CIFS: implement cifs_writepages to perform multi-page I/O

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This commit is contained in:
Steve French 2005-10-05 14:50:29 -07:00
parent 6148a742b2
commit 37c0eb4677
2 changed files with 190 additions and 11 deletions

View File

@ -21,11 +21,14 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/fs.h>
#include <linux/backing-dev.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/mpage.h>
#include <linux/pagemap.h>
#include <linux/pagevec.h>
#include <linux/smp_lock.h>
#include <linux/writeback.h>
#include <asm/div64.h>
#include "cifsfs.h"
#include "cifspdu.h"
@ -916,6 +919,16 @@ static struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode)
((open_file->pfile->f_flags & O_RDWR) ||
(open_file->pfile->f_flags & O_WRONLY))) {
read_unlock(&GlobalSMBSeslock);
if(open_file->invalidHandle) {
rc = cifs_reopen_file(cifs_inode->vfs_inode,
open_file->pfile, FALSE);
/* if it fails, try another handle - might be */
/* dangerous to hold up writepages with retry */
if(rc) {
read_lock(&GlobalSMBSeslock);
continue;
}
}
return open_file;
}
}
@ -982,20 +995,181 @@ static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
return rc;
}
#if 0
#ifdef CONFIG_CIFS_EXPERIMENTAL
static int cifs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
struct writeback_control *wbc)
{
int rc = -EFAULT;
struct backing_dev_info *bdi = mapping->backing_dev_info;
unsigned int bytes_to_write;
unsigned int bytes_written;
struct cifs_sb_info *cifs_sb;
int done = 0;
pgoff_t end = -1;
pgoff_t index;
int is_range = 0;
struct kvec iov[32];
int n_iov = 0;
pgoff_t next;
int nr_pages;
__u64 offset = 0;
struct cifsFileInfo *open_file = NULL;
struct page *page;
struct pagevec pvec;
int rc = 0;
int scanned = 0;
int xid;
cifs_sb = CIFS_SB(mapping->host->i_sb);
/*
* If wsize is smaller that the page cache size, default to writing
* one page at a time via cifs_writepage
*/
if (cifs_sb->wsize < PAGE_CACHE_SIZE)
return generic_writepages(mapping, wbc);
/*
* BB: Is this meaningful for a non-block-device file system?
* If it is, we should test it again after we do I/O
*/
if (wbc->nonblocking && bdi_write_congested(bdi)) {
wbc->encountered_congestion = 1;
return 0;
}
xid = GetXid();
/* Find contiguous pages then iterate through repeating
call 16K write then Setpageuptodate or if LARGE_WRITE_X
support then send larger writes via kevec so as to eliminate
a memcpy */
pagevec_init(&pvec, 0);
if (wbc->sync_mode == WB_SYNC_NONE)
index = mapping->writeback_index; /* Start from prev offset */
else {
index = 0;
scanned = 1;
}
if (wbc->start || wbc->end) {
index = wbc->start >> PAGE_CACHE_SHIFT;
end = wbc->end >> PAGE_CACHE_SHIFT;
is_range = 1;
scanned = 1;
}
retry:
while (!done && (index <= end) &&
(nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
PAGECACHE_TAG_DIRTY,
min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1))) {
int first;
unsigned int i;
if (!open_file) {
open_file = find_writable_file(CIFS_I(mapping->host));
if (!open_file) {
pagevec_release(&pvec);
cERROR(1, ("No writable handles for inode"));
return -EIO;
}
}
first = -1;
next = 0;
n_iov = 0;
bytes_to_write = 0;
for (i = 0; i < nr_pages; i++) {
page = pvec.pages[i];
/*
* At this point we hold neither mapping->tree_lock nor
* lock on the page itself: the page may be truncated or
* invalidated (changing page->mapping to NULL), or even
* swizzled back from swapper_space to tmpfs file
* mapping
*/
if (first < 0)
lock_page(page);
else if (TestSetPageLocked(page))
break;
if (unlikely(page->mapping != mapping)) {
unlock_page(page);
break;
}
if (unlikely(is_range) && (page->index > end)) {
done = 1;
unlock_page(page);
break;
}
if (next && (page->index != next)) {
/* Not next consecutive page */
unlock_page(page);
break;
}
if (wbc->sync_mode != WB_SYNC_NONE)
wait_on_page_writeback(page);
if (PageWriteback(page) ||
!test_clear_page_dirty(page)) {
unlock_page(page);
break;
}
/*
* BB can we get rid of this? pages are held by pvec
*/
page_cache_get(page);
/* reserve iov[0] for the smb header */
n_iov++;
iov[n_iov].iov_base = kmap(page);
iov[n_iov].iov_len = PAGE_CACHE_SIZE;
bytes_to_write += PAGE_CACHE_SIZE;
if (first < 0) {
first = i;
offset = page_offset(page);
}
next = page->index + 1;
if (bytes_to_write + PAGE_CACHE_SIZE > cifs_sb->wsize)
break;
}
if (n_iov) {
rc = CIFSSMBWrite2(xid, cifs_sb->tcon,
open_file->netfid, bytes_to_write,
offset, &bytes_written, iov, n_iov,
1);
if (rc || bytes_written < bytes_to_write) {
cERROR(1,("CIFSSMBWrite2 returned %d, written = %x",
rc, bytes_written));
set_bit(AS_EIO, &mapping->flags);
SetPageError(page);
}
for (i = 0; i < n_iov; i++) {
page = pvec.pages[first + i];
kunmap(page);
unlock_page(page);
page_cache_release(page);
}
if ((wbc->nr_to_write -= n_iov) <= 0)
done = 1;
index = next;
}
pagevec_release(&pvec);
}
if (!scanned && !done) {
/*
* We hit the last page and there is more work to be done: wrap
* back to the start of the file
*/
scanned = 1;
index = 0;
goto retry;
}
if (!is_range)
mapping->writeback_index = index;
FreeXid(xid);
return rc;
}
#endif
@ -1635,6 +1809,9 @@ struct address_space_operations cifs_addr_ops = {
.readpage = cifs_readpage,
.readpages = cifs_readpages,
.writepage = cifs_writepage,
#ifdef CONFIG_CIFS_EXPERIMENTAL
.writepages = cifs_writepages,
#endif
.prepare_write = cifs_prepare_write,
.commit_write = cifs_commit_write,
.set_page_dirty = __set_page_dirty_nobuffers,

