For readv/preadv sync-operatoin, ceph only do the first iov.
It don't think other iovs.Now implement this.
V5:
-before getattr,it must put caps which already holded avoid deadlock.
-only do generic_segment_checks for sync-read avoid do again in func
generic_file_aio_read
V4:
-modify one bug.
V3:
-modify some bug.
V2:
-add generic_segment_checks
-using struct iov_iter replace cloning the iovs.
-return previous successfully copied if ceph_copy_page_vector_to_user
met error.
Signed-off-by: Jianpeng Ma <majianpeng@xxxxxxxxx>
---
fs/ceph/file.c | 149 +++++++++++++++++++++++++++++++++++++++++----------------
1 file changed, 107 insertions(+), 42 deletions(-)
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 3de8982..5422d8e 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -408,51 +408,94 @@ more:
*
* If the read spans object boundary, just do multiple reads.
*/
-static ssize_t ceph_sync_read(struct file *file, char __user *data,
- unsigned len, loff_t *poff, int *checkeof)
+static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *i,
+ int *checkeof)
{
+ struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
struct page **pages;
- u64 off = *poff;
+ u64 off = iocb->ki_pos;
int num_pages, ret;
- dout("sync_read on file %p %llu~%u %s\n", file, off, len,
+ dout("sync_read on file %p %llu~%u %s\n", file, off,
+ (unsigned)iocb->ki_left,
(file->f_flags & O_DIRECT) ? "O_DIRECT" : "");
-
- if (file->f_flags & O_DIRECT) {
- num_pages = calc_pages_for((unsigned long)data, len);
- pages = ceph_get_direct_page_vector(data, num_pages, true);
- } else {
- num_pages = calc_pages_for(off, len);
- pages = ceph_alloc_page_vector(num_pages, GFP_NOFS);
- }
- if (IS_ERR(pages))
- return PTR_ERR(pages);
-
/*
* flush any page cache pages in this range. this
* will make concurrent normal and sync io slow,
* but it will at least behave sensibly when they are
* in sequence.
*/
- ret = filemap_write_and_wait(inode->i_mapping);
+ ret = filemap_write_and_wait_range(inode->i_mapping, off,
+ off + iocb->ki_left);
if (ret < 0)
- goto done;
-
- ret = striped_read(inode, off, len, pages, num_pages, checkeof,
- file->f_flags & O_DIRECT,
- (unsigned long)data & ~PAGE_MASK);
+ return ret;
- if (ret >= 0 && (file->f_flags & O_DIRECT) == 0)
- ret = ceph_copy_page_vector_to_user(pages, data, off, ret);
- if (ret >= 0)
- *poff = off + ret;
+ if (file->f_flags & O_DIRECT) {
+ while (iov_iter_count(i)) {
+ void __user *data = i->iov[0].iov_base + i->iov_offset;
+ size_t len = i->iov[0].iov_len - i->iov_offset;
+
+ num_pages = calc_pages_for((unsigned long)data, len);
+ pages = ceph_get_direct_page_vector(data,
+ num_pages, true);
+ if (IS_ERR(pages))
+ return PTR_ERR(pages);
+
+ ret = striped_read(inode, off, len,
+ pages, num_pages, checkeof,
+ 1, (unsigned long)data & ~PAGE_MASK);
+ ceph_put_page_vector(pages, num_pages, true);
+
+ if (ret <= 0)
+ break;
+ off += ret;
+ iov_iter_advance(i, ret);
+ if (ret < len)
+ break;
+ }
+ } else {
+ size_t len = iocb->ki_left;
-done:
- if (file->f_flags & O_DIRECT)
- ceph_put_page_vector(pages, num_pages, true);
- else
+ num_pages = calc_pages_for(off, len);
+ pages = ceph_alloc_page_vector(num_pages, GFP_NOFS);
+ if (IS_ERR(pages))
+ return PTR_ERR(pages);
