ocfs2: rework ocfs2_buffered_write_cluster()

Use some ideas from the new-aops patch series and turn
ocfs2_buffered_write_cluster() into a 2 stage operation with the caller
copying data in between. The code now understands multiple cluster writes as
a result of having to deal with a full page write for greater than 4k pages.

This sets us up to easily call into the write path during ->page_mkwrite().

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This commit is contained in:
Mark Fasheh 2007-05-08 17:47:32 -07:00
parent 2e89b2e48e
commit 3a307ffc27
3 changed files with 569 additions and 456 deletions

File diff suppressed because it is too large Load diff

View file

@ -42,57 +42,13 @@ int walk_page_buffers( handle_t *handle,
int (*fn)( handle_t *handle,
struct buffer_head *bh));
struct ocfs2_write_ctxt;
typedef int (ocfs2_page_writer)(struct inode *, struct ocfs2_write_ctxt *,
u64 *, unsigned int *, unsigned int *);
int ocfs2_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata);
ssize_t ocfs2_buffered_write_cluster(struct file *file, loff_t pos,
size_t count, ocfs2_page_writer *actor,
void *priv);
struct ocfs2_write_ctxt {
size_t w_count;
loff_t w_pos;
u32 w_cpos;
unsigned int w_finished_copy;
/* This is true if page_size > cluster_size */
unsigned int w_large_pages;
/* Filler callback and private data */
ocfs2_page_writer *w_write_data_page;
void *w_private;
/* Only valid for the filler callback */
struct page *w_this_page;
unsigned int w_this_page_new;
};
struct ocfs2_buffered_write_priv {
char *b_src_buf;
const struct iovec *b_cur_iov; /* Current iovec */
size_t b_cur_off; /* Offset in the
* current iovec */
};
int ocfs2_map_and_write_user_data(struct inode *inode,
struct ocfs2_write_ctxt *wc,
u64 *p_blkno,
unsigned int *ret_from,
unsigned int *ret_to);
struct ocfs2_splice_write_priv {
struct splice_desc *s_sd;
struct pipe_buffer *s_buf;
struct pipe_inode_info *s_pipe;
/* Neither offset value is ever larger than one page */
unsigned int s_offset;
unsigned int s_buf_offset;
};
int ocfs2_map_and_write_splice_data(struct inode *inode,
struct ocfs2_write_ctxt *wc,
u64 *p_blkno,
unsigned int *ret_from,
unsigned int *ret_to);
int ocfs2_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
/* all ocfs2_dio_end_io()'s fault */
#define ocfs2_iocb_is_rw_locked(iocb) \

