cifs: convert async read code to use pages array without kmapping
Replace the "marshal_iov" function with a "read_into_pages" function.
That function will copy the read data off the socket and into the
pages array, kmapping and reading pages one at a time.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 6eaf482..f3f1b10 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2566,63 +2566,57 @@
{
struct cifs_readdata *rdata = container_of(work,
struct cifs_readdata, work);
- unsigned int i;
-
- /* if the result is non-zero then the pages weren't kmapped */
- if (rdata->result == 0) {
- for (i = 0; i < rdata->nr_pages; i++)
- kunmap(rdata->pages[i]);
- }
complete(&rdata->done);
kref_put(&rdata->refcount, cifs_uncached_readdata_release);
}
static int
-cifs_uncached_read_marshal_iov(struct cifs_readdata *rdata,
- unsigned int remaining)
+cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
+ struct cifs_readdata *rdata, unsigned int len)
{
- int len = 0;
+ int total_read = 0, result = 0;
unsigned int i;
unsigned int nr_pages = rdata->nr_pages;
+ struct kvec iov;
- rdata->nr_iov = 1;
+ rdata->tailsz = PAGE_SIZE;
for (i = 0; i < nr_pages; i++) {
struct page *page = rdata->pages[i];
- if (remaining >= PAGE_SIZE) {
+ if (len >= PAGE_SIZE) {
/* enough data to fill the page */
- rdata->iov[rdata->nr_iov].iov_base = kmap(page);
- rdata->iov[rdata->nr_iov].iov_len = PAGE_SIZE;
- cFYI(1, "%u: idx=%lu iov_base=%p iov_len=%zu",
- rdata->nr_iov, page->index,
- rdata->iov[rdata->nr_iov].iov_base,
- rdata->iov[rdata->nr_iov].iov_len);
- ++rdata->nr_iov;
- len += PAGE_SIZE;
- remaining -= PAGE_SIZE;
- } else if (remaining > 0) {
+ iov.iov_base = kmap(page);
+ iov.iov_len = PAGE_SIZE;
+ cFYI(1, "%u: iov_base=%p iov_len=%zu",
+ i, iov.iov_base, iov.iov_len);
+ len -= PAGE_SIZE;
+ } else if (len > 0) {
/* enough for partial page, fill and zero the rest */
- rdata->iov[rdata->nr_iov].iov_base = kmap(page);
- rdata->iov[rdata->nr_iov].iov_len = remaining;
- cFYI(1, "%u: idx=%lu iov_base=%p iov_len=%zu",
- rdata->nr_iov, page->index,
- rdata->iov[rdata->nr_iov].iov_base,
- rdata->iov[rdata->nr_iov].iov_len);
- memset(rdata->iov[rdata->nr_iov].iov_base + remaining,
- '\0', PAGE_SIZE - remaining);
- ++rdata->nr_iov;
- len += remaining;
- remaining = 0;
+ iov.iov_base = kmap(page);
+ iov.iov_len = len;
+ cFYI(1, "%u: iov_base=%p iov_len=%zu",
+ i, iov.iov_base, iov.iov_len);
+ memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
+ rdata->tailsz = len;
+ len = 0;
} else {
/* no need to hold page hostage */
rdata->pages[i] = NULL;
rdata->nr_pages--;
put_page(page);
+ continue;
}
+
+ result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
+ kunmap(page);
+ if (result < 0)
+ break;
+
+ total_read += result;
}
- return len;
+ return total_read > 0 ? total_read : result;
}
static ssize_t
@@ -2685,7 +2679,8 @@
rdata->offset = offset;
rdata->bytes = cur_len;
rdata->pid = pid;
- rdata->marshal_iov = cifs_uncached_read_marshal_iov;
+ rdata->pagesz = PAGE_SIZE;
+ rdata->read_into_pages = cifs_uncached_read_into_pages;
rc = cifs_retry_async_readv(rdata);
