATTR_NAME, size); rc = -EINVAL; @@ -1701,7 +1705,7 @@ int ecryptfs_read_and_validate_xattr_region(char *page_virt, { int rc; - rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry); + rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry->d_inode); if (rc) goto out; if (!contains_ecryptfs_marker(page_virt + ECRYPTFS_FILE_SIZE_BYTES)) { @@ -1715,8 +1719,6 @@ out: /** * ecryptfs_read_metadata - * @ecryptfs_dentry: The eCryptfs dentry - * @lower_file: The lower file from which to read the metadata * * Common entry point for reading file metadata. From here, we could * retrieve the header information from the header region of the file, @@ -1727,15 +1729,13 @@ out: * * Returns zero if valid headers found and parsed; non-zero otherwise */ -int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry, - struct file *lower_file) +int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry) { int rc = 0; char *page_virt = NULL; - mm_segment_t oldfs; - ssize_t bytes_read; + struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode; struct ecryptfs_crypt_stat *crypt_stat = - &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; + &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; struct ecryptfs_mount_crypt_stat *mount_crypt_stat = &ecryptfs_superblock_to_private( ecryptfs_dentry->d_sb)->mount_crypt_stat; @@ -1746,27 +1746,18 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry, page_virt = kmem_cache_alloc(ecryptfs_header_cache_1, GFP_USER); if (!page_virt) { rc = -ENOMEM; - ecryptfs_printk(KERN_ERR, "Unable to allocate page_virt\n"); + printk(KERN_ERR "%s: Unable to allocate page_virt\n", + __FUNCTION__); goto out; } - lower_file->f_pos = 0; - oldfs = get_fs(); - set_fs(get_ds()); - bytes_read = lower_file->f_op->read(lower_file, - (char __user *)page_virt, - ECRYPTFS_DEFAULT_EXTENT_SIZE, - &lower_file->f_pos); - set_fs(oldfs); - if (bytes_read != ECRYPTFS_DEFAULT_EXTENT_SIZE) { - rc = -EINVAL; - goto out; - } - rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, - ecryptfs_dentry, - ECRYPTFS_VALIDATE_HEADER_SIZE); + rc = ecryptfs_read_lower(page_virt, 0, crypt_stat->extent_size, + ecryptfs_inode); + if (!rc) + rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, + ecryptfs_dentry, + ECRYPTFS_VALIDATE_HEADER_SIZE); if (rc) { - rc = ecryptfs_read_xattr_region(page_virt, - ecryptfs_dentry); + rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode); if (rc) { printk(KERN_DEBUG "Valid eCryptfs headers not found in " "file header region or xattr region\n"); -- cgit v1.2.3