The patch titled Subject: dax: use pfn_mkwrite to update c/mtime + freeze protection has been added to the -mm tree. Its filename is dax-use-pfn_mkwrite-to-update-c-mtime-freeze-protection.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/dax-use-pfn_mkwrite-to-update-c-mtime-freeze-protection.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/dax-use-pfn_mkwrite-to-update-c-mtime-freeze-protection.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Boaz Harrosh <boaz@xxxxxxxxxxxxx> Subject: dax: use pfn_mkwrite to update c/mtime + freeze protection [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@xxxxxxxxxxxxx> Signed-off-by: Boaz Harrosh <boaz@xxxxxxxxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> Cc: Matthew Wilcox <matthew.r.wilcox@xxxxxxxxx> Cc: Dave Chinner <david@xxxxxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/dax.c | 17 +++++++++++++++++ fs/ext2/file.c | 1 + fs/ext4/file.c | 1 + include/linux/fs.h | 1 + 4 files changed, 20 insertions(+) diff -puN fs/dax.c~dax-use-pfn_mkwrite-to-update-c-mtime-freeze-protection fs/dax.c --- a/fs/dax.c~dax-use-pfn_mkwrite-to-update-c-mtime-freeze-protection +++ a/fs/dax.c @@ -464,6 +464,23 @@ int dax_fault(struct vm_area_struct *vma 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 * @inode: The file being truncated * @from: The file offset that is being truncated to diff -puN fs/ext2/file.c~dax-use-pfn_mkwrite-to-update-c-mtime-freeze-protection fs/ext2/file.c --- a/fs/ext2/file.c~dax-use-pfn_mkwrite-to-update-c-mtime-freeze-protection +++ a/fs/ext2/file.c @@ -39,6 +39,7 @@ static int ext2_dax_mkwrite(struct vm_ar static const struct vm_operations_struct ext2_dax_vm_ops = { .fault = ext2_dax_fault, .page_mkwrite = ext2_dax_mkwrite, + .pfn_mkwrite = dax_pfn_mkwrite, }; static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma) diff -puN fs/ext4/file.c~dax-use-pfn_mkwrite-to-update-c-mtime-freeze-protection fs/ext4/file.c --- a/fs/ext4/file.c~dax-use-pfn_mkwrite-to-update-c-mtime-freeze-protection +++ a/fs/ext4/file.c @@ -206,6 +206,7 @@ static int ext4_dax_mkwrite(struct vm_ar static const struct vm_operations_struct ext4_dax_vm_ops = { .fault = ext4_dax_fault, .page_mkwrite = ext4_dax_mkwrite, + .pfn_mkwrite = dax_pfn_mkwrite, }; #else #define ext4_dax_vm_ops ext4_file_vm_ops diff -puN include/linux/fs.h~dax-use-pfn_mkwrite-to-update-c-mtime-freeze-protection include/linux/fs.h --- a/include/linux/fs.h~dax-use-pfn_mkwrite-to-update-c-mtime-freeze-protection +++ a/include/linux/fs.h @@ -2598,6 +2598,7 @@ int dax_clear_blocks(struct inode *, sec 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_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) #ifdef CONFIG_BLOCK _ Patches currently in -mm which might be from boaz@xxxxxxxxxxxxx are mmv41-new-pfn_mkwrite-same-as-page_mkwrite-for-vm_pfnmap.patch dax-use-pfn_mkwrite-to-update-c-mtime-freeze-protection.patch dax-unify-ext2-4_dax_file_operations.patch gitignore-ignore-tar.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html