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cifs: convert cifs_iovec_write to use async writes 

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
This commit is contained in:
Jeff Layton 2012-03-23 14:40:56 -04:00
parent 597b027f69
commit da82f7e755
3 changed files with 147 additions and 90 deletions
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2
fs/cifs/cifsproto.h
View File

@ -483,6 +483,8 @@ int cifs_async_readv(struct cifs_readdata *rdata);
/* asynchronous write support */
struct cifs_writedata {
struct kref refcount;
struct list_head list;
struct completion done;
enum writeback_sync_modes sync_mode;
struct work_struct work;
struct cifsFileInfo *cfile;

4
fs/cifs/cifssmb.c
View File

@ -2081,8 +2081,10 @@ cifs_writedata_alloc(unsigned int nr_pages, work_func_t complete)
wdata = kzalloc(sizeof(*wdata) +
sizeof(struct page *) * (nr_pages - 1), GFP_NOFS);
if (wdata != NULL) {
INIT_WORK(&wdata->work, complete);
kref_init(&wdata->refcount);
INIT_LIST_HEAD(&wdata->list);
init_completion(&wdata->done);
INIT_WORK(&wdata->work, complete);
}
return wdata;
}

231
fs/cifs/file.c
View File

@ -2106,24 +2106,79 @@ size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
return num_pages;
}
static void
cifs_uncached_marshal_iov(struct kvec *iov, struct cifs_writedata *wdata)
{
int i;
size_t bytes = wdata->bytes;
/* marshal up the pages into iov array */
for (i = 0; i < wdata->nr_pages; i++) {
iov[i + 1].iov_len = min(bytes, PAGE_SIZE);
iov[i + 1].iov_base = kmap(wdata->pages[i]);
bytes -= iov[i + 1].iov_len;
}
}
static void
cifs_uncached_writev_complete(struct work_struct *work)
{
int i;
struct cifs_writedata *wdata = container_of(work,
struct cifs_writedata, work);
struct inode *inode = wdata->cfile->dentry->d_inode;
struct cifsInodeInfo *cifsi = CIFS_I(inode);
spin_lock(&inode->i_lock);
cifs_update_eof(cifsi, wdata->offset, wdata->bytes);
if (cifsi->server_eof > inode->i_size)
i_size_write(inode, cifsi->server_eof);
spin_unlock(&inode->i_lock);
complete(&wdata->done);
if (wdata->result != -EAGAIN) {
for (i = 0; i < wdata->nr_pages; i++)
put_page(wdata->pages[i]);
}
kref_put(&wdata->refcount, cifs_writedata_release);
}
/* attempt to send write to server, retry on any -EAGAIN errors */
static int
cifs_uncached_retry_writev(struct cifs_writedata *wdata)
{
int rc;
do {
if (wdata->cfile->invalidHandle) {
rc = cifs_reopen_file(wdata->cfile, false);
if (rc != 0)
continue;
}
rc = cifs_async_writev(wdata);
} while (rc == -EAGAIN);
return rc;
}
static ssize_t
cifs_iovec_write(struct file *file, const struct iovec *iov,
unsigned long nr_segs, loff_t *poffset)
{
unsigned int written;
unsigned long num_pages, npages, i;
unsigned long nr_pages, i;
size_t copied, len, cur_len;
ssize_t total_written = 0;
struct kvec *to_send;
struct page **pages;
loff_t offset = *poffset;
struct iov_iter it;
struct inode *inode;
struct cifsFileInfo *open_file;
struct cifs_tcon *pTcon;
struct cifs_tcon *tcon;
struct cifs_sb_info *cifs_sb;
struct cifs_io_parms io_parms;
int xid, rc;
__u32 pid;
struct cifs_writedata *wdata, *tmp;
struct list_head wdata_list;
int rc;
pid_t pid;
len = iov_length(iov, nr_segs);
if (!len)
@ -2133,105 +2188,103 @@ cifs_iovec_write(struct file *file, const struct iovec *iov,
if (rc)
return rc;
INIT_LIST_HEAD(&wdata_list);
cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
num_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
pages = kmalloc(sizeof(struct pages *)*num_pages, GFP_KERNEL);
if (!pages)
return -ENOMEM;
to_send = kmalloc(sizeof(struct kvec)*(num_pages + 1), GFP_KERNEL);
if (!to_send) {
kfree(pages);
return -ENOMEM;
}
rc = cifs_write_allocate_pages(pages, num_pages);
if (rc) {
kfree(pages);
kfree(to_send);
return rc;
}
xid = GetXid();
open_file = file->private_data;
