[PATCH v2 10/11] ext4: add support for DAX fsync/msync
From: Ross Zwisler <hidden>
Date: 2015-11-14 00:06:49
Also in:
linux-ext4, linux-fsdevel, linux-xfs, lkml, nvdimm
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
To properly support the new DAX fsync/msync infrastructure filesystems need to call dax_pfn_mkwrite() so that DAX can properly track when a user write faults on a previously cleaned address. They also need to call dax_fsync() in the filesystem fsync() path. This dax_fsync() call uses addresses retrieved from get_block() so it needs to be ordered with respect to truncate. This is accomplished by using the same locking that was set up for DAX page faults. Signed-off-by: Ross Zwisler <redacted> --- fs/ext4/file.c | 4 +++- fs/ext4/fsync.c | 12 ++++++++++-- 2 files changed, 13 insertions(+), 3 deletions(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 749b222..8c8965c 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c@@ -291,8 +291,8 @@ static int ext4_dax_pfn_mkwrite(struct vm_area_struct *vma, { struct inode *inode = file_inode(vma->vm_file); struct super_block *sb = inode->i_sb; - int ret = VM_FAULT_NOPAGE; loff_t size; + int ret; sb_start_pagefault(sb); file_update_time(vma->vm_file);
@@ -300,6 +300,8 @@ static int ext4_dax_pfn_mkwrite(struct vm_area_struct *vma, size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; if (vmf->pgoff >= size) ret = VM_FAULT_SIGBUS; + else + ret = dax_pfn_mkwrite(vma, vmf); up_read(&EXT4_I(inode)->i_mmap_sem); sb_end_pagefault(sb);
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 8850254..e87c29b 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c@@ -27,6 +27,7 @@ #include <linux/sched.h> #include <linux/writeback.h> #include <linux/blkdev.h> +#include <linux/dax.h> #include "ext4.h" #include "ext4_jbd2.h"
@@ -86,7 +87,8 @@ static int ext4_sync_parent(struct inode *inode) int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync) { - struct inode *inode = file->f_mapping->host; + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; struct ext4_inode_info *ei = EXT4_I(inode); journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; int ret = 0, err;
@@ -112,7 +114,13 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync) goto out; } - ret = filemap_write_and_wait_range(inode->i_mapping, start, end); + if (dax_mapping(mapping)) { + down_read(&ei->i_mmap_sem); + dax_fsync(mapping, start, end); + up_read(&ei->i_mmap_sem); + } + + ret = filemap_write_and_wait_range(mapping, start, end); if (ret) return ret; /*
--
2.1.0
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