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Commit 65ed39d6 authored by Mark Fasheh's avatar Mark Fasheh
Browse files

ocfs2: move nonsparse hole-filling into ocfs2_write_begin() 



By doing this, we can remove any higher level logic which has to have
knowledge of btree functionality - any callers of ocfs2_write_begin() can
now expect it to do anything necessary to prepare the inode for new data.

Signed-off-by: default avatarMark Fasheh <mark.fasheh@oracle.com>
Reviewed-by: default avatarJoel Becker <joel.becker@oracle.com>
parent 92e91ce2

fs/ocfs2/aops.c

+36 −4
Original line number Diff line number Diff line
@@ -301,12 +301,8 @@ int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page, 
{

	int ret;



	down_read(&OCFS2_I(inode)->ip_alloc_sem);



	ret = block_prepare_write(page, from, to, ocfs2_get_block);



	up_read(&OCFS2_I(inode)->ip_alloc_sem);



	return ret;

}
@@ -1360,6 +1356,36 @@ static int ocfs2_populate_write_desc(struct inode *inode, 
	return ret;

}



/*

 * This function only does anything for file systems which can't

 * handle sparse files.

 *

 * What we want to do here is fill in any hole between the current end

 * of allocation and the end of our write. That way the rest of the

 * write path can treat it as an non-allocating write, which has no

 * special case code for sparse/nonsparse files.

 */

static int ocfs2_expand_nonsparse_inode(struct inode *inode, loff_t pos,

					unsigned len,

					struct ocfs2_write_ctxt *wc)

{

	int ret;

	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	loff_t newsize = pos + len;



	if (ocfs2_sparse_alloc(osb))

		return 0;



	if (newsize <= i_size_read(inode))

		return 0;



	ret = ocfs2_extend_no_holes(inode, newsize, newsize - len);

	if (ret)

		mlog_errno(ret);



	return ret;

}



int ocfs2_write_begin_nolock(struct address_space *mapping,

			     loff_t pos, unsigned len, unsigned flags,

			     struct page **pagep, void **fsdata,
@@ -1381,6 +1407,12 @@ int ocfs2_write_begin_nolock(struct address_space *mapping, 
		return ret;

	}



	ret = ocfs2_expand_nonsparse_inode(inode, pos, len, wc);

	if (ret) {

		mlog_errno(ret);

		goto out;

	}



	ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,

					&extents_to_split);

	if (ret) {

fs/ocfs2/file.c

+77 −140
Original line number Diff line number Diff line
@@ -779,25 +779,6 @@ static int __ocfs2_extend_allocation(struct inode *inode, u32 logical_start, 
	return status;

}



static int ocfs2_extend_allocation(struct inode *inode, u32 logical_start,

				   u32 clusters_to_add, int mark_unwritten)

{

	int ret;



	/*

	 * The alloc sem blocks peope in read/write from reading our

	 * allocation until we're done changing it. We depend on

	 * i_mutex to block other extend/truncate calls while we're

	 * here.

	 */

	down_write(&OCFS2_I(inode)->ip_alloc_sem);

	ret = __ocfs2_extend_allocation(inode, logical_start, clusters_to_add,

					mark_unwritten);

	up_write(&OCFS2_I(inode)->ip_alloc_sem);



	return ret;

}



/* Some parts of this taken from generic_cont_expand, which turned out

 * to be too fragile to do exactly what we need without us having to

 * worry about recursive locking in ->prepare_write() and
@@ -889,25 +870,47 @@ static int ocfs2_zero_extend(struct inode *inode, 
	return ret;

}



int ocfs2_extend_no_holes(struct inode *inode, u64 new_i_size, u64 zero_to)

{

	int ret;

	u32 clusters_to_add;

	struct ocfs2_inode_info *oi = OCFS2_I(inode);



	clusters_to_add = ocfs2_clusters_for_bytes(inode->i_sb, new_i_size);

	if (clusters_to_add < oi->ip_clusters)

		clusters_to_add = 0;

	else

		clusters_to_add -= oi->ip_clusters;



	if (clusters_to_add) {

		ret = __ocfs2_extend_allocation(inode, oi->ip_clusters,

						clusters_to_add, 0);

		if (ret) {

			mlog_errno(ret);

			goto out;

		}

	}



	/*

 * A tail_to_skip value > 0 indicates that we're being called from

 * ocfs2_file_aio_write(). This has the following implications:

 *

 * - we don't want to update i_size

 * - di_bh will be NULL, which is fine because it's only used in the

 *   case where we want to update i_size.

 * - ocfs2_zero_extend() will then only be filling the hole created

 *   between i_size and the start of the write.

	 * Call this even if we don't add any clusters to the tree. We

	 * still need to zero the area between the old i_size and the

	 * new i_size.

	 */

	ret = ocfs2_zero_extend(inode, zero_to);

	if (ret < 0)

		mlog_errno(ret);



out:

	return ret;

}



static int ocfs2_extend_file(struct inode *inode,

			     struct buffer_head *di_bh,

			     u64 new_i_size,

			     size_t tail_to_skip)

			     u64 new_i_size)

{

	int ret = 0;

	u32 clusters_to_add = 0;



	BUG_ON(!tail_to_skip && !di_bh);

	BUG_ON(!di_bh);



	/* setattr sometimes calls us like this. */

	if (new_i_size == 0)
@@ -917,13 +920,8 @@ static int ocfs2_extend_file(struct inode *inode, 
  		goto out;

	BUG_ON(new_i_size < i_size_read(inode));



	if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) {

		BUG_ON(tail_to_skip != 0);

	if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))

		goto out_update_size;

	}



	clusters_to_add = ocfs2_clusters_for_bytes(inode->i_sb, new_i_size) - 

		OCFS2_I(inode)->ip_clusters;



	/* 

	 * protect the pages that ocfs2_zero_extend is going to be
@@ -938,35 +936,25 @@ static int ocfs2_extend_file(struct inode *inode, 
		goto out;

	}



	if (clusters_to_add) {

		ret = ocfs2_extend_allocation(inode,

					      OCFS2_I(inode)->ip_clusters,

					      clusters_to_add, 0);

		if (ret < 0) {

			mlog_errno(ret);

			goto out_unlock;

		}

	}



	/*

	 * Call this even if we don't add any clusters to the tree. We

	 * still need to zero the area between the old i_size and the

	 * new i_size.

