Rashika Kheria <rashika.khe...@gmail.com> wrote:
> Remove unused function in afs/write.c.
>
> This eliminates the following warning in afs/write.c:
> fs/afs/write.c:749:5: warning: no previous prototype for ‘afs_page_mkwrite’
> [-Wmissing-prototypes]
>
> Signed-off-by: Rashika Kheria <rashika.khe...@gmail.com>
> Reviewed-by: Josh Triplett <j...@joshtriplett.org>
I would like to counter with the attached patch. Yes, I know that
afs_page_mkwrite() still won't be called after this patch - yet. I have
someone working on RxRPC and AFS stuff and I'd like to have him try and fix up
the missing stuff.
David
---
commit bf0e3d6fc98ba1567deea0a4182580d8041361aa
Author: David Howells <dhowe...@redhat.com>
Date: Thu Feb 13 13:40:57 2014 +0000
AFS: Actually use afs_page_mkwrite()
When afs_page_mkwrite() was added in commit:
9b3f26c9110dcea62716aca9b8c68ceb482227ef
FS-Cache: Make kAFS use FS-Cache
it wasn't actually called. It should be called, however, so that we don't
see
local changes not associated with the old data version appearing in
fscache's
cache (afs_page_mkwrite() holds up the write to a file's page through an
mmap'd page until that page has finished being written to the cache).
Signed-off-by: David Howells <dhowe...@redhat.com>
cc: Rashika Kheria <rashika.khe...@gmail.com>
cc: Josh Triplett <j...@joshtriplett.org>
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 66d50fe2ee45..014792a8d34e 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -18,6 +18,7 @@
#include <linux/gfp.h>
#include "internal.h"
+static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
static int afs_readpage(struct file *file, struct page *page);
static void afs_invalidatepage(struct page *page, unsigned int offset,
unsigned int length);
@@ -35,7 +36,7 @@ const struct file_operations afs_file_operations = {
.write = do_sync_write,
.aio_read = generic_file_aio_read,
.aio_write = afs_file_write,
- .mmap = generic_file_readonly_mmap,
+ .mmap = afs_file_mmap,
.splice_read = generic_file_splice_read,
.fsync = afs_fsync,
.lock = afs_lock,
@@ -378,3 +379,25 @@ static int afs_releasepage(struct page *page, gfp_t
gfp_flags)
_leave(" = T");
return 1;
}
+
+static const struct vm_operations_struct afs_vm_ops = {
+ .fault = filemap_fault,
+ .page_mkwrite = afs_page_mkwrite,
+ .remap_pages = generic_file_remap_pages,
+};
+
+/*
+ * Handle setting up a memory mapping on an AFS file.
+ *
+ * At the moment we only support read-only mappings as writable mappings must
+ * set up a writeback record.
+ */
+static int afs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ int ret;
+
+ ret = generic_file_readonly_mmap(file, vma);
+ if (ret == 0)
+ vma->vm_ops = &afs_vm_ops;
+ return ret;
+}
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 6621f8008122..a074279bdab7 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -750,6 +750,7 @@ extern ssize_t afs_file_write(struct kiocb *, const struct
iovec *,
unsigned long, loff_t);
extern int afs_writeback_all(struct afs_vnode *);
extern int afs_fsync(struct file *, loff_t, loff_t, int);
+extern int afs_page_mkwrite(struct vm_area_struct *, struct page *);
/*****************************************************************************/
diff --git a/fs/afs/write.c b/fs/afs/write.c
index a890db4b9898..a593c2c0970e 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -759,6 +759,13 @@ int afs_page_mkwrite(struct vm_area_struct *vma, struct
page *page)
fscache_wait_on_page_write(vnode->cache, page);
#endif
+ /* TODO: Get the key from vma->vm_file, flush any overlapping
+ * contradictory writeback record, set up new a writeback record if
+ * needed and remove the R/O check from afs_file_mmap().
+ *
+ * The code can probably be common with much of afs_write_begin().
+ */
+
_leave(" = 0");
return 0;
}
--
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