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cifs: turn the pages list in cifs_readdata into an array
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We'll need an array to put into a smb_rqst, so convert this into an array
instead of (ab)using the lru list_head.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
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Jeff Layton authored and Steve French committed Sep 25, 2012
1 parent f4e49cd commit c5fab6f
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Showing 2 changed files with 52 additions and 38 deletions.
3 changes: 2 additions & 1 deletion fs/cifs/cifsglob.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -977,12 +977,13 @@ struct cifs_readdata {
unsigned int bytes;
pid_t pid;
int result;
struct list_head pages;
struct work_struct work;
int (*marshal_iov) (struct cifs_readdata *rdata,
unsigned int remaining);
unsigned int nr_iov;
struct kvec *iov;
unsigned int nr_pages;
struct page *pages[];
};

struct cifs_writedata;
Expand Down
87 changes: 50 additions & 37 deletions fs/cifs/file.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2419,13 +2419,13 @@ cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
if (!iov)
return (struct cifs_readdata *)iov;

rdata = kzalloc(sizeof(*rdata), GFP_KERNEL);
rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
GFP_KERNEL);
if (rdata != NULL) {
kref_init(&rdata->refcount);
INIT_LIST_HEAD(&rdata->list);
init_completion(&rdata->done);
INIT_WORK(&rdata->work, complete);
INIT_LIST_HEAD(&rdata->pages);
rdata->iov = iov;
} else {
kfree(iov);
Expand All @@ -2448,25 +2448,25 @@ cifs_readdata_release(struct kref *refcount)
}

static int
cifs_read_allocate_pages(struct list_head *list, unsigned int npages)
cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
{
int rc = 0;
struct page *page, *tpage;
struct page *page;
unsigned int i;

for (i = 0; i < npages; i++) {
for (i = 0; i < nr_pages; i++) {
page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
if (!page) {
rc = -ENOMEM;
break;
}
list_add(&page->lru, list);
rdata->pages[i] = page;
}

if (rc) {
list_for_each_entry_safe(page, tpage, list, lru) {
list_del(&page->lru);
put_page(page);
for (i = 0; i < nr_pages; i++) {
put_page(rdata->pages[i]);
rdata->pages[i] = NULL;
}
}
return rc;
Expand All @@ -2475,13 +2475,13 @@ cifs_read_allocate_pages(struct list_head *list, unsigned int npages)
static void
cifs_uncached_readdata_release(struct kref *refcount)
{
struct page *page, *tpage;
struct cifs_readdata *rdata = container_of(refcount,
struct cifs_readdata, refcount);
unsigned int i;

list_for_each_entry_safe(page, tpage, &rdata->pages, lru) {
list_del(&page->lru);
put_page(page);
for (i = 0; i < rdata->nr_pages; i++) {
put_page(rdata->pages[i]);
rdata->pages[i] = NULL;
}
cifs_readdata_release(refcount);
}
Expand Down Expand Up @@ -2525,17 +2525,18 @@ cifs_readdata_to_iov(struct cifs_readdata *rdata, const struct iovec *iov,
int rc = 0;
struct iov_iter ii;
size_t pos = rdata->offset - offset;
struct page *page, *tpage;
ssize_t remaining = rdata->bytes;
unsigned char *pdata;
unsigned int i;

/* set up iov_iter and advance to the correct offset */
iov_iter_init(&ii, iov, nr_segs, iov_length(iov, nr_segs), 0);
iov_iter_advance(&ii, pos);

*copied = 0;
list_for_each_entry_safe(page, tpage, &rdata->pages, lru) {
for (i = 0; i < rdata->nr_pages; i++) {
ssize_t copy;
struct page *page = rdata->pages[i];

/* copy a whole page or whatever's left */
copy = min_t(ssize_t, remaining, PAGE_SIZE);
Expand All @@ -2555,9 +2556,6 @@ cifs_readdata_to_iov(struct cifs_readdata *rdata, const struct iovec *iov,
iov_iter_advance(&ii, copy);
}
}

list_del(&page->lru);
put_page(page);
}

return rc;
Expand All @@ -2568,13 +2566,12 @@ cifs_uncached_readv_complete(struct work_struct *work)
{
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) {
struct page *page;

list_for_each_entry(page, &rdata->pages, lru)
kunmap(page);
for (i = 0; i < rdata->nr_pages; i++)
kunmap(rdata->pages[i]);
}

complete(&rdata->done);
Expand All @@ -2586,10 +2583,13 @@ cifs_uncached_read_marshal_iov(struct cifs_readdata *rdata,
unsigned int remaining)
{
int len = 0;
struct page *page, *tpage;
unsigned int i;
unsigned int nr_pages = rdata->nr_pages;

