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 <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/fs/dax.c b/fs/dax.c
index 5214ed9..5ddf151 100644 (file)
--- 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 @@ fallback:
        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 @@ out:
        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 ff3a363..d2bb7c9 100644 (file)
--- 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 b1da660..3cec0b9 100644 (file)
--- 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 309e26c..7c6b8de 100644 (file)
--- 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 1221971..e7fa4b8 100644 (file)
--- 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);