View file

@ -1335,15 +1335,16 @@ ocfs2_set_next_iovec(const struct iovec **iovp, size_t *basep, size_t bytes)
*basep = base;
}
static struct page * ocfs2_get_write_source(struct ocfs2_buffered_write_priv *bp,
static struct page * ocfs2_get_write_source(char **ret_src_buf,
const struct iovec *cur_iov,
size_t iov_offset)
{
int ret;
char *buf;
char *buf = cur_iov->iov_base + iov_offset;
struct page *src_page = NULL;
unsigned long off;
buf = cur_iov->iov_base + iov_offset;
off = (unsigned long)(buf) & ~PAGE_CACHE_MASK;
if (!segment_eq(get_fs(), KERNEL_DS)) {
/*
@ -1355,18 +1356,17 @@ static struct page * ocfs2_get_write_source(struct ocfs2_buffered_write_priv *bp
(unsigned long)buf & PAGE_CACHE_MASK, 1,
0, 0, &src_page, NULL);
if (ret == 1)
bp->b_src_buf = kmap(src_page);
*ret_src_buf = kmap(src_page) + off;
else
src_page = ERR_PTR(-EFAULT);
} else {
bp->b_src_buf = buf;
*ret_src_buf = buf;
}
return src_page;
}
static void ocfs2_put_write_source(struct ocfs2_buffered_write_priv *bp,
struct page *page)
static void ocfs2_put_write_source(struct page *page)
{
if (page) {
kunmap(page);
@ -1382,10 +1382,12 @@ static ssize_t ocfs2_file_buffered_write(struct file *file, loff_t *ppos,
{
int ret = 0;
ssize_t copied, total = 0;
size_t iov_offset = 0;
size_t iov_offset = 0, bytes;
loff_t pos;
const struct iovec *cur_iov = iov;
struct ocfs2_buffered_write_priv bp;
struct page *page;
struct page *user_page, *page;
char *buf, *dst;
void *fsdata;
/*
* handle partial DIO write. Adjust cur_iov if needed.
@ -1393,21 +1395,38 @@ static ssize_t ocfs2_file_buffered_write(struct file *file, loff_t *ppos,
ocfs2_set_next_iovec(&cur_iov, &iov_offset, o_direct_written);
do {
bp.b_cur_off = iov_offset;
bp.b_cur_iov = cur_iov;
pos = *ppos;
page = ocfs2_get_write_source(&bp, cur_iov, iov_offset);
if (IS_ERR(page)) {
ret = PTR_ERR(page);
user_page = ocfs2_get_write_source(&buf, cur_iov, iov_offset);
if (IS_ERR(user_page)) {
ret = PTR_ERR(user_page);
goto out;
}
copied = ocfs2_buffered_write_cluster(file, *ppos, count,
ocfs2_map_and_write_user_data,
&bp);
/* Stay within our page boundaries */
bytes = min((PAGE_CACHE_SIZE - ((unsigned long)pos & ~PAGE_CACHE_MASK)),
(PAGE_CACHE_SIZE - ((unsigned long)buf & ~PAGE_CACHE_MASK)));
/* Stay within the vector boundary */
bytes = min_t(size_t, bytes, cur_iov->iov_len - iov_offset);
/* Stay within count */
bytes = min(bytes, count);
ocfs2_put_write_source(&bp, page);
page = NULL;
ret = ocfs2_write_begin(file, file->f_mapping, pos, bytes, 0,
&page, &fsdata);
if (ret) {
mlog_errno(ret);
goto out;
}
dst = kmap_atomic(page, KM_USER0);
memcpy(dst + (pos & (PAGE_CACHE_SIZE - 1)), buf, bytes);
kunmap_atomic(dst, KM_USER0);
flush_dcache_page(page);
ocfs2_put_write_source(user_page);
copied = ocfs2_write_end(file, file->f_mapping, pos, bytes,
bytes, page, fsdata);
if (copied < 0) {
mlog_errno(copied);
ret = copied;
@ -1415,7 +1434,7 @@ static ssize_t ocfs2_file_buffered_write(struct file *file, loff_t *ppos,
}
total += copied;
*ppos = *ppos + copied;
*ppos = pos + copied;
count -= copied;
ocfs2_set_next_iovec(&cur_iov, &iov_offset, copied);
@ -1585,52 +1604,46 @@ static int ocfs2_splice_write_actor(struct pipe_inode_info *pipe,
struct pipe_buffer *buf,
struct splice_desc *sd)
{
int ret, count, total = 0;
int ret, count;
ssize_t copied = 0;
struct ocfs2_splice_write_priv sp;
struct file *file = sd->u.file;
unsigned int offset;
struct page *page = NULL;
void *fsdata;
char *src, *dst;
ret = buf->ops->confirm(pipe, buf);
if (ret)
goto out;
sp.s_sd = sd;
sp.s_buf = buf;
sp.s_pipe = pipe;
sp.s_offset = sd->pos & ~PAGE_CACHE_MASK;
sp.s_buf_offset = buf->offset;
offset = sd->pos & ~PAGE_CACHE_MASK;
count = sd->len;
if (count + sp.s_offset > PAGE_CACHE_SIZE)
count = PAGE_CACHE_SIZE - sp.s_offset;
if (count + offset > PAGE_CACHE_SIZE)
count = PAGE_CACHE_SIZE - offset;
do {
/*
* splice wants us to copy up to one page at a
* time. For pagesize > cluster size, this means we
* might enter ocfs2_buffered_write_cluster() more
* than once, so keep track of our progress here.
*/
copied = ocfs2_buffered_write_cluster(sd->u.file,
(loff_t)sd->pos + total,
count,
ocfs2_map_and_write_splice_data,
&sp);
if (copied < 0) {
mlog_errno(copied);
ret = copied;
goto out;
}
ret = ocfs2_write_begin(file, file->f_mapping, sd->pos, count, 0,
&page, &fsdata);
if (ret) {
mlog_errno(ret);
goto out;
}
count -= copied;
sp.s_offset += copied;
sp.s_buf_offset += copied;
total += copied;
} while (count);
src = buf->ops->map(pipe, buf, 1);
dst = kmap_atomic(page, KM_USER1);
memcpy(dst + offset, src + buf->offset, count);
kunmap_atomic(page, KM_USER1);
buf->ops->unmap(pipe, buf, src);
ret = 0;
copied = ocfs2_write_end(file, file->f_mapping, sd->pos, count, count,
page, fsdata);
if (copied < 0) {
mlog_errno(copied);
ret = copied;
goto out;
}
out:
return total ? total : ret;
return copied ? copied : ret;
}
static ssize_t __ocfs2_file_splice_write(struct pipe_inode_info *pipe,