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Date: Mon, 18 Apr 2016 23:35:27 +0200
From: Jan Kara <jack@...e.cz>
To: linux-fsdevel@...r.kernel.org
Cc: linux-ext4@...r.kernel.org, linux-mm@...ck.org,
Ross Zwisler <ross.zwisler@...ux.intel.com>,
Dan Williams <dan.j.williams@...el.com>,
linux-nvdimm@...ts.01.org, Matthew Wilcox <willy@...ux.intel.com>,
Jan Kara <jack@...e.cz>
Subject: [PATCH 04/18] dax: Remove complete_unwritten argument
Fault handlers currently take complete_unwritten argument to convert
unwritten extents after PTEs are updated. However no filesystem uses
this anymore as the code is racy. Remove the unused argument.
Reviewed-by: Ross Zwisler <ross.zwisler@...ux.intel.com>
Signed-off-by: Jan Kara <jack@...e.cz>
---
fs/block_dev.c | 4 ++--
fs/dax.c | 43 +++++++++----------------------------------
fs/ext2/file.c | 4 ++--
fs/ext4/file.c | 4 ++--
fs/xfs/xfs_file.c | 7 +++----
include/linux/dax.h | 17 +++++++----------
include/linux/fs.h | 1 -
7 files changed, 25 insertions(+), 55 deletions(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 20a2c02b77c4..b25bb230b28a 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1746,7 +1746,7 @@ static const struct address_space_operations def_blk_aops = {
*/
static int blkdev_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
- return __dax_fault(vma, vmf, blkdev_get_block, NULL);
+ return __dax_fault(vma, vmf, blkdev_get_block);
}
static int blkdev_dax_pfn_mkwrite(struct vm_area_struct *vma,
@@ -1758,7 +1758,7 @@ static int blkdev_dax_pfn_mkwrite(struct vm_area_struct *vma,
static int blkdev_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd, unsigned int flags)
{
- return __dax_pmd_fault(vma, addr, pmd, flags, blkdev_get_block, NULL);
+ return __dax_pmd_fault(vma, addr, pmd, flags, blkdev_get_block);
}
static const struct vm_operations_struct blkdev_dax_vm_ops = {
diff --git a/fs/dax.c b/fs/dax.c
index 08799a510b4d..c5ccf745d279 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -612,19 +612,13 @@ static int dax_insert_mapping(struct inode *inode, struct buffer_head *bh,
* @vma: The virtual memory area where the fault occurred
* @vmf: The description of the fault
* @get_block: The filesystem method used to translate file offsets to blocks
- * @complete_unwritten: The filesystem method used to convert unwritten blocks
- * to written so the data written to them is exposed. This is required for
- * required by write faults for filesystems that will return unwritten
- * extent mappings from @get_block, but it is optional for reads as
- * dax_insert_mapping() will always zero unwritten blocks. If the fs does
- * not support unwritten extents, the it should pass NULL.
*
* When a page fault occurs, filesystems may call this helper in their
* fault handler for DAX files. __dax_fault() assumes the caller has done all
* the necessary locking for the page fault to proceed successfully.
*/
int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
- get_block_t get_block, dax_iodone_t complete_unwritten)
+ get_block_t get_block)
{
struct file *file = vma->vm_file;
struct address_space *mapping = file->f_mapping;
@@ -727,23 +721,9 @@ int __dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
page = NULL;
}
- /*
- * If we successfully insert the new mapping over an unwritten extent,
- * we need to ensure we convert the unwritten extent. If there is an
- * error inserting the mapping, the filesystem needs to leave it as
- * unwritten to prevent exposure of the stale underlying data to
- * userspace, but we still need to call the completion function so
- * the private resources on the mapping buffer can be released. We
- * indicate what the callback should do via the uptodate variable, same
- * as for normal BH based IO completions.