tcon = tlink_tcon(open_file->tlink);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
pid = open_file->pid;
else
pid = current->tgid;
pTcon = tlink_tcon(open_file->tlink);
inode = file->f_path.dentry->d_inode;
iov_iter_init(&it, iov, nr_segs, len, 0);
npages = num_pages;
do {
size_t save_len = cur_len;
for (i = 0; i < npages; i++) {
copied = min_t(const size_t, cur_len, PAGE_CACHE_SIZE);
copied = iov_iter_copy_from_user(pages[i], &it, 0,
copied);
cur_len -= copied;
iov_iter_advance(&it, copied);
to_send[i+1].iov_base = kmap(pages[i]);
to_send[i+1].iov_len = copied;
}
size_t save_len;
cur_len = save_len - cur_len;
do {
if (open_file->invalidHandle) {
rc = cifs_reopen_file(open_file, false);
if (rc != 0)
break;
}
io_parms.netfid = open_file->netfid;
io_parms.pid = pid;
io_parms.tcon = pTcon;
io_parms.offset = *poffset;
io_parms.length = cur_len;
rc = CIFSSMBWrite2(xid, &io_parms, &written, to_send,
npages, 0);
} while (rc == -EAGAIN);
for (i = 0; i < npages; i++)
kunmap(pages[i]);
if (written) {
len -= written;
total_written += written;
spin_lock(&inode->i_lock);
cifs_update_eof(CIFS_I(inode), *poffset, written);
spin_unlock(&inode->i_lock);
*poffset += written;
} else if (rc < 0) {
if (!total_written)
total_written = rc;
nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
wdata = cifs_writedata_alloc(nr_pages,
cifs_uncached_writev_complete);
if (!wdata) {
rc = -ENOMEM;
break;
}
/* get length and number of kvecs of the next write */
npages = get_numpages(cifs_sb->wsize, len, &cur_len);
rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
if (rc) {
kfree(wdata);
break;
}
save_len = cur_len;
for (i = 0; i < nr_pages; i++) {
copied = min_t(const size_t, cur_len, PAGE_SIZE);
copied = iov_iter_copy_from_user(wdata->pages[i], &it,
0, copied);
cur_len -= copied;
iov_iter_advance(&it, copied);
}
cur_len = save_len - cur_len;
wdata->sync_mode = WB_SYNC_ALL;
wdata->nr_pages = nr_pages;
wdata->offset = (__u64)offset;
wdata->cfile = cifsFileInfo_get(open_file);
wdata->pid = pid;
wdata->bytes = cur_len;
wdata->marshal_iov = cifs_uncached_marshal_iov;
rc = cifs_uncached_retry_writev(wdata);
if (rc) {
kref_put(&wdata->refcount, cifs_writedata_release);
break;
}
list_add_tail(&wdata->list, &wdata_list);
offset += cur_len;
len -= cur_len;
} while (len > 0);
if (total_written > 0) {
spin_lock(&inode->i_lock);
if (*poffset > inode->i_size)
i_size_write(inode, *poffset);
spin_unlock(&inode->i_lock);
/*
* If at least one write was successfully sent, then discard any rc
* value from the later writes. If the other write succeeds, then
* we'll end up returning whatever was written. If it fails, then
* we'll get a new rc value from that.
*/
if (!list_empty(&wdata_list))
rc = 0;
/*
* Wait for and collect replies for any successful sends in order of
* increasing offset. Once an error is hit or we get a fatal signal
* while waiting, then return without waiting for any more replies.
*/
restart_loop:
list_for_each_entry_safe(wdata, tmp, &wdata_list, list) {
if (!rc) {
/* FIXME: freezable too? */
rc = wait_for_completion_killable(&wdata->done);
if (rc)
rc = -EINTR;
else if (wdata->result)
rc = wdata->result;
else
total_written += wdata->bytes;
/* resend call if it's a retryable error */
if (rc == -EAGAIN) {
rc = cifs_uncached_retry_writev(wdata);
goto restart_loop;
}
}
list_del_init(&wdata->list);
kref_put(&wdata->refcount, cifs_writedata_release);
}
cifs_stats_bytes_written(pTcon, total_written);
mark_inode_dirty_sync(inode);
if (total_written > 0)
*poffset += total_written;
for (i = 0; i < num_pages; i++)
put_page(pages[i]);
kfree(to_send);
kfree(pages);
FreeXid(xid);
return total_written;
cifs_stats_bytes_written(tcon, total_written);
return total_written ? total_written : (ssize_t)rc;
}
ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov,