From dd2a3b7ad98f8482cae481cad89dfed5eee48365 Mon Sep 17 00:00:00 2001 From: Michael Halcrow Date: Mon, 12 Feb 2007 00:53:46 -0800 Subject: [PATCH] eCryptfs: Generalize metadata read/write Generalize the metadata reading and writing mechanisms, with two targets for now: metadata in file header and metadata in the user.ecryptfs xattr of the lower file. [akpm@osdl.org: printk warning fix] [bunk@stusta.de: make some needlessly global code static] Signed-off-by: Michael Halcrow Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/inode.c | 61 ++++++++++++++++++++++++++++++----------------------- 1 file changed, 35 insertions(+), 26 deletions(-) (limited to 'fs/ecryptfs/inode.c') diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index d4f02f3e18d..6b45b2908f1 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -3,7 +3,7 @@ * * Copyright (C) 1997-2004 Erez Zadok * Copyright (C) 2001-2004 Stony Brook University - * Copyright (C) 2004-2006 International Business Machines Corp. + * Copyright (C) 2004-2007 International Business Machines Corp. * Author(s): Michael A. Halcrow * Michael C. Thompsion * @@ -169,7 +169,9 @@ static int grow_file(struct dentry *ecryptfs_dentry, struct file *lower_file, goto out; } i_size_write(inode, 0); - ecryptfs_write_inode_size_to_header(lower_file, lower_inode, inode); + ecryptfs_write_inode_size_to_metadata(lower_file, lower_inode, inode, + ecryptfs_dentry, + ECRYPTFS_LOWER_I_MUTEX_NOT_HELD); ECRYPTFS_SET_FLAG(ecryptfs_inode_to_private(inode)->crypt_stat.flags, ECRYPTFS_NEW_FILE); out: @@ -225,7 +227,7 @@ static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry) "context\n"); goto out_fput; } - rc = ecryptfs_write_headers(ecryptfs_dentry, lower_file); + rc = ecryptfs_write_metadata(ecryptfs_dentry, lower_file); if (rc) { ecryptfs_printk(KERN_DEBUG, "Error writing headers\n"); goto out_fput; @@ -362,32 +364,33 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry, } /* Released in this function */ page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, - GFP_USER); + GFP_USER); if (!page_virt) { rc = -ENOMEM; ecryptfs_printk(KERN_ERR, "Cannot ecryptfs_kmalloc a page\n"); goto out_dput; } - - rc = ecryptfs_read_header_region(page_virt, lower_dentry, nd->mnt); crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED)) ecryptfs_set_default_sizes(crypt_stat); + rc = ecryptfs_read_and_validate_header_region(page_virt, lower_dentry, + nd->mnt); if (rc) { - rc = 0; - ecryptfs_printk(KERN_WARNING, "Error reading header region;" - " assuming unencrypted\n"); - } else { - if (!contains_ecryptfs_marker(page_virt - + ECRYPTFS_FILE_SIZE_BYTES)) { + rc = ecryptfs_read_and_validate_xattr_region(page_virt, dentry); + if (rc) { + printk(KERN_DEBUG "Valid metadata not found in header " + "region or xattr region; treating file as " + "unencrypted\n"); + rc = 0; kmem_cache_free(ecryptfs_header_cache_2, page_virt); goto out; } - memcpy(&file_size, page_virt, sizeof(file_size)); - file_size = be64_to_cpu(file_size); - i_size_write(dentry->d_inode, (loff_t)file_size); + crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; } + memcpy(&file_size, page_virt, sizeof(file_size)); + file_size = be64_to_cpu(file_size); + i_size_write(dentry->d_inode, (loff_t)file_size); kmem_cache_free(ecryptfs_header_cache_2, page_virt); goto out; @@ -781,20 +784,26 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) goto out_fput; } i_size_write(inode, new_length); - rc = ecryptfs_write_inode_size_to_header(lower_file, - lower_dentry->d_inode, - inode); + rc = ecryptfs_write_inode_size_to_metadata( + lower_file, lower_dentry->d_inode, inode, dentry, + ECRYPTFS_LOWER_I_MUTEX_NOT_HELD); if (rc) { - ecryptfs_printk(KERN_ERR, - "Problem with ecryptfs_write" - "_inode_size\n"); + printk(KERN_ERR "Problem with " + "ecryptfs_write_inode_size_to_metadata; " + "rc = [%d]\n", rc); goto out_fput; } } else { /* new_length < i_size_read(inode) */ vmtruncate(inode, new_length); - ecryptfs_write_inode_size_to_header(lower_file, - lower_dentry->d_inode, - inode); + rc = ecryptfs_write_inode_size_to_metadata( + lower_file, lower_dentry->d_inode, inode, dentry, + ECRYPTFS_LOWER_I_MUTEX_NOT_HELD); + if (rc) { + printk(KERN_ERR "Problem with " + "ecryptfs_write_inode_size_to_metadata; " + "rc = [%d]\n", rc); + goto out_fput; + } /* We are reducing the size of the ecryptfs file, and need to * know if we need to reduce the size of the lower file. */ lower_size_before_truncate = @@ -881,7 +890,7 @@ out: return rc; } -static int +int ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) { @@ -901,7 +910,7 @@ out: return rc; } -static ssize_t +ssize_t ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size) { -- cgit v1.2.3