[PATCH 17/37] CacheFiles: Add a hook to write a single page of data to an inode
Add an address space operation to write one single page of data to an inode at
a page-aligned location (thus permitting the implementation to be highly
optimised). The data source is a single page.
This is used by CacheFiles to store the contents of netfs pages into their
backing file pages.
Supply a generic implementation for this that uses the write_begin() and
write_end() address_space operations to bind a copy directly into the page
cache.
Hook the Ext2 and Ext3 operations to the generic implementation.
Signed-off-by: David Howells <[EMAIL PROTECTED]>
---
fs/ext2/inode.c|2 ++
fs/ext3/inode.c|3 +++
include/linux/fs.h |7 ++
mm/filemap.c | 61
4 files changed, 73 insertions(+), 0 deletions(-)
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index c620068..f483014 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -792,6 +792,7 @@ const struct address_space_operations ext2_aops = {
.direct_IO = ext2_direct_IO,
.writepages = ext2_writepages,
.migratepage= buffer_migrate_page,
+ .write_one_page = generic_file_buffered_write_one_page,
};
const struct address_space_operations ext2_aops_xip = {
@@ -810,6 +811,7 @@ const struct address_space_operations ext2_nobh_aops = {
.direct_IO = ext2_direct_IO,
.writepages = ext2_writepages,
.migratepage= buffer_migrate_page,
+ .write_one_page = generic_file_buffered_write_one_page,
};
/*
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index c976123..0209f3b 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1776,6 +1776,7 @@ static const struct address_space_operations
ext3_ordered_aops = {
.releasepage= ext3_releasepage,
.direct_IO = ext3_direct_IO,
.migratepage= buffer_migrate_page,
+ .write_one_page = generic_file_buffered_write_one_page,
};
static const struct address_space_operations ext3_writeback_aops = {
@@ -1790,6 +1791,7 @@ static const struct address_space_operations
ext3_writeback_aops = {
.releasepage= ext3_releasepage,
.direct_IO = ext3_direct_IO,
.migratepage= buffer_migrate_page,
+ .write_one_page = generic_file_buffered_write_one_page,
};
static const struct address_space_operations ext3_journalled_aops = {
@@ -1803,6 +1805,7 @@ static const struct address_space_operations
ext3_journalled_aops = {
.bmap = ext3_bmap,
.invalidatepage = ext3_invalidatepage,
.releasepage= ext3_releasepage,
+ .write_one_page = generic_file_buffered_write_one_page,
};
void ext3_set_aops(struct inode *inode)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d218ef5..dd6c3d1 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -481,6 +481,11 @@ struct address_space_operations {
int (*migratepage) (struct address_space *,
struct page *, struct page *);
int (*launder_page) (struct page *);
+ /* write the contents of the source page over the page at the specified
+* index in the target address space (the source page does not need to
+* be related to the target address space) */
+ int (*write_one_page)(struct address_space *, pgoff_t, struct page *);
+
};
/*
@@ -1811,6 +1816,8 @@ extern ssize_t generic_file_direct_write(struct kiocb *,
const struct iovec *,
unsigned long *, loff_t, loff_t *, size_t, size_t);
extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec
*,
unsigned long, loff_t, loff_t *, size_t, ssize_t);
+extern int generic_file_buffered_write_one_page(struct address_space *,
+ pgoff_t, struct page *);
extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len,
loff_t *ppos);
extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t
len, loff_t *ppos);
extern int generic_segment_checks(const struct iovec *iov,
diff --git a/mm/filemap.c b/mm/filemap.c
index df1e149..a583f44 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2359,6 +2359,67 @@ generic_file_buffered_write(struct kiocb *iocb, const
struct iovec *iov,
}
EXPORT_SYMBOL(generic_file_buffered_write);
+/**
+ * generic_file_buffered_write_one_page - Write a single page of data to an
+ * inode
+ * @mapping - The address space of the target inode
+ * @index - The target page in the target inode to fill
+ * @source - The data to write into the target page
+ *
+ * Write the data from the source page to the page in the nominated address
+ * space at the @index specified. Note that the file will not be extended if
+ * the page crosses the EOF marker, in which case only the first part of the
+ * page will be written.