View File

@ -395,7 +395,7 @@ SendReceive2(const unsigned int xid, struct cifsSesInfo *ses,
if (long_op == -1)
goto cifs_no_response_exit2;
else if (long_op == 2) /* writes past end of file can take loong time */
timeout = 300 * HZ;
timeout = 180 * HZ;
else if (long_op == 1)
timeout = 45 * HZ; /* should be greater than
servers oplock break timeout (about 43 seconds) */
@ -431,7 +431,8 @@ SendReceive2(const unsigned int xid, struct cifsSesInfo *ses,
spin_unlock(&GlobalMid_Lock);
receive_len = midQ->resp_buf->smb_buf_length;
} else {
cERROR(1,("No response buffer"));
cERROR(1,("No response to cmd %d mid %d",
midQ->command, midQ->mid));
if(midQ->midState == MID_REQUEST_SUBMITTED) {
if(ses->server->tcpStatus == CifsExiting)
rc = -EHOSTDOWN;
@ -646,7 +647,7 @@ SendReceive(const unsigned int xid, struct cifsSesInfo *ses,
if (long_op == -1)
goto cifs_no_response_exit;
else if (long_op == 2) /* writes past end of file can take loong time */
timeout = 300 * HZ;
timeout = 180 * HZ;
else if (long_op == 1)
timeout = 45 * HZ; /* should be greater than
servers oplock break timeout (about 43 seconds) */
@ -682,7 +683,8 @@ SendReceive(const unsigned int xid, struct cifsSesInfo *ses,
spin_unlock(&GlobalMid_Lock);
receive_len = midQ->resp_buf->smb_buf_length;
} else {
cERROR(1,("No response buffer"));
cERROR(1,("No response for cmd %d mid %d",
midQ->command, midQ->mid));
if(midQ->midState == MID_REQUEST_SUBMITTED) {
if(ses->server->tcpStatus == CifsExiting)
rc = -EHOSTDOWN;