rdata->nr_iov = 1;
list_for_each_entry_safe(page, tpage, &rdata->pages, lru) {
for (i = 0; i < nr_pages; i++) {
struct page *page = rdata->pages[i];

if (remaining >= PAGE_SIZE) {
/* enough data to fill the page */
rdata->iov[rdata->nr_iov].iov_base = kmap(page);
Expand All @@ -2616,7 +2616,8 @@ cifs_uncached_read_marshal_iov(struct cifs_readdata *rdata,
remaining = 0;
} else {
/* no need to hold page hostage */
list_del(&page->lru);
rdata->pages[i] = NULL;
rdata->nr_pages--;
put_page(page);
}
}
Expand Down Expand Up @@ -2675,11 +2676,12 @@ cifs_iovec_read(struct file *file, const struct iovec *iov,
goto error;
}

rc = cifs_read_allocate_pages(&rdata->pages, npages);
rc = cifs_read_allocate_pages(rdata, npages);
if (rc)
goto error;

rdata->cfile = cifsFileInfo_get(open_file);
rdata->nr_pages = npages;
rdata->offset = offset;
rdata->bytes = cur_len;
rdata->pid = pid;
Expand Down Expand Up @@ -2923,12 +2925,13 @@ int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
static void
cifs_readv_complete(struct work_struct *work)
{
unsigned int i;
struct cifs_readdata *rdata = container_of(work,
struct cifs_readdata, work);
struct page *page, *tpage;

list_for_each_entry_safe(page, tpage, &rdata->pages, lru) {
list_del(&page->lru);
for (i = 0; i < rdata->nr_pages; i++) {
struct page *page = rdata->pages[i];

lru_cache_add_file(page);

if (rdata->result == 0) {
Expand All @@ -2943,6 +2946,7 @@ cifs_readv_complete(struct work_struct *work)
cifs_readpage_to_fscache(rdata->mapping->host, page);

page_cache_release(page);
rdata->pages[i] = NULL;
}
kref_put(&rdata->refcount, cifs_readdata_release);
}
Expand All @@ -2951,17 +2955,20 @@ static int
cifs_readpages_marshal_iov(struct cifs_readdata *rdata, unsigned int remaining)
{
int len = 0;
struct page *page, *tpage;
unsigned int i;
u64 eof;
pgoff_t eof_index;
unsigned int nr_pages = rdata->nr_pages;

/* 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;
list_for_each_entry_safe(page, tpage, &rdata->pages, lru) {
for (i = 0; i < nr_pages; i++) {
struct page *page = rdata->pages[i];

if (remaining >= PAGE_CACHE_SIZE) {
/* enough data to fill the page */
rdata->iov[rdata->nr_iov].iov_base = kmap(page);
Expand Down Expand Up @@ -2996,18 +3003,20 @@ cifs_readpages_marshal_iov(struct cifs_readdata *rdata, unsigned int remaining)
* fill them until the writes are flushed.
*/
zero_user(page, 0, PAGE_CACHE_SIZE);
list_del(&page->lru);
lru_cache_add_file(page);
flush_dcache_page(page);
SetPageUptodate(page);
unlock_page(page);
page_cache_release(page);
rdata->pages[i] = NULL;
rdata->nr_pages--;
} else {
/* no need to hold page hostage */
list_del(&page->lru);
lru_cache_add_file(page);
unlock_page(page);
page_cache_release(page);
rdata->pages[i] = NULL;
rdata->nr_pages--;
}
}

Expand Down Expand Up @@ -3065,6 +3074,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
* the rdata->pages, then we want them in increasing order.
*/
while (!list_empty(page_list)) {
unsigned int i;
unsigned int bytes = PAGE_CACHE_SIZE;
unsigned int expected_index;
unsigned int nr_pages = 1;
Expand Down Expand Up @@ -3135,13 +3145,16 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
rdata->bytes = bytes;
rdata->pid = pid;
rdata->marshal_iov = cifs_readpages_marshal_iov;
list_splice_init(&tmplist, &rdata->pages);

list_for_each_entry_safe(page, tpage, &tmplist, lru) {
list_del(&page->lru);
rdata->pages[rdata->nr_pages++] = page;
}

rc = cifs_retry_async_readv(rdata);
if (rc != 0) {
list_for_each_entry_safe(page, tpage, &rdata->pages,
lru) {
list_del(&page->lru);
for (i = 0; i < rdata->nr_pages; i++) {
page = rdata->pages[i];
lru_cache_add_file(page);
unlock_page(page);
page_cache_release(page);
Expand Down

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