- */
+ /* Filesystem should not return unwritten buffers to us! */
+ WARN_ON_ONCE(buffer_unwritten(&bh));
error = dax_insert_mapping(inode, &bh, vma, vmf);
- if (buffer_unwritten(&bh)) {
- if (complete_unwritten)
- complete_unwritten(&bh, !error);
- else
- WARN_ON_ONCE(!(vmf->flags & FAULT_FLAG_WRITE));
- }
out:
if (error == -ENOMEM)
@@ -772,7 +752,7 @@ EXPORT_SYMBOL(__dax_fault);
* fault handler for DAX files.
*/
int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
- get_block_t get_block, dax_iodone_t complete_unwritten)
+ get_block_t get_block)
{
int result;
struct super_block *sb = file_inode(vma->vm_file)->i_sb;
@@ -781,7 +761,7 @@ int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
sb_start_pagefault(sb);
file_update_time(vma->vm_file);
}
- result = __dax_fault(vma, vmf, get_block, complete_unwritten);
+ result = __dax_fault(vma, vmf, get_block);
if (vmf->flags & FAULT_FLAG_WRITE)
sb_end_pagefault(sb);
@@ -815,8 +795,7 @@ static void __dax_dbg(struct buffer_head *bh, unsigned long address,
#define dax_pmd_dbg(bh, address, reason) __dax_dbg(bh, address, reason, "dax_pmd")
int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
- pmd_t *pmd, unsigned int flags, get_block_t get_block,
- dax_iodone_t complete_unwritten)
+ pmd_t *pmd, unsigned int flags, get_block_t get_block)
{
struct file *file = vma->vm_file;
struct address_space *mapping = file->f_mapping;
@@ -875,6 +854,7 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
if (get_block(inode, block, &bh, 1) != 0)
return VM_FAULT_SIGBUS;
alloc = true;
+ WARN_ON_ONCE(buffer_unwritten(&bh));
}
bdev = bh.b_bdev;
@@ -1020,9 +1000,6 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
out:
i_mmap_unlock_read(mapping);
- if (buffer_unwritten(&bh))
- complete_unwritten(&bh, !(result & VM_FAULT_ERROR));
-
return result;
fallback:
@@ -1042,8 +1019,7 @@ EXPORT_SYMBOL_GPL(__dax_pmd_fault);
* pmd_fault handler for DAX files.
*/
int dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
- pmd_t *pmd, unsigned int flags, get_block_t get_block,
- dax_iodone_t complete_unwritten)
+ pmd_t *pmd, unsigned int flags, get_block_t get_block)
{
int result;
struct super_block *sb = file_inode(vma->vm_file)->i_sb;
@@ -1052,8 +1028,7 @@ int dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
sb_start_pagefault(sb);
file_update_time(vma->vm_file);
}
- result = __dax_pmd_fault(vma, address, pmd, flags, get_block,
- complete_unwritten);
+ result = __dax_pmd_fault(vma, address, pmd, flags, get_block);
if (flags & FAULT_FLAG_WRITE)
sb_end_pagefault(sb);
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index c1400b109805..868c02317b05 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -51,7 +51,7 @@ static int ext2_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
}
down_read(&ei->dax_sem);
- ret = __dax_fault(vma, vmf, ext2_get_block, NULL);
+ ret = __dax_fault(vma, vmf, ext2_get_block);
up_read(&ei->dax_sem);
if (vmf->flags & FAULT_FLAG_WRITE)
@@ -72,7 +72,7 @@ static int ext2_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
}
down_read(&ei->dax_sem);
- ret = __dax_pmd_fault(vma, addr, pmd, flags, ext2_get_block, NULL);
+ ret = __dax_pmd_fault(vma, addr, pmd, flags, ext2_get_block);
up_read(&ei->dax_sem);
if (flags & FAULT_FLAG_WRITE)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index fa2208bae2e1..b3a9c6eeadbc 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -207,7 +207,7 @@ static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
if (IS_ERR(handle))
result = VM_FAULT_SIGBUS;
else
- result = __dax_fault(vma, vmf, ext4_dax_mmap_get_block, NULL);
+ result = __dax_fault(vma, vmf, ext4_dax_mmap_get_block);
if (write) {
if (!IS_ERR(handle))
@@ -243,7 +243,7 @@ static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
result = VM_FAULT_SIGBUS;
else
result = __dax_pmd_fault(vma, addr, pmd, flags,
- ext4_dax_mmap_get_block, NULL);
+ ext4_dax_mmap_get_block);
if (write) {
if (!IS_ERR(handle))
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 569938a4a357..c2946f436a3a 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1558,7 +1558,7 @@ xfs_filemap_page_mkwrite(
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = __dax_mkwrite(vma, vmf, xfs_get_blocks_dax_fault, NULL);
+ ret = __dax_mkwrite(vma, vmf, xfs_get_blocks_dax_fault);
} else {
ret = block_page_mkwrite(vma, vmf, xfs_get_blocks);
ret = block_page_mkwrite_return(ret);
@@ -1592,7 +1592,7 @@ xfs_filemap_fault(
* changes to xfs_get_blocks_direct() to map unwritten extent
* ioend for conversion on read-only mappings.
