dax: remote unused fault wrappers
Remove the unused wrappers dax_fault() and dax_pmd_fault(). After this
removal, rename __dax_fault() and __dax_pmd_fault() to dax_fault() and
dax_pmd_fault() respectively, and update all callers.
The dax_fault() and dax_pmd_fault() wrappers were initially intended to
capture some filesystem independent functionality around page faults
(calling sb_start_pagefault() & sb_end_pagefault(), updating file mtime
and ctime).
However, the following commits:
5726b27b09cc ("ext2: Add locking for DAX faults")
ea3d7209ca01 ("ext4: fix races between page faults and hole punching")
added locking to the ext2 and ext4 filesystems after these common
operations but before __dax_fault() and __dax_pmd_fault() were called.
This means that these wrappers are no longer used, and are unlikely to
be used in the future.
XFS has had locking analogous to what was recently added to ext2 and
ext4 since DAX support was initially introduced by:
6b698edeeef0 ("xfs: add DAX file operations support")
Link: http://lkml.kernel.org/r/20160714214049.20075-2-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/dax.c b/fs/dax.c
index e207f8f..432b9e6 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -819,16 +819,16 @@
}
/**
- * __dax_fault - handle a page fault on a DAX file
+ * dax_fault - handle a page fault on a DAX file
* @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
*
* 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
+ * 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,
+int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
get_block_t get_block)
{
struct file *file = vma->vm_file;
@@ -913,33 +913,6 @@
return VM_FAULT_SIGBUS | major;
return VM_FAULT_NOPAGE | major;
}
-EXPORT_SYMBOL(__dax_fault);
-
-/**
- * dax_fault - handle a page fault on a DAX file
- * @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
- *
- * When a page fault occurs, filesystems may call this helper in their
- * fault handler for DAX files.
- */
-int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
- get_block_t get_block)
-{
- int result;
- struct super_block *sb = file_inode(vma->vm_file)->i_sb;
-
- if (vmf->flags & FAULT_FLAG_WRITE) {
- sb_start_pagefault(sb);
- file_update_time(vma->vm_file);
- }
- result = __dax_fault(vma, vmf, get_block);
- if (vmf->flags & FAULT_FLAG_WRITE)
- sb_end_pagefault(sb);
-
- return result;
-}
EXPORT_SYMBOL_GPL(dax_fault);
#if defined(CONFIG_TRANSPARENT_HUGEPAGE)
@@ -967,7 +940,16 @@
#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,
+/**
+ * dax_pmd_fault - handle a PMD fault on a DAX file
+ * @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
+ *
+ * When a page fault occurs, filesystems may call this helper in their
+ * 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)
{
struct file *file = vma->vm_file;
@@ -1119,7 +1101,7 @@
*
* The PMD path doesn't have an equivalent to
* dax_pfn_mkwrite(), though, so for a read followed by a
- * write we traverse all the way through __dax_pmd_fault()
+ * write we traverse all the way through dax_pmd_fault()
* twice. This means we can just skip inserting a radix tree
* entry completely on the initial read and just wait until
* the write to insert a dirty entry.
@@ -1148,33 +1130,6 @@
result = VM_FAULT_FALLBACK;
goto out;
}
-EXPORT_SYMBOL_GPL(__dax_pmd_fault);
-
-/**
- * dax_pmd_fault - handle a PMD fault on a DAX file
- * @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
- *
- * When a page fault occurs, filesystems may call this helper in their
- * 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)
-{
- int result;
- struct super_block *sb = file_inode(vma->vm_file)->i_sb;
-
- if (flags & FAULT_FLAG_WRITE) {
- sb_start_pagefault(sb);
- file_update_time(vma->vm_file);
- }
- result = __dax_pmd_fault(vma, address, pmd, flags, get_block);
- if (flags & FAULT_FLAG_WRITE)
- sb_end_pagefault(sb);
-
- return result;
-}
EXPORT_SYMBOL_GPL(dax_pmd_fault);
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */