diff options
| -rw-r--r-- | fs/ecryptfs/mmap.c | 81 |
1 files changed, 50 insertions, 31 deletions
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c index 245c2dc02d5c..04d7b3fa1ac6 100644 --- a/fs/ecryptfs/mmap.c +++ b/fs/ecryptfs/mmap.c @@ -265,22 +265,34 @@ out: } /** - * ecryptfs_prepare_write + * ecryptfs_write_begin * @file: The eCryptfs file - * @page: The eCryptfs page - * @from: The start byte from which we will write - * @to: The end byte to which we will write + * @mapping: The eCryptfs object + * @pos: The file offset at which to start writing + * @len: Length of the write + * @flags: Various flags + * @pagep: Pointer to return the page + * @fsdata: Pointer to return fs data (unused) * * This function must zero any hole we create * * Returns zero on success; non-zero otherwise */ -static int ecryptfs_prepare_write(struct file *file, struct page *page, - unsigned from, unsigned to) +static int ecryptfs_write_begin(struct file *file, + struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata) { + pgoff_t index = pos >> PAGE_CACHE_SHIFT; + struct page *page; loff_t prev_page_end_size; int rc = 0; + page = __grab_cache_page(mapping, index); + if (!page) + return -ENOMEM; + *pagep = page; + if (!PageUptodate(page)) { struct ecryptfs_crypt_stat *crypt_stat = &ecryptfs_inode_to_private( @@ -289,8 +301,7 @@ static int ecryptfs_prepare_write(struct file *file, struct page *page, if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED) || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) { rc = ecryptfs_read_lower_page_segment( - page, page->index, 0, PAGE_CACHE_SIZE, - page->mapping->host); + page, index, 0, PAGE_CACHE_SIZE, mapping->host); if (rc) { printk(KERN_ERR "%s: Error attemping to read " "lower page segment; rc = [%d]\n", @@ -316,8 +327,8 @@ static int ecryptfs_prepare_write(struct file *file, struct page *page, SetPageUptodate(page); } else { rc = ecryptfs_read_lower_page_segment( - page, page->index, 0, PAGE_CACHE_SIZE, - page->mapping->host); + page, index, 0, PAGE_CACHE_SIZE, + mapping->host); if (rc) { printk(KERN_ERR "%s: Error reading " "page; rc = [%d]\n", @@ -339,10 +350,10 @@ static int ecryptfs_prepare_write(struct file *file, struct page *page, SetPageUptodate(page); } } - prev_page_end_size = ((loff_t)page->index << PAGE_CACHE_SHIFT); + prev_page_end_size = ((loff_t)index << PAGE_CACHE_SHIFT); /* If creating a page or more of holes, zero them out via truncate. * Note, this will increase i_size. */ - if (page->index != 0) { + if (index != 0) { if (prev_page_end_size > i_size_read(page->mapping->host)) { rc = ecryptfs_truncate(file->f_path.dentry, prev_page_end_size); @@ -357,8 +368,8 @@ static int ecryptfs_prepare_write(struct file *file, struct page *page, } /* Writing to a new page, and creating a small hole from start * of page? Zero it out. */ - if ((i_size_read(page->mapping->host) == prev_page_end_size) - && (from != 0)) + if ((i_size_read(mapping->host) == prev_page_end_size) + && (pos != 0)) zero_user(page, 0, PAGE_CACHE_SIZE); out: return rc; @@ -445,21 +456,28 @@ int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode) } /** - * ecryptfs_commit_write + * ecryptfs_write_end * @file: The eCryptfs file object + * @mapping: The eCryptfs object + * @pos: The file position + * @len: The length of the data (unused) + * @copied: The amount of data copied * @page: The eCryptfs page - * @from: Ignored (we rotate the page IV on each write) - * @to: Ignored + * @fsdata: The fsdata (unused) * * This is where we encrypt the data and pass the encrypted data to * the lower filesystem. In OpenPGP-compatible mode, we operate on * entire underlying packets. */ -static int ecryptfs_commit_write(struct file *file, struct page *page, - unsigned from, unsigned to) +static int ecryptfs_write_end(struct file *file, + struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata) { - loff_t pos; - struct inode *ecryptfs_inode = page->mapping->host; + pgoff_t index = pos >> PAGE_CACHE_SHIFT; + unsigned from = pos & (PAGE_CACHE_SIZE - 1); + unsigned to = from + copied; + struct inode *ecryptfs_inode = mapping->host; struct ecryptfs_crypt_stat *crypt_stat = &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)->crypt_stat; int rc; @@ -471,25 +489,22 @@ static int ecryptfs_commit_write(struct file *file, struct page *page, } else ecryptfs_printk(KERN_DEBUG, "Not a new file\n"); ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page" - "(page w/ index = [0x%.16x], to = [%d])\n", page->index, - to); + "(page w/ index = [0x%.16x], to = [%d])\n", index, to); /* Fills in zeros if 'to' goes beyond inode size */ rc = fill_zeros_to_end_of_page(page, to); if (rc) { ecryptfs_printk(KERN_WARNING, "Error attempting to fill " - "zeros in page with index = [0x%.16x]\n", - page->index); + "zeros in page with index = [0x%.16x]\n", index); goto out; } rc = ecryptfs_encrypt_page(page); if (rc) { ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper " - "index [0x%.16x])\n", page->index); + "index [0x%.16x])\n", index); goto out; } - pos = (((loff_t)page->index) << PAGE_CACHE_SHIFT) + to; - if (pos > i_size_read(ecryptfs_inode)) { - i_size_write(ecryptfs_inode, pos); + if (pos + copied > i_size_read(ecryptfs_inode)) { + i_size_write(ecryptfs_inode, pos + copied); ecryptfs_printk(KERN_DEBUG, "Expanded file size to " "[0x%.16x]\n", i_size_read(ecryptfs_inode)); } @@ -497,7 +512,11 @@ static int ecryptfs_commit_write(struct file *file, struct page *page, if (rc) printk(KERN_ERR "Error writing inode size to metadata; " "rc = [%d]\n", rc); + else + rc = copied; out: + unlock_page(page); + page_cache_release(page); return rc; } @@ -518,7 +537,7 @@ static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block) struct address_space_operations ecryptfs_aops = { .writepage = ecryptfs_writepage, .readpage = ecryptfs_readpage, - .prepare_write = ecryptfs_prepare_write, - .commit_write = ecryptfs_commit_write, + .write_begin = ecryptfs_write_begin, + .write_end = ecryptfs_write_end, .bmap = ecryptfs_bmap, }; |