*/
- ret = __dax_fault(vma, vmf, xfs_get_blocks_dax_fault, NULL);
+ ret = __dax_fault(vma, vmf, xfs_get_blocks_dax_fault);
} else
ret = filemap_fault(vma, vmf);
xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
@@ -1629,8 +1629,7 @@ xfs_filemap_pmd_fault(
}
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
- ret = __dax_pmd_fault(vma, addr, pmd, flags, xfs_get_blocks_dax_fault,
- NULL);
+ ret = __dax_pmd_fault(vma, addr, pmd, flags, xfs_get_blocks_dax_fault);
xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (flags & FAULT_FLAG_WRITE)
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 636dd59ab505..7c45ac7ea1d1 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -10,10 +10,8 @@ ssize_t dax_do_io(struct kiocb *, struct inode *, struct iov_iter *, loff_t,
int dax_clear_sectors(struct block_device *bdev, sector_t _sector, long _size);
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,
- dax_iodone_t);
-int __dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t,
- dax_iodone_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);
#ifdef CONFIG_FS_DAX
struct page *read_dax_sector(struct block_device *bdev, sector_t n);
@@ -27,21 +25,20 @@ static inline struct page *read_dax_sector(struct block_device *bdev,
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
int dax_pmd_fault(struct vm_area_struct *, unsigned long addr, pmd_t *,
- unsigned int flags, get_block_t, dax_iodone_t);
+ unsigned int flags, get_block_t);
int __dax_pmd_fault(struct vm_area_struct *, unsigned long addr, pmd_t *,
- unsigned int flags, get_block_t, dax_iodone_t);
+ unsigned int flags, get_block_t);
#else
static inline int dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
- pmd_t *pmd, unsigned int flags, get_block_t gb,
- dax_iodone_t di)
+ pmd_t *pmd, unsigned int flags, get_block_t gb)
{
return VM_FAULT_FALLBACK;
}
#define __dax_pmd_fault dax_pmd_fault
#endif
int dax_pfn_mkwrite(struct vm_area_struct *, struct vm_fault *);
-#define dax_mkwrite(vma, vmf, gb, iod) dax_fault(vma, vmf, gb, iod)
-#define __dax_mkwrite(vma, vmf, gb, iod) __dax_fault(vma, vmf, gb, iod)
+#define dax_mkwrite(vma, vmf, gb) dax_fault(vma, vmf, gb)
+#define __dax_mkwrite(vma, vmf, gb) __dax_fault(vma, vmf, gb)
static inline bool vma_is_dax(struct vm_area_struct *vma)
{
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 70e61b58baaf..9f2813090d1b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -74,7 +74,6 @@ typedef int (get_block_t)(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create);
typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
ssize_t bytes, void *private);
-typedef void (dax_iodone_t)(struct buffer_head *bh_map, int uptodate);
#define MAY_EXEC 0x00000001
#define MAY_WRITE 0x00000002
--
2.6.6
--
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