+ ret = striped_read(inode, off, len, pages,
+ num_pages, checkeof, 0, 0);
+ if (ret > 0) {
+ int l, k = 0;
+ size_t left = len = ret;
+
+ while (left) {
+ void __user *data = i->iov[0].iov_base
+ + i->iov_offset;
+ l = min(i->iov[0].iov_len - i->iov_offset,
+ left);
+
+ ret = ceph_copy_page_vector_to_user(&pages[k],
+ data, off,
+ l);
+ if (ret > 0) {
+ iov_iter_advance(i, ret);
+ left -= ret;
+ off += ret;
+ k = calc_pages_for(iocb->ki_pos,
+ len - left + 1) - 1;
+ BUG_ON(k >= num_pages && left);
+ } else
+ break;
+ }
+ }
ceph_release_page_vector(pages, num_pages);
+ }
+
+ if (off > iocb->ki_pos) {
+ ret = off - iocb->ki_pos;
+ iocb->ki_pos = off;
+ iocb->ki_left -= ret;
+ }
+
dout("sync_read result %d\n", ret);
return ret;
}
@@ -647,17 +690,16 @@ static ssize_t ceph_aio_read(struct kiocb *iocb, const struct iovec *iov,
{
struct file *filp = iocb->ki_filp;
struct ceph_file_info *fi = filp->private_data;
- loff_t *ppos = &iocb->ki_pos;
- size_t len = iov->iov_len;
+ size_t len = 0;
struct inode *inode = file_inode(filp);
struct ceph_inode_info *ci = ceph_inode(inode);
- void __user *base = iov->iov_base;
ssize_t ret;
int want, got = 0;
int checkeof = 0, read = 0;
dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
inode, ceph_vinop(inode), pos, (unsigned)len, inode);
+
again:
if (fi->fmode & CEPH_FILE_MODE_LAZY)
want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
@@ -665,38 +707,61 @@ again:
want = CEPH_CAP_FILE_CACHE;
ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, want, &got, -1);
if (ret < 0)
- goto out;
+ return ret;
+
dout("aio_read %p %llx.%llx %llu~%u got cap refs on %s\n",
inode, ceph_vinop(inode), pos, (unsigned)len,
ceph_cap_string(got));
if ((got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0 ||
(iocb->ki_filp->f_flags & O_DIRECT) ||
- (fi->flags & CEPH_F_SYNC))
+ (fi->flags & CEPH_F_SYNC)) {
+ struct iov_iter i;
+
+ if (!read) {
+ ret = generic_segment_checks(iov, &nr_segs,
+ &len, VERIFY_WRITE);
+ if (ret)
+ goto out;
+ }
+
+ iocb->ki_left = len;
+ iov_iter_init(&i, iov, nr_segs, len, read);
/* hmm, this isn't really async... */
- ret = ceph_sync_read(filp, base, len, ppos, &checkeof);
- else
+ ret = ceph_sync_read(iocb, &i, &checkeof);
+ } else {
+ /*
+ * We can't modify the content of iov,
+ * so we only read from beginning.
+ */
+ if (read)
+ iocb->ki_pos = pos;
ret = generic_file_aio_read(iocb, iov, nr_segs, pos);
-
+ }
out:
dout("aio_read %p %llx.%llx dropping cap refs on %s = %d\n",
inode, ceph_vinop(inode), ceph_cap_string(got), (int)ret);
ceph_put_cap_refs(ci, got);
if (checkeof && ret >= 0) {
- int statret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE);
+ int statret = ceph_do_getattr(inode,
+ CEPH_STAT_CAP_SIZE);
/* hit EOF or hole? */
- if (statret == 0 && *ppos < inode->i_size) {
- dout("aio_read sync_read hit hole, ppos %lld < size %lld, reading more\n", *ppos, inode->i_size);
+ if (statret == 0 && iocb->ki_pos < inode->i_size &&
+ iocb->ki_left) {
+ dout("sync_read hit hole, ppos %lld < size %lld"
+ ", reading more\n", iocb->ki_pos,
+ inode->i_size);
+
read += ret;
- base += ret;
len -= ret;
checkeof = 0;
goto again;
}
}
- if (ret >= 0)
+
+ if (ret > 0)
ret += read;
return ret;
--
1.8.4-rc0
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