Commit fa731fc4 authored by Steven Whitehouse's avatar Steven Whitehouse
Browse files

GFS2: Fix truncation of journaled data files 



This patch fixes an issue relating to not having enough revokes
available when truncating journaled data files. In order to ensure
that we do no run out, the truncation is broken into separate pieces
if it is large enough.

Tested using fsx on a journaled data file.

Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent 9dbe9610

fs/gfs2/bmap.c

+49 −3
Original line number Diff line number Diff line
@@ -991,6 +991,41 @@ unlock: 
	return err;

}



/**

 * gfs2_journaled_truncate - Wrapper for truncate_pagecache for jdata files

 * @inode: The inode being truncated

 * @oldsize: The original (larger) size

 * @newsize: The new smaller size

 *

 * With jdata files, we have to journal a revoke for each block which is

 * truncated. As a result, we need to split this into separate transactions

 * if the number of pages being truncated gets too large.

 */



#define GFS2_JTRUNC_REVOKES 8192



static int gfs2_journaled_truncate(struct inode *inode, u64 oldsize, u64 newsize)

{

	struct gfs2_sbd *sdp = GFS2_SB(inode);

	u64 max_chunk = GFS2_JTRUNC_REVOKES * sdp->sd_vfs->s_blocksize;

	u64 chunk;

	int error;



	while (oldsize != newsize) {

		chunk = oldsize - newsize;

		if (chunk > max_chunk)

			chunk = max_chunk;

		truncate_pagecache(inode, oldsize, oldsize - chunk);

		oldsize -= chunk;