2017-11-01 15:36:39

by Jan Kara

[permalink] [raw]
Subject: [PATCH 10/18] dax: Allow dax_iomap_fault() to return pfn

For synchronous page fault dax_iomap_fault() will need to return PFN
which will then need to be inserted into page tables after fsync()
completes. Add necessary parameter to dax_iomap_fault().

Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/[email protected]>
Signed-off-by: Jan Kara <[email protected]>
---
fs/dax.c | 13 +++++++------
fs/ext2/file.c | 2 +-
fs/ext4/file.c | 2 +-
fs/xfs/xfs_file.c | 4 ++--
include/linux/dax.h | 2 +-
5 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 5214ed9ba508..5ddf15161390 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1079,7 +1079,7 @@ static int dax_fault_return(int error)
return VM_FAULT_SIGBUS;
}

-static int dax_iomap_pte_fault(struct vm_fault *vmf,
+static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
struct vm_area_struct *vma = vmf->vma;
@@ -1280,7 +1280,7 @@ static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
return VM_FAULT_FALLBACK;
}

-static int dax_iomap_pmd_fault(struct vm_fault *vmf,
+static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
struct vm_area_struct *vma = vmf->vma;
@@ -1425,7 +1425,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
return result;
}
#else
-static int dax_iomap_pmd_fault(struct vm_fault *vmf,
+static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
return VM_FAULT_FALLBACK;
@@ -1436,6 +1436,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
* dax_iomap_fault - handle a page fault on a DAX file
* @vmf: The description of the fault
* @pe_size: Size of the page to fault in
+ * @pfnp: PFN to insert for synchronous faults if fsync is required
* @ops: Iomap ops passed from the file system
*
* When a page fault occurs, filesystems may call this helper in
@@ -1444,13 +1445,13 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
* successfully.
*/
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
- const struct iomap_ops *ops)
+ pfn_t *pfnp, const struct iomap_ops *ops)
{
switch (pe_size) {
case PE_SIZE_PTE:
- return dax_iomap_pte_fault(vmf, ops);
+ return dax_iomap_pte_fault(vmf, pfnp, ops);
case PE_SIZE_PMD:
- return dax_iomap_pmd_fault(vmf, ops);
+ return dax_iomap_pmd_fault(vmf, pfnp, ops);
default:
return VM_FAULT_FALLBACK;
}
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index ff3a3636a5ca..d2bb7c96307d 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -99,7 +99,7 @@ static int ext2_dax_fault(struct vm_fault *vmf)
}
down_read(&ei->dax_sem);

- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &ext2_iomap_ops);
+ ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &ext2_iomap_ops);

up_read(&ei->dax_sem);
if (vmf->flags & FAULT_FLAG_WRITE)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index b1da660ac3bc..3cec0b95672f 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -306,7 +306,7 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
down_read(&EXT4_I(inode)->i_mmap_sem);
}
if (!IS_ERR(handle))
- result = dax_iomap_fault(vmf, pe_size, &ext4_iomap_ops);
+ result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
else
result = VM_FAULT_SIGBUS;
if (write) {
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 309e26c9dddb..7c6b8def6eed 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1040,7 +1040,7 @@ __xfs_filemap_fault(

xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = dax_iomap_fault(vmf, pe_size, &xfs_iomap_ops);
+ ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops);
} else {
if (write_fault)
ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
@@ -1111,7 +1111,7 @@ xfs_filemap_pfn_mkwrite(
if (vmf->pgoff >= size)
ret = VM_FAULT_SIGBUS;
else if (IS_DAX(inode))
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &xfs_iomap_ops);
+ ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
sb_end_pagefault(inode->i_sb);
return ret;
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 122197124b9d..e7fa4b8f45bc 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -95,7 +95,7 @@ bool dax_write_cache_enabled(struct dax_device *dax_dev);
ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops);
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
- const struct iomap_ops *ops);
+ pfn_t *pfnp, const struct iomap_ops *ops);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index);
--
2.12.3