	 * The alloc sem blocks people in read/write from reading our

	 * allocation until we're done changing it. We depend on

	 * i_mutex to block other extend/truncate calls while we're

	 * here.

	 */

	ret = ocfs2_zero_extend(inode, (u64)new_i_size - tail_to_skip);

	down_write(&OCFS2_I(inode)->ip_alloc_sem);

	ret = ocfs2_extend_no_holes(inode, new_i_size, new_i_size);

	up_write(&OCFS2_I(inode)->ip_alloc_sem);



	if (ret < 0) {

		mlog_errno(ret);

		goto out_unlock;

	}



out_update_size:

	if (!tail_to_skip) {

		/* We're being called from ocfs2_setattr() which wants

		 * us to update i_size */

	ret = ocfs2_simple_size_update(inode, di_bh, new_i_size);

	if (ret < 0)

		mlog_errno(ret);

	}



out_unlock:

	if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
@@ -1035,7 +1023,7 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr *attr) 
		if (i_size_read(inode) > attr->ia_size)

			status = ocfs2_truncate_file(inode, bh, attr->ia_size);

		else

			status = ocfs2_extend_file(inode, bh, attr->ia_size, 0);

			status = ocfs2_extend_file(inode, bh, attr->ia_size);

		if (status < 0) {

			if (status != -ENOSPC)

				mlog_errno(status);
@@ -1713,15 +1701,13 @@ static int ocfs2_prepare_inode_for_write(struct dentry *dentry, 
					 int appending,

					 int *direct_io)

{

	int ret = 0, meta_level = appending;

	int ret = 0, meta_level = 0;

	struct inode *inode = dentry->d_inode;

	u32 clusters;

	loff_t newsize, saved_pos;

	loff_t saved_pos, end;



	/* 

	 * We sample i_size under a read level meta lock to see if our write

	 * is extending the file, if it is we back off and get a write level

	 * meta lock.

	 * We start with a read level meta lock and only jump to an ex

	 * if we need to make modifications here.

	 */

	for(;;) {

		ret = ocfs2_meta_lock(inode, NULL, meta_level);
@@ -1763,8 +1749,7 @@ static int ocfs2_prepare_inode_for_write(struct dentry *dentry, 
			saved_pos = *ppos;

		}



		if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) {

			loff_t end = saved_pos + count;

		end = saved_pos + count;



		/*

		 * Skip the O_DIRECT checks if we don't need
@@ -1790,8 +1775,7 @@ static int ocfs2_prepare_inode_for_write(struct dentry *dentry, 
		 * caller will have to retake some cluster

		 * locks and initiate the io as buffered.

		 */

			ret = ocfs2_check_range_for_holes(inode, saved_pos,

							  count);

		ret = ocfs2_check_range_for_holes(inode, saved_pos, count);

		if (ret == 1) {

			*direct_io = 0;

			ret = 0;
@@ -1800,53 +1784,6 @@ static int ocfs2_prepare_inode_for_write(struct dentry *dentry, 
		break;

	}



		/*

		 * The rest of this loop is concerned with legacy file

		 * systems which don't support sparse files.

		 */



		newsize = count + saved_pos;



		mlog(0, "pos=%lld newsize=%lld cursize=%lld\n",

		     (long long) saved_pos, (long long) newsize,

		     (long long) i_size_read(inode));



		/* No need for a higher level metadata lock if we're

		 * never going past i_size. */

		if (newsize <= i_size_read(inode))

			break;



		if (meta_level == 0) {

			ocfs2_meta_unlock(inode, meta_level);

			meta_level = 1;

			continue;

		}



		spin_lock(&OCFS2_I(inode)->ip_lock);

		clusters = ocfs2_clusters_for_bytes(inode->i_sb, newsize) -

			OCFS2_I(inode)->ip_clusters;

		spin_unlock(&OCFS2_I(inode)->ip_lock);



		mlog(0, "Writing at EOF, may need more allocation: "

		     "i_size = %lld, newsize = %lld, need %u clusters\n",

		     (long long) i_size_read(inode), (long long) newsize,

		     clusters);



		/* We only want to continue the rest of this loop if

		 * our extend will actually require more

		 * allocation. */

		if (!clusters)

			break;



		ret = ocfs2_extend_file(inode, NULL, newsize, count);

		if (ret < 0) {

			if (ret != -ENOSPC)

				mlog_errno(ret);

			goto out_unlock;

		}

		break;

	}



	if (appending)

		*ppos = saved_pos;

fs/ocfs2/file.h

+2 −0
Original line number Diff line number Diff line
@@ -47,6 +47,8 @@ int ocfs2_do_extend_allocation(struct ocfs2_super *osb, 
			       struct ocfs2_alloc_context *data_ac,

			       struct ocfs2_alloc_context *meta_ac,

			       enum ocfs2_alloc_restarted *reason_ret);

int ocfs2_extend_no_holes(struct inode *inode, u64 new_i_size,

			  u64 zero_to);

int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_dinode *di,

			  u32 clusters_to_add, u32 extents_to_split,

			  struct ocfs2_alloc_context **data_ac,