From: "Aneesh Kumar K.V" Subject: [PATCH -v2] ext4: Use page_mkwrite vma_operations to get mmap write notification. Date: Tue, 19 Feb 2008 09:13:59 +0530 Message-ID: <1203392640-14335-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Cc: linux-ext4@vger.kernel.org, "Aneesh Kumar K.V" To: tytso@mit.edu, cmm@us.ibm.com Return-path: Received: from E23SMTP06.au.ibm.com ([202.81.18.175]:41337 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751030AbYBSDoG (ORCPT ); Mon, 18 Feb 2008 22:44:06 -0500 Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [202.81.18.234]) by e23smtp06.au.ibm.com (8.13.1/8.13.1) with ESMTP id m1J3hrpc020283 for ; Tue, 19 Feb 2008 14:43:53 +1100 Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m1J3i2VO3948728 for ; Tue, 19 Feb 2008 14:44:04 +1100 Received: from d23av03.au.ibm.com (loopback [127.0.0.1]) by d23av03.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m1J3i5JB025106 for ; Tue, 19 Feb 2008 14:44:05 +1100 Sender: linux-ext4-owner@vger.kernel.org List-ID: We would like to get notified when we are doing a write on mmap section. This is needed with respect to preallocated area. We split the preallocated area into initialzed extent and uninitialzed extent in the call back. This let us handle ENOSPC better. Otherwise we get ENOSPC in the writepage and that would result in data loss. The changes are also needed to handle ENOSPC when writing to an mmap section of files with holes. Signed-off-by: Aneesh Kumar K.V --- fs/ext4/file.c | 19 ++++++++++++++++++- fs/ext4/inode.c | 6 ++++++ include/linux/ext4_fs.h | 1 + 3 files changed, 25 insertions(+), 1 deletions(-) diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 20507a2..77341c1 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -123,6 +123,23 @@ force_commit: return ret; } +static struct vm_operations_struct ext4_file_vm_ops = { + .fault = filemap_fault, + .page_mkwrite = ext4_page_mkwrite, +}; + +static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct address_space *mapping = file->f_mapping; + + if (!mapping->a_ops->readpage) + return -ENOEXEC; + file_accessed(file); + vma->vm_ops = &ext4_file_vm_ops; + vma->vm_flags |= VM_CAN_NONLINEAR; + return 0; +} + const struct file_operations ext4_file_operations = { .llseek = generic_file_llseek, .read = do_sync_read, @@ -133,7 +150,7 @@ const struct file_operations ext4_file_operations = { #ifdef CONFIG_COMPAT .compat_ioctl = ext4_compat_ioctl, #endif - .mmap = generic_file_mmap, + .mmap = ext4_file_mmap, .open = generic_file_open, .release = ext4_release_file, .fsync = ext4_sync_file, diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 34f3eb6..81faa67 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3466,3 +3466,9 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val) return err; } + +int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page) +{ + return block_page_mkwrite(vma, page, ext4_get_block); +} + diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h index 22810b1..8f5a563 100644 --- a/include/linux/ext4_fs.h +++ b/include/linux/ext4_fs.h @@ -1059,6 +1059,7 @@ extern void ext4_set_aops(struct inode *inode); extern int ext4_writepage_trans_blocks(struct inode *); extern int ext4_block_truncate_page(handle_t *handle, struct page *page, struct address_space *mapping, loff_t from); +extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page); /* ioctl.c */ extern long ext4_ioctl(struct file *, unsigned int, unsigned long); -- 1.5.4.1.97.g40aab-dirty