dax: use pfn_mkwrite to update c/mtime + freeze protection
From: Yigal Korman <yigal@plexistor.com> [v1] Without this patch, c/mtime is not updated correctly when mmap'ed page is first read from and then written to. A new xfstest is submitted for testing this (generic/080) [v2] Jan Kara has pointed out that if we add the sb_start/end_pagefault pair in the new pfn_mkwrite we are then fixing another bug where: A user could start writing to the page while filesystem is frozen. Signed-off-by: Yigal Korman <yigal@plexistor.com> Signed-off-by: Boaz Harrosh <boaz@plexistor.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
dd9061846a
commit
0e3b210ce1
17
fs/dax.c
17
fs/dax.c
|
@ -463,6 +463,23 @@ int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
|
||||||
}
|
}
|
||||||
EXPORT_SYMBOL_GPL(dax_fault);
|
EXPORT_SYMBOL_GPL(dax_fault);
|
||||||
|
|
||||||
|
/**
|
||||||
|
* dax_pfn_mkwrite - handle first write to DAX page
|
||||||
|
* @vma: The virtual memory area where the fault occurred
|
||||||
|
* @vmf: The description of the fault
|
||||||
|
*
|
||||||
|
*/
|
||||||
|
int dax_pfn_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
|
||||||
|
{
|
||||||
|
struct super_block *sb = file_inode(vma->vm_file)->i_sb;
|
||||||
|
|
||||||
|
sb_start_pagefault(sb);
|
||||||
|
file_update_time(vma->vm_file);
|
||||||
|
sb_end_pagefault(sb);
|
||||||
|
return VM_FAULT_NOPAGE;
|
||||||
|
}
|
||||||
|
EXPORT_SYMBOL_GPL(dax_pfn_mkwrite);
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* dax_zero_page_range - zero a range within a page of a DAX file
|
* dax_zero_page_range - zero a range within a page of a DAX file
|
||||||
* @inode: The file being truncated
|
* @inode: The file being truncated
|
||||||
|
|
|
@ -39,6 +39,7 @@ static int ext2_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
|
||||||
static const struct vm_operations_struct ext2_dax_vm_ops = {
|
static const struct vm_operations_struct ext2_dax_vm_ops = {
|
||||||
.fault = ext2_dax_fault,
|
.fault = ext2_dax_fault,
|
||||||
.page_mkwrite = ext2_dax_mkwrite,
|
.page_mkwrite = ext2_dax_mkwrite,
|
||||||
|
.pfn_mkwrite = dax_pfn_mkwrite,
|
||||||
};
|
};
|
||||||
|
|
||||||
static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma)
|
static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma)
|
||||||
|
|
|
@ -206,6 +206,7 @@ static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
|
||||||
static const struct vm_operations_struct ext4_dax_vm_ops = {
|
static const struct vm_operations_struct ext4_dax_vm_ops = {
|
||||||
.fault = ext4_dax_fault,
|
.fault = ext4_dax_fault,
|
||||||
.page_mkwrite = ext4_dax_mkwrite,
|
.page_mkwrite = ext4_dax_mkwrite,
|
||||||
|
.pfn_mkwrite = dax_pfn_mkwrite,
|
||||||
};
|
};
|
||||||
#else
|
#else
|
||||||
#define ext4_dax_vm_ops ext4_file_vm_ops
|
#define ext4_dax_vm_ops ext4_file_vm_ops
|
||||||
|
|
|
@ -2620,6 +2620,7 @@ int dax_clear_blocks(struct inode *, sector_t block, long size);
|
||||||
int dax_zero_page_range(struct inode *, loff_t from, unsigned len, get_block_t);
|
int dax_zero_page_range(struct inode *, loff_t from, unsigned len, get_block_t);
|
||||||
int dax_truncate_page(struct inode *, loff_t from, get_block_t);
|
int dax_truncate_page(struct inode *, loff_t from, get_block_t);
|
||||||
int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t);
|
int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t);
|
||||||
|
int dax_pfn_mkwrite(struct vm_area_struct *, struct vm_fault *);
|
||||||
#define dax_mkwrite(vma, vmf, gb) dax_fault(vma, vmf, gb)
|
#define dax_mkwrite(vma, vmf, gb) dax_fault(vma, vmf, gb)
|
||||||
|
|
||||||
#ifdef CONFIG_BLOCK
|
#ifdef CONFIG_BLOCK
|
||||||
|
|
Loading…
Reference in New Issue