[RESEND PATCH V7] ceph:Implement readv/preadv for sync operation

[RESEND PATCH V7] ceph:Implement readv/preadv for sync operation

[majianpeng]

For readv/preadv sync-operatoin, ceph only do the first iov.
It don't think other iovs.Now implement this.

V7:
   Because commit 73a7075e3f6ec63dc remove the ki_left of struct iocb.
   So rewrite this patch. Test on v3.12-rc2, it looks good.
V6:
   Fix some bugs;
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 bugs.
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 | 162 +++++++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 116 insertions(+), 46 deletions(-)

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 3de8982..c945621 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -408,51 +408,92 @@ 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;
+	size_t len = i->count;
 
-	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)len,
 	     (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 + len);
 	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) {
+		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 {
+		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 (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;
+	}
 
-done:
-	if (file->f_flags & O_DIRECT)
-		ceph_put_page_vector(pages, num_pages, true);
-	else
-		ceph_release_page_vector(pages, num_pages);
 	dout("sync_read result %d\n", ret);
 	return ret;
 }
@@ -647,55 +688,84 @@ 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_nbytes;
 	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;
 
+again:
 	dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
-	     inode, ceph_vinop(inode), pos, (unsigned)len, inode);
-again:
+	     inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len, inode);
+
 	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;
-	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));
+		return ret;
 
 	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;
+
+		dout("aio_sync_read %p %llx.%llx %llu~%u got cap refs on %s\n",
+		     inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len,
+		     ceph_cap_string(got));
+
+		if (!read) {
+			ret = generic_segment_checks(iov, &nr_segs,
+							&len, VERIFY_WRITE);
+			if (ret)
+				goto out;
+		}
+
+		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 = generic_file_aio_read(iocb, iov, nr_segs, pos);
+		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;
+			len = iocb->ki_nbytes;
+			read = 0;
+		}
+		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));
 
+		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 &&
+			ret < len) {
+			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)
 		ret += read;
 
-- 
1.8.4-rc0

Re: [RESEND PATCH V7] ceph:Implement readv/preadv for sync operation

[Yan, Zheng]

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>

On 09/26/2013 02:42 PM, majianpeng wrote:
> For readv/preadv sync-operatoin, ceph only do the first iov.
> It don't think other iovs.Now implement this.
> 
> V7:
>    Because commit 73a7075e3f6ec63dc remove the ki_left of struct iocb.
>    So rewrite this patch. Test on v3.12-rc2, it looks good.
> V6:
>    Fix some bugs;
> 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 bugs.
> 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 | 162 +++++++++++++++++++++++++++++++++++++++++----------------
>  1 file changed, 116 insertions(+), 46 deletions(-)
> 
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index 3de8982..c945621 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -408,51 +408,92 @@ 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;
> +	size_t len = i->count;
>  
> -	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)len,
>  	     (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 + len);
>  	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) {
> +		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 {
> +		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 (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;
> +	}
>  
> -done:
> -	if (file->f_flags & O_DIRECT)
> -		ceph_put_page_vector(pages, num_pages, true);
> -	else
> -		ceph_release_page_vector(pages, num_pages);
>  	dout("sync_read result %d\n", ret);
>  	return ret;
>  }
> @@ -647,55 +688,84 @@ 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_nbytes;
>  	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;
>  
> +again:
>  	dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
> -	     inode, ceph_vinop(inode), pos, (unsigned)len, inode);
> -again:
> +	     inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len, inode);
> +
>  	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;
> -	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));
> +		return ret;
>  
>  	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;
> +
> +		dout("aio_sync_read %p %llx.%llx %llu~%u got cap refs on %s\n",
> +		     inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len,
> +		     ceph_cap_string(got));
> +
> +		if (!read) {
> +			ret = generic_segment_checks(iov, &nr_segs,
> +							&len, VERIFY_WRITE);
> +			if (ret)
> +				goto out;
> +		}
> +
> +		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 = generic_file_aio_read(iocb, iov, nr_segs, pos);
> +		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;
> +			len = iocb->ki_nbytes;
> +			read = 0;
> +		}
> +		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));
>  
> +		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 &&
> +			ret < len) {
> +			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)
>  		ret += read;
>  
> 

Re: Re: [RESEND PATCH V7] ceph:Implement readv/preadv for sync operation

[majianpeng]

>Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
>
Thanks very much!
Jianpeng Ma
>On 09/26/2013 02:42 PM, majianpeng wrote:
>> For readv/preadv sync-operatoin, ceph only do the first iov.
>> It don't think other iovs.Now implement this.
>> 
>> V7:
>>    Because commit 73a7075e3f6ec63dc remove the ki_left of struct iocb.
>>    So rewrite this patch. Test on v3.12-rc2, it looks good.
>> V6:
>>    Fix some bugs;
>> 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 bugs.
>> 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 | 162 +++++++++++++++++++++++++++++++++++++++++----------------
>>  1 file changed, 116 insertions(+), 46 deletions(-)
>> 
>> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
>> index 3de8982..c945621 100644
>> --- a/fs/ceph/file.c
>> +++ b/fs/ceph/file.c
>> @@ -408,51 +408,92 @@ 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;
>> +	size_t len = i->count;
>>  
>> -	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)len,
>>  	     (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 + len);
>>  	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) {
>> +		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 {
>> +		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 (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;
>> +	}
>>  
>> -done:
>> -	if (file->f_flags & O_DIRECT)
>> -		ceph_put_page_vector(pages, num_pages, true);
>> -	else
>> -		ceph_release_page_vector(pages, num_pages);
>>  	dout("sync_read result %d\n", ret);
>>  	return ret;
>>  }
>> @@ -647,55 +688,84 @@ 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_nbytes;
>>  	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;
>>  
>> +again:
>>  	dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
>> -	     inode, ceph_vinop(inode), pos, (unsigned)len, inode);
>> -again:
>> +	     inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len, inode);
>> +
>>  	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;
>> -	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));
>> +		return ret;
>>  
>>  	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;
>> +
>> +		dout("aio_sync_read %p %llx.%llx %llu~%u got cap refs on %s\n",
>> +		     inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len,
>> +		     ceph_cap_string(got));
>> +
>> +		if (!read) {
>> +			ret = generic_segment_checks(iov, &nr_segs,
>> +							&len, VERIFY_WRITE);
>> +			if (ret)
>> +				goto out;
>> +		}
>> +
>> +		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 = generic_file_aio_read(iocb, iov, nr_segs, pos);
>> +		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;
>> +			len = iocb->ki_nbytes;
>> +			read = 0;
>> +		}
>> +		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));
>>  
>> +		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 &&
>> +			ret < len) {
>> +			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)
>>  		ret += read;
>>  
>> 
>

Re: [RESEND PATCH V7] ceph:Implement readv/preadv for sync operation

[Sage Weil]

Applied to the testing branch.  I'll move it master after it goes 
through the nightly tests a few times.

Thanks!
sage


On Thu, 26 Sep 2013, majianpeng wrote:

> For readv/preadv sync-operatoin, ceph only do the first iov.
> It don't think other iovs.Now implement this.
> 
> V7:
>    Because commit 73a7075e3f6ec63dc remove the ki_left of struct iocb.
>    So rewrite this patch. Test on v3.12-rc2, it looks good.
> V6:
>    Fix some bugs;
> 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 bugs.
> 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 | 162 +++++++++++++++++++++++++++++++++++++++++----------------
>  1 file changed, 116 insertions(+), 46 deletions(-)
> 
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index 3de8982..c945621 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -408,51 +408,92 @@ 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;
> +	size_t len = i->count;
>  
> -	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)len,
>  	     (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 + len);
>  	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) {
> +		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 {
> +		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 (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;
> +	}
>  
> -done:
> -	if (file->f_flags & O_DIRECT)
> -		ceph_put_page_vector(pages, num_pages, true);
> -	else
> -		ceph_release_page_vector(pages, num_pages);
>  	dout("sync_read result %d\n", ret);
>  	return ret;
>  }
> @@ -647,55 +688,84 @@ 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_nbytes;
>  	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;
>  
> +again:
>  	dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
> -	     inode, ceph_vinop(inode), pos, (unsigned)len, inode);
> -again:
> +	     inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len, inode);
> +
>  	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;
> -	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));
> +		return ret;
>  
>  	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;
> +
> +		dout("aio_sync_read %p %llx.%llx %llu~%u got cap refs on %s\n",
> +		     inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len,
> +		     ceph_cap_string(got));
> +
> +		if (!read) {
> +			ret = generic_segment_checks(iov, &nr_segs,
> +							&len, VERIFY_WRITE);
> +			if (ret)
> +				goto out;
> +		}
> +
> +		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 = generic_file_aio_read(iocb, iov, nr_segs, pos);
> +		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;
> +			len = iocb->ki_nbytes;
> +			read = 0;
> +		}
> +		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));
>  
> +		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 &&
> +			ret < len) {
> +			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)
>  		ret += read;
>  
> -- 
> 1.8.4-rc0
>