[RFC 11/11] ext4: add ext4_dax_pfn_mkwrite()
From: Ross Zwisler <hidden>
Date: 2015-10-29 20:12:15
Also in:
linux-fsdevel, linux-mm, linux-xfs, lkml, nvdimm
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
Add ext4_dax_pfn_mkwrite() that properly protects against freeze, sets the file update time and calls into dax_pfn_mkwrite() to add the newly dirtied page to the radix tree which tracks dirty DAX pages. Signed-off-by: Ross Zwisler <redacted> --- fs/ext4/file.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 54d7729..7f62cad 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c@@ -272,11 +272,31 @@ static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) ext4_end_io_unwritten); } +static int ext4_dax_pfn_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct inode *inode = file_inode(vma->vm_file); + loff_t size; + int ret; + + sb_start_pagefault(inode->i_sb); + file_update_time(vma->vm_file); + + /* check that the faulting page hasn't raced with truncate */ + 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); + + sb_end_pagefault(inode->i_sb); + return ret; +} + static const struct vm_operations_struct ext4_dax_vm_ops = { .fault = ext4_dax_fault, .pmd_fault = ext4_dax_pmd_fault, .page_mkwrite = ext4_dax_mkwrite, - .pfn_mkwrite = dax_pfn_mkwrite, + .pfn_mkwrite = ext4_dax_pfn_mkwrite, }; #else #define ext4_dax_vm_ops ext4_file_vm_ops
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2.1.0
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