On 09/05/2013 08:28 AM, majianpeng wrote:
>> On 09/03/2013 04:52 PM, majianpeng wrote:
>>> For readv/preadv sync-operatoin, ceph only do the first iov.
>>> It don't think other iovs.Now implement this.
>>>
>>> Signed-off-by: Jianpeng Ma <majianpeng@xxxxxxxxx>
>>> ---
>>> fs/ceph/file.c | 175 ++++++++++++++++++++++++++++++++++++++++-----------------
>>> 1 file changed, 123 insertions(+), 52 deletions(-)
>>>
>>> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
>>> index 3de8982..7d6a3ee 100644
>>> --- a/fs/ceph/file.c
>>> +++ b/fs/ceph/file.c
>>> @@ -408,51 +408,95 @@ 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 iovec *iov,
>>> + unsigned long nr_segs, int *checkeof)
>>> {
>>> + struct file *file = iocb->ki_filp;
>>> struct inode *inode = file_inode(file);
>>> struct page **pages;
>>> - u64 off = *poff;
>>> - int num_pages, ret;
>>> + u64 off = iocb->ki_pos;
>>> + int num_pages, ret, i;
>>>
>>> - 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) {
>>> + for (i = 0; i < nr_segs; i++) {
>>> + void __user *data = iov[i].iov_base;
>>> + size_t len = iov[i].iov_len;
>>> +
>>> + 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;
>>> + if (ret < len)
>>> + break;
>>> + }
>>> + if (off > iocb->ki_pos) {
>>> + ret = off - iocb->ki_pos;
>>> + iocb->ki_pos = off;
>>> + iocb->ki_left -= ret;
>>> + }
>>> + } 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);
>>> + len = ret;
>>> + if (len) {
>>> + int i, l, k = 0;
>>> + size_t left = len;
>>> +
>>> + for (i = 0; i < nr_segs && left; i++) {
>>> + void __user *data = iov[i].iov_base;
>>> + l = min(left, iov[i].iov_len);
>>> + ret = ceph_copy_page_vector_to_user(&pages[k],
>>> + data, off,
>>> + l);
>>> + if (ret > 0) {
>>> + left -= ret;
>>> + off += ret;
>>> + k = calc_pages_for(iocb->ki_pos,
>>> + len - left + 1) - 1;
>>> + BUG_ON(k >= num_pages && left);
>>> + } else
>>> + break;
>>> + }
>>> +
>>> + if (left == 0) {
>>> + iocb->ki_pos += len;
>>> + iocb->ki_left -= len;
>>> + ret = len;
>>> + }
>>
>> If user program provides invalid buffer to readv syscall. 'left' can be larger than 0.
>> For this case, we should return size of data that were successfully copied
> Ok, we should add this code, before "if (left == 0)"
> left = len - left;
>
>>
>>> + }
>>> ceph_release_page_vector(pages, num_pages);
>>> + }
>>> +
>>> dout("sync_read result %d\n", ret);
>>> return ret;
>>> }
>>> @@ -647,55 +691,82 @@ 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 = iocb->ki_left;
>>> 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;
>>> else
>>> 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)) {
>>> + unsigned long curr_seg = 0;
>>> + struct iovec *iov_clone;
>>> +
>>> + iov_clone = kmalloc(nr_segs * sizeof(struct iovec), GFP_KERNEL);
>>> + if (iov_clone == NULL) {
>>> + ret = -ENOMEM;
>>> + goto out;
>>> + }
>>> + memcpy(iov_clone, iov, nr_segs * sizeof(struct iovec));
>>
>> why do we need to clone the iov ?
>>
> I noticed in patch2,you asked the same question.
> The reason is i need modify iov,but the iov is const.So i only clone it.
> Or should you have better method?
>
use iov iterator. see generic_file_buffered_write()
Regards
Yan, Zheng
>> Regards
>> Yan, Zheng
>>
>>> +again:
>>> /* hmm, this isn't really async... */
>>> - ret = ceph_sync_read(filp, base, len, ppos, &checkeof);
>>> - else
>>> - ret = generic_file_aio_read(iocb, iov, nr_segs, pos);
>>> + ret = ceph_sync_read(iocb, &iov_clone[curr_seg],
>>> + nr_segs - curr_seg, &checkeof);
>>> +
>>> + if (checkeof && ret >= 0) {
>>> + int statret = ceph_do_getattr(inode,
>>> + CEPH_STAT_CAP_SIZE);
>>> +
>>> + /* hit EOF or hole? */
>>> + if (statret == 0 && iocb->ki_pos < inode->i_size &&
>>> + iocb->ki_left) {
>>> + size_t tmp = 0;
>>> + dout("%s sync_read hit hole, ppos %lld < size %lld"
>>> + ", reading more\n", __func__, iocb->ki_pos,
>>> + inode->i_size);
>>> +
>>> + read += ret;
>>> + for (; curr_seg < nr_segs; curr_seg++) {
>>> + if ((tmp + iov_clone[curr_seg].iov_len)
>>> + > ret)
>>> + break;
>>> + tmp += iov_clone[curr_seg].iov_len;
>>> + }
>>> +
>>> + BUG_ON(curr_seg == nr_segs);
>>> + iov_clone[curr_seg].iov_base += ret - tmp;
>>> + iov_clone[curr_seg].iov_len -= ret - tmp;
>>> + checkeof = 0;
>>> + goto again;
>>> + }
>>> + }
>>> + kfree(iov_clone);
>>>
>>> + } else
>>> + 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);
>>> -
>>> - /* 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);
>>> - read += ret;
>>> - base += ret;
>>> - len -= ret;
>>> - checkeof = 0;
>>> - goto again;
>>> - }
>>> - }
>>> if (ret >= 0)
>>> ret += read;
>>>
>>>
>>
>
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