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export generic_perform_write(), start getting rid of generic_file_buffer_write()

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2014-02-11 21:34:08 -05:00
parent 5cb6c6c7eb
commit 3b93f911d5
2 changed files with 23 additions and 16 deletions
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2
include/linux/fs.h
View File

@ -48,6 +48,7 @@ struct cred;
struct swap_info_struct;
struct seq_file;
struct workqueue_struct;
struct iov_iter;
extern void __init inode_init(void);
extern void __init inode_init_early(void);
@ -2396,6 +2397,7 @@ extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, un
extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *,
unsigned long *, loff_t, size_t, size_t);
extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);
extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *,
unsigned long, loff_t, size_t, ssize_t);
extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);

37
mm/filemap.c
View File

@ -2092,7 +2092,7 @@ found:
}
EXPORT_SYMBOL(grab_cache_page_write_begin);
static ssize_t generic_perform_write(struct file *file,
ssize_t generic_perform_write(struct file *file,
struct iov_iter *i, loff_t pos)
{
struct address_space *mapping = file->f_mapping;
@ -2180,6 +2180,7 @@ again:
return written ? written : status;
}
EXPORT_SYMBOL(generic_perform_write);
ssize_t
generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
@ -2230,8 +2231,10 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
size_t count; /* after file limit checks */
struct inode *inode = mapping->host;
loff_t pos = iocb->ki_pos;
ssize_t written;
ssize_t written = 0;
ssize_t err;
ssize_t status;
struct iov_iter from;
ocount = 0;
err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
@ -2242,8 +2245,6 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
/* We can write back this queue in page reclaim */
current->backing_dev_info = mapping->backing_dev_info;
written = 0;
err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
if (err)
goto out;
@ -2259,44 +2260,47 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
if (err)
goto out;
iov_iter_init(&from, iov, nr_segs, count, 0);
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
if (unlikely(file->f_flags & O_DIRECT)) {
loff_t endbyte;
ssize_t written_buffered;
written = generic_file_direct_write(iocb, iov, &nr_segs, pos,
written = generic_file_direct_write(iocb, iov, &from.nr_segs, pos,
count, ocount);
if (written < 0 || written == count)
goto out;
iov_iter_advance(&from, written);
/*
* direct-io write to a hole: fall through to buffered I/O
* for completing the rest of the request.
*/
pos += written;
count -= written;
written_buffered = generic_file_buffered_write(iocb, iov,
nr_segs, pos, count, written);
status = generic_perform_write(file, &from, pos);
/*
* If generic_file_buffered_write() retuned a synchronous error
* If generic_perform_write() returned a synchronous error
* then we want to return the number of bytes which were
* direct-written, or the error code if that was zero. Note
* that this differs from normal direct-io semantics, which
* will return -EFOO even if some bytes were written.
*/
if (written_buffered < 0) {
err = written_buffered;
if (unlikely(status < 0) && !written) {
err = status;
goto out;
}
iocb->ki_pos = pos + status;
/*
* We need to ensure that the page cache pages are written to
* disk and invalidated to preserve the expected O_DIRECT
* semantics.
*/
endbyte = pos + written_buffered - written - 1;
endbyte = pos + status - 1;
err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
if (err == 0) {
written = written_buffered;
written += status;
invalidate_mapping_pages(mapping,
pos >> PAGE_CACHE_SHIFT,
endbyte >> PAGE_CACHE_SHIFT);
@ -2307,8 +2311,9 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
*/
}
} else {
written = generic_file_buffered_write(iocb, iov, nr_segs,
pos, count, written);
written = generic_perform_write(file, &from, pos);
if (likely(written >= 0))
iocb->ki_pos = pos + written;
}
out:
current->backing_dev_info = NULL;