error:
@@ -2935,7 +2930,6 @@
lru_cache_add_file(page);
if (rdata->result == 0) {
- kunmap(page);
flush_dcache_page(page);
SetPageUptodate(page);
}
@@ -2952,47 +2946,42 @@
}
static int
-cifs_readpages_marshal_iov(struct cifs_readdata *rdata, unsigned int remaining)
+cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
+ struct cifs_readdata *rdata, unsigned int len)
{
- int len = 0;
+ int total_read = 0, result = 0;
unsigned int i;
u64 eof;
pgoff_t eof_index;
unsigned int nr_pages = rdata->nr_pages;
+ struct kvec iov;
/* determine the eof that the server (probably) has */
eof = CIFS_I(rdata->mapping->host)->server_eof;
eof_index = eof ? (eof - 1) >> PAGE_CACHE_SHIFT : 0;
cFYI(1, "eof=%llu eof_index=%lu", eof, eof_index);
- rdata->nr_iov = 1;
+ rdata->tailsz = PAGE_CACHE_SIZE;
for (i = 0; i < nr_pages; i++) {
struct page *page = rdata->pages[i];
- if (remaining >= PAGE_CACHE_SIZE) {
+ if (len >= PAGE_CACHE_SIZE) {
/* enough data to fill the page */
- rdata->iov[rdata->nr_iov].iov_base = kmap(page);
- rdata->iov[rdata->nr_iov].iov_len = PAGE_CACHE_SIZE;
+ iov.iov_base = kmap(page);
+ iov.iov_len = PAGE_CACHE_SIZE;
cFYI(1, "%u: idx=%lu iov_base=%p iov_len=%zu",
- rdata->nr_iov, page->index,
- rdata->iov[rdata->nr_iov].iov_base,
- rdata->iov[rdata->nr_iov].iov_len);
- ++rdata->nr_iov;
- len += PAGE_CACHE_SIZE;
- remaining -= PAGE_CACHE_SIZE;
- } else if (remaining > 0) {
+ i, page->index, iov.iov_base, iov.iov_len);
+ len -= PAGE_CACHE_SIZE;
+ } else if (len > 0) {
/* enough for partial page, fill and zero the rest */
- rdata->iov[rdata->nr_iov].iov_base = kmap(page);
- rdata->iov[rdata->nr_iov].iov_len = remaining;
+ iov.iov_base = kmap(page);
+ iov.iov_len = len;
cFYI(1, "%u: idx=%lu iov_base=%p iov_len=%zu",
- rdata->nr_iov, page->index,
- rdata->iov[rdata->nr_iov].iov_base,
- rdata->iov[rdata->nr_iov].iov_len);
- memset(rdata->iov[rdata->nr_iov].iov_base + remaining,
- '\0', PAGE_CACHE_SIZE - remaining);
- ++rdata->nr_iov;
- len += remaining;
- remaining = 0;
+ i, page->index, iov.iov_base, iov.iov_len);
+ memset(iov.iov_base + len,
+ '\0', PAGE_CACHE_SIZE - len);
+ rdata->tailsz = len;
+ len = 0;
} else if (page->index > eof_index) {
/*
* The VFS will not try to do readahead past the
@@ -3010,6 +2999,7 @@
page_cache_release(page);
rdata->pages[i] = NULL;
rdata->nr_pages--;
+ continue;
} else {
/* no need to hold page hostage */
lru_cache_add_file(page);
@@ -3017,10 +3007,18 @@
page_cache_release(page);
rdata->pages[i] = NULL;
rdata->nr_pages--;
+ continue;
}
+
+ result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
+ kunmap(page);
+ if (result < 0)
+ break;
+
+ total_read += result;
}
- return len;
+ return total_read > 0 ? total_read : result;
}
static int cifs_readpages(struct file *file, struct address_space *mapping,
@@ -3144,7 +3142,8 @@
rdata->offset = offset;
rdata->bytes = bytes;
rdata->pid = pid;
- rdata->marshal_iov = cifs_readpages_marshal_iov;
+ rdata->pagesz = PAGE_CACHE_SIZE;
+ rdata->read_into_pages = cifs_readpages_read_into_pages;
list_for_each_entry_safe(page, tpage, &tmplist, lru) {
list_del(&page->lru);