diff options
| -rw-r--r-- | fs/ecryptfs/inode.c | 115 |
1 files changed, 60 insertions, 55 deletions
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 81cf42d01ec5..695573850569 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -725,83 +725,88 @@ upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat, static int truncate_upper(struct dentry *dentry, struct iattr *ia, struct iattr *lower_ia) { - int rc = 0; struct inode *inode = d_inode(dentry); struct ecryptfs_crypt_stat *crypt_stat; loff_t i_size = i_size_read(inode); loff_t lower_size_before_truncate; loff_t lower_size_after_truncate; + size_t num_zeros; + int rc; if (unlikely((ia->ia_size == i_size))) { lower_ia->ia_valid &= ~ATTR_SIZE; return 0; } + rc = ecryptfs_get_lower_file(dentry, inode); if (rc) return rc; - crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat; - /* Switch on growing or shrinking file */ + if (ia->ia_size > i_size) { 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 end of the file. + */ + rc = ecryptfs_write(inode, zero, ia->ia_size - 1, 1); lower_ia->ia_valid &= ~ATTR_SIZE; - /* 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(inode, zero, - (ia->ia_size - 1), 1); - } else { /* ia->ia_size < i_size_read(inode) */ - /* We're chopping off all the pages down to the page - * in which ia->ia_size is located. Fill in the end of - * that page from (ia->ia_size & ~PAGE_MASK) to - * PAGE_SIZE with zeros. */ - size_t num_zeros = (PAGE_SIZE - - (ia->ia_size & ~PAGE_MASK)); - - if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { - truncate_setsize(inode, ia->ia_size); - lower_ia->ia_size = ia->ia_size; - lower_ia->ia_valid |= ATTR_SIZE; - goto out; - } - if (num_zeros) { - char *zeros_virt; + goto out; + } - zeros_virt = kzalloc(num_zeros, GFP_KERNEL); - if (!zeros_virt) { - rc = -ENOMEM; - goto out; - } - rc = ecryptfs_write(inode, zeros_virt, - ia->ia_size, 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; - } - } + crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat; + if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { truncate_setsize(inode, ia->ia_size); - rc = ecryptfs_write_inode_size_to_metadata(inode); + lower_ia->ia_size = ia->ia_size; + lower_ia->ia_valid |= ATTR_SIZE; + goto out; + } + + /* + * We're chopping off all the pages down to the page in which + * ia->ia_size is located. Fill in the end of that page from + * (ia->ia_size & ~PAGE_MASK) to PAGE_SIZE with zeros. + */ + num_zeros = PAGE_SIZE - (ia->ia_size & ~PAGE_MASK); + if (num_zeros) { + char *zeros_virt; + + zeros_virt = kzalloc(num_zeros, GFP_KERNEL); + if (!zeros_virt) { + rc = -ENOMEM; + goto out; + } + rc = ecryptfs_write(inode, zeros_virt, ia->ia_size, num_zeros); + kfree(zeros_virt); if (rc) { - printk(KERN_ERR "Problem with " - "ecryptfs_write_inode_size_to_metadata; " - "rc = [%d]\n", rc); + pr_err("Error attempting to zero out the remainder of the end page on reducing truncate; rc = [%d]\n", + rc); goto out; } - /* 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 = - upper_size_to_lower_size(crypt_stat, i_size); - lower_size_after_truncate = - upper_size_to_lower_size(crypt_stat, ia->ia_size); - if (lower_size_after_truncate < lower_size_before_truncate) { - lower_ia->ia_size = lower_size_after_truncate; - lower_ia->ia_valid |= ATTR_SIZE; - } else - lower_ia->ia_valid &= ~ATTR_SIZE; + } + truncate_setsize(inode, ia->ia_size); + rc = ecryptfs_write_inode_size_to_metadata(inode); + if (rc) { + pr_err("Problem with ecryptfs_write_inode_size_to_metadata; rc = [%d]\n", + rc); + goto out; + } + + /* + * 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 = + upper_size_to_lower_size(crypt_stat, i_size); + lower_size_after_truncate = + upper_size_to_lower_size(crypt_stat, ia->ia_size); + if (lower_size_after_truncate < lower_size_before_truncate) { + lower_ia->ia_size = lower_size_after_truncate; + lower_ia->ia_valid |= ATTR_SIZE; + } else { + lower_ia->ia_valid &= ~ATTR_SIZE; } out: ecryptfs_put_lower_file(inode); |