ceph: fix splice read for no Fc capability case
When iov_iter type is ITER_PIPE, copy_page_to_iter() increases
the page's reference and add the page to a pipe_buffer. It also
set the pipe_buffer's ops to page_cache_pipe_buf_ops. The comfirm
callback in page_cache_pipe_buf_ops expects the page is from page
cache and uptodate, otherwise it return error.
For ceph_sync_read() case, pages are not from page cache. So we
can't call copy_page_to_iter() when iov_iter type is ITER_PIPE.
The fix is using iov_iter_get_pages_alloc() to allocate pages
for the pipe. (the code is similar to default_file_splice_read)
Signed-off-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index ae3cec5..12ce2b5 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -458,71 +458,60 @@ enum {
* only return a short read to the caller if we hit EOF.
*/
static int striped_read(struct inode *inode,
- u64 off, u64 len,
+ u64 pos, u64 len,
struct page **pages, int num_pages,
- int *checkeof)
+ int page_align, int *checkeof)
{
struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
struct ceph_inode_info *ci = ceph_inode(inode);
- u64 pos, this_len, left;
+ u64 this_len;
loff_t i_size;
- int page_align, pages_left;
- int read, ret;
- struct page **page_pos;
+ int page_idx;
+ int ret, read = 0;
bool hit_stripe, was_short;
/*
* we may need to do multiple reads. not atomic, unfortunately.
*/
- pos = off;
- left = len;
- page_pos = pages;
- pages_left = num_pages;
- read = 0;
-
more:
- page_align = pos & ~PAGE_MASK;
- this_len = left;
+ this_len = len;
+ page_idx = (page_align + read) >> PAGE_SHIFT;
ret = ceph_osdc_readpages(&fsc->client->osdc, ceph_vino(inode),
&ci->i_layout, pos, &this_len,
- ci->i_truncate_seq,
- ci->i_truncate_size,
- page_pos, pages_left, page_align);
+ ci->i_truncate_seq, ci->i_truncate_size,
+ pages + page_idx, num_pages - page_idx,
+ ((page_align + read) & ~PAGE_MASK));
if (ret == -ENOENT)
ret = 0;
- hit_stripe = this_len < left;
+ hit_stripe = this_len < len;
was_short = ret >= 0 && ret < this_len;
- dout("striped_read %llu~%llu (read %u) got %d%s%s\n", pos, left, read,
+ dout("striped_read %llu~%llu (read %u) got %d%s%s\n", pos, len, read,
ret, hit_stripe ? " HITSTRIPE" : "", was_short ? " SHORT" : "");
i_size = i_size_read(inode);
if (ret >= 0) {
- int didpages;
if (was_short && (pos + ret < i_size)) {
int zlen = min(this_len - ret, i_size - pos - ret);
- int zoff = (off & ~PAGE_MASK) + read + ret;
+ int zoff = page_align + read + ret;
dout(" zero gap %llu to %llu\n",
- pos + ret, pos + ret + zlen);
+ pos + ret, pos + ret + zlen);
ceph_zero_page_vector_range(zoff, zlen, pages);
ret += zlen;
}
- didpages = (page_align + ret) >> PAGE_SHIFT;
+ read += ret;
pos += ret;
- read = pos - off;
- left -= ret;
- page_pos += didpages;
- pages_left -= didpages;
+ len -= ret;
/* hit stripe and need continue*/
- if (left && hit_stripe && pos < i_size)
+ if (len && hit_stripe && pos < i_size)
goto more;
}
if (read > 0) {
ret = read;
/* did we bounce off eof? */
- if (pos + left > i_size)
+ if (pos + len > i_size)
*checkeof = CHECK_EOF;
}
@@ -536,15 +525,16 @@ static int striped_read(struct inode *inode,
*
* If the read spans object boundary, just do multiple reads.
*/
-static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *i,
- int *checkeof)
+static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *to,
+ int *checkeof)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
struct page **pages;
u64 off = iocb->ki_pos;
- int num_pages, ret;
- size_t len = iov_iter_count(i);
+ int num_pages;
+ ssize_t ret;
+ size_t len = iov_iter_count(to);
dout("sync_read on file %p %llu~%u %s\n", file, off,
(unsigned)len,
@@ -563,35 +553,56 @@ static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *i,
if (ret < 0)
return ret;
- num_pages = calc_pages_for(off, len);
- pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
- if (IS_ERR(pages))
- return PTR_ERR(pages);
- ret = striped_read(inode, off, len, pages,
- num_pages, checkeof);
- if (ret > 0) {
- int l, k = 0;
- size_t left = ret;
+ if (unlikely(to->type & ITER_PIPE)) {
+ size_t page_off;
+ ret = iov_iter_get_pages_alloc(to, &pages, len,
+ &page_off);
+ if (ret <= 0)
+ return -ENOMEM;
+ num_pages = DIV_ROUND_UP(ret + page_off, PAGE_SIZE);
- while (left) {
- size_t page_off = off & ~PAGE_MASK;
- size_t copy = min_t(size_t, left,
- PAGE_SIZE - page_off);
- l = copy_page_to_iter(pages[k++], page_off, copy, i);
- off += l;
- left -= l;
- if (l < copy)
- break;
+ ret = striped_read(inode, off, ret, pages, num_pages,
+ page_off, checkeof);
+ if (ret > 0) {
+ iov_iter_advance(to, ret);
+ off += ret;
+ } else {
+ iov_iter_advance(to, 0);
}
+ ceph_put_page_vector(pages, num_pages, false);
+ } else {
+ num_pages = calc_pages_for(off, len);
+ pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
+ if (IS_ERR(pages))
+ return PTR_ERR(pages);
+
+ ret = striped_read(inode, off, len, pages, num_pages,
+ (off & ~PAGE_MASK), checkeof);
+ if (ret > 0) {
+ int l, k = 0;
+ size_t left = ret;
+
+ while (left) {
+ size_t page_off = off & ~PAGE_MASK;
+ size_t copy = min_t(size_t, left,
+ PAGE_SIZE - page_off);
+ l = copy_page_to_iter(pages[k++], page_off,
+ copy, to);
+ off += l;
+ left -= l;
+ if (l < copy)
+ break;
+ }
+ }
+ ceph_release_page_vector(pages, num_pages);
}
- ceph_release_page_vector(pages, num_pages);
if (off > iocb->ki_pos) {
ret = off - iocb->ki_pos;
iocb->ki_pos = off;
}
- dout("sync_read result %d\n", ret);
+ dout("sync_read result %zd\n", ret);
return ret;
}
@@ -1771,6 +1782,7 @@ const struct file_operations ceph_file_fops = {
.fsync = ceph_fsync,
.lock = ceph_lock,
.flock = ceph_flock,
+ .splice_read = generic_file_splice_read,
.splice_write = iter_file_splice_write,
.unlocked_ioctl = ceph_ioctl,
.compat_ioctl = ceph_ioctl,