+ *
+ * The @source page does not need to have any association with the fi
[PATCH 17/37] CacheFiles: Add a hook to write a single page of data to an inode
Add an address space operation to write one single page of data to an inode at
a page-aligned location (thus permitting the implementation to be highly
optimised). The data source is a single page.
This is used by CacheFiles to store the contents of netfs pages into their
backing file pages.
Supply a generic implementation for this that uses the write_begin() and
write_end() address_space operations to bind a copy directly into the page
cache.
Hook the Ext2 and Ext3 operations to the generic implementation.
Signed-off-by: David Howells <[EMAIL PROTECTED]>
---
fs/ext2/inode.c|2 ++
fs/ext3/inode.c|3 +++
include/linux/fs.h |7 ++
mm/filemap.c | 61
4 files changed, 73 insertions(+), 0 deletions(-)
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index c620068..f483014 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -792,6 +792,7 @@ const struct address_space_operations ext2_aops = {
.direct_IO = ext2_direct_IO,
.writepages = ext2_writepages,
.migratepage= buffer_migrate_page,
+ .write_one_page = generic_file_buffered_write_one_page,
};
const struct address_space_operations ext2_aops_xip = {
@@ -810,6 +811,7 @@ const struct address_space_operations ext2_nobh_aops = {
.direct_IO = ext2_direct_IO,
.writepages = ext2_writepages,
.migratepage= buffer_migrate_page,
+ .write_one_page = generic_file_buffered_write_one_page,
};
/*
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index c976123..0209f3b 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1776,6 +1776,7 @@ static const struct address_space_operations
ext3_ordered_aops = {
.releasepage= ext3_releasepage,
.direct_IO = ext3_direct_IO,
.migratepage= buffer_migrate_page,
+ .write_one_page = generic_file_buffered_write_one_page,
};
static const struct address_space_operations ext3_writeback_aops = {
@@ -1790,6 +1791,7 @@ static const struct address_space_operations
ext3_writeback_aops = {
.releasepage= ext3_releasepage,
.direct_IO = ext3_direct_IO,
.migratepage= buffer_migrate_page,
+ .write_one_page = generic_file_buffered_write_one_page,
};
static const struct address_space_operations ext3_journalled_aops = {
@@ -1803,6 +1805,7 @@ static const struct address_space_operations
ext3_journalled_aops = {
.bmap = ext3_bmap,
.invalidatepage = ext3_invalidatepage,
.releasepage= ext3_releasepage,
+ .write_one_page = generic_file_buffered_write_one_page,
};
void ext3_set_aops(struct inode *inode)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index feea65d..35525c4 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -481,6 +481,11 @@ struct address_space_operations {
int (*migratepage) (struct address_space *,
struct page *, struct page *);
int (*launder_page) (struct page *);
+ /* write the contents of the source page over the page at the specified
+* index in the target address space (the source page does not need to
+* be related to the target address space) */
+ int (*write_one_page)(struct address_space *, pgoff_t, struct page *);
+
};
/*
@@ -1805,6 +1810,8 @@ extern ssize_t generic_file_direct_write(struct kiocb *,
const struct iovec *,
unsigned long *, loff_t, loff_t *, size_t, size_t);
extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec
*,
unsigned long, loff_t, loff_t *, size_t, ssize_t);
+extern int generic_file_buffered_write_one_page(struct address_space *,
+ pgoff_t, struct page *);
extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len,
loff_t *ppos);
extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t
len, loff_t *ppos);
extern void do_generic_mapping_read(struct address_space *mapping,
diff --git a/mm/filemap.c b/mm/filemap.c
index 89f5a5e..6c6cd76 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2367,6 +2367,67 @@ generic_file_buffered_write(struct kiocb *iocb, const
struct iovec *iov,
}
EXPORT_SYMBOL(generic_file_buffered_write);
+/**
+ * generic_file_buffered_write_one_page - Write a single page of data to an
+ * inode
+ * @mapping - The address space of the target inode
+ * @index - The target page in the target inode to fill
+ * @source - The data to write into the target page
+ *
+ * Write the data from the source page to the page in the nominated address
+ * space at the @index specified. Note that the file will not be extended if
+ * the page crosses the EOF marker, in which case only the first part of the
+ * page will be written.
+ *
+ * The @source page does not need to have any association wit
