diff mbox

[V2,1/2] ceph: Implement readv/preadv for sync operation.

Message ID 201309061648229668212@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

majianpeng Sept. 6, 2013, 8:48 a.m. UTC 
For readv/preadv sync-operatoin, ceph only do the first iov.
It don't think other iovs.Now implement this.

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@gmail.com>

---
 fs/ceph/file.c | 174 ++++++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 123 insertions(+), 51 deletions(-)

-- 
1.8.1.2

Comments

Yan, Zheng Sept. 7, 2013, 12:50 a.m. UTC | #1 
On 09/06/2013 04:48 PM, majianpeng wrote:
> For readv/preadv sync-operatoin, ceph only do the first iov.
> It don't think other iovs.Now implement this.
> 
> 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@gmail.com>
> ---
>  fs/ceph/file.c | 174 ++++++++++++++++++++++++++++++++++++++++-----------------
>  1 file changed, 123 insertions(+), 51 deletions(-)
> 
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index 3de8982..1c28c52 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -408,51 +408,109 @@ 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;
> -	int num_pages, ret;
> +	u64 off = iocb->ki_pos;
> +	int num_pages, ret, n;
>  
> -	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;
> +		return ret;
>  
> -	ret = striped_read(inode, off, len, pages, num_pages, checkeof,
> -			   file->f_flags & O_DIRECT,
> -			   (unsigned long)data & ~PAGE_MASK);
> +	if (file->f_flags & O_DIRECT) {
> +		for (n = 0; n < i->nr_segs; n++) {
> +			void __user *data = i->iov[n].iov_base;
> +			size_t len = i->iov[n].iov_len;
> +
> +			if (n == 0) {
> +				len -=  i->iov_offset;
> +				data += 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;
> +			if (ret < len)
> +				break;
> +		}
>  
> -	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 (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 l, k = 0;
> +			size_t left = len;
> +
> +			for (n = 0; n < i->nr_segs && left; n++) {
> +				void __user *data = i->iov[n].iov_base;
> +				l = min(left, i->iov[n].iov_len);
> +
> +				if (n == 0) {
> +					data += 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) {
> +					left -= ret;
> +					off += ret;
> +					k = calc_pages_for(iocb->ki_pos,
> +							   len - left + 1) - 1;
> +					BUG_ON(k >= num_pages && left);
> +				} else
> +					break;
> +			}

I think it's better to call iov_iter_advance() here instead of in ceph_aio_read(),
and change the code to something like:
----
while (iov_iter_count(&i) && left > 0) {
   void __user *data = i->iov->iov_base + i->iov_offset;
   l = min(left, i->iov->iov_len - i->iov_offset);

   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;
}


rest change looks good.

Regards
Yan, Zheng

> +
> +			len -= left;
> +			if (len > 0) {
> +				iocb->ki_pos += len;
> +				iocb->ki_left -= len;
> +				ret = len;
> +			}
> +		}
>  		ceph_release_page_vector(pages, num_pages);
> +	}
> +
>  	dout("sync_read result %d\n", ret);
>  	return ret;
>  }
> @@ -647,55 +705,69 @@ 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:
> +
> +	ret = generic_segment_checks(iov, &nr_segs, &len, VERIFY_WRITE);
> +	if (ret)
> +		return ret;
> +
>  	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)) {
> +		struct iov_iter i;
> +
> +		iocb->ki_left = len;
> +		iov_iter_init(&i, iov, nr_segs, len, 0);
> +again:
>  		/* hmm, this isn't really async... */
> -		ret = ceph_sync_read(filp, base, len, ppos, &checkeof);
> -	else
> +		ret = ceph_sync_read(iocb, &i, &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) {
> +				dout("sync_read hit hole, ppos %lld < size %lld"
> +				     ", reading more\n", iocb->ki_pos,
> +				     inode->i_size);
> +
> +				read += ret;
> +				iov_iter_advance(&i, ret);
> +				checkeof = 0;
> +				goto again;
> +			}
> +		}
> +
> +	} 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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diff mbox

Patch

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 3de8982..1c28c52 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -408,51 +408,109 @@  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;
-	int num_pages, ret;
+	u64 off = iocb->ki_pos;
+	int num_pages, ret, n;
 
-	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;
+		return ret;
 
-	ret = striped_read(inode, off, len, pages, num_pages, checkeof,
-			   file->f_flags & O_DIRECT,
-			   (unsigned long)data & ~PAGE_MASK);
+	if (file->f_flags & O_DIRECT) {
+		for (n = 0; n < i->nr_segs; n++) {
+			void __user *data = i->iov[n].iov_base;
+			size_t len = i->iov[n].iov_len;
+
+			if (n == 0) {
+				len -=  i->iov_offset;
+				data += 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;
+			if (ret < len)
+				break;
+		}
 
-	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 (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 l, k = 0;
+			size_t left = len;
+
+			for (n = 0; n < i->nr_segs && left; n++) {
+				void __user *data = i->iov[n].iov_base;
+				l = min(left, i->iov[n].iov_len);
+
+				if (n == 0) {
+					data += 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) {
+					left -= ret;
+					off += ret;
+					k = calc_pages_for(iocb->ki_pos,
+							   len - left + 1) - 1;
+					BUG_ON(k >= num_pages && left);
+				} else
+					break;
+			}
+
+			len -= left;
+			if (len > 0) {
+				iocb->ki_pos += len;
+				iocb->ki_left -= len;
+				ret = len;
+			}
+		}
 		ceph_release_page_vector(pages, num_pages);
+	}
+
 	dout("sync_read result %d\n", ret);
 	return ret;
 }
@@ -647,55 +705,69 @@  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:
+
+	ret = generic_segment_checks(iov, &nr_segs, &len, VERIFY_WRITE);
+	if (ret)
+		return ret;
+
 	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)) {
+		struct iov_iter i;
+
+		iocb->ki_left = len;
+		iov_iter_init(&i, iov, nr_segs, len, 0);
+again:
 		/* hmm, this isn't really async... */
-		ret = ceph_sync_read(filp, base, len, ppos, &checkeof);
-	else
+		ret = ceph_sync_read(iocb, &i, &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) {
+				dout("sync_read hit hole, ppos %lld < size %lld"
+				     ", reading more\n", iocb->ki_pos,
+				     inode->i_size);
+
+				read += ret;
+				iov_iter_advance(&i, ret);
+				checkeof = 0;
+				goto again;
+			}
+		}
+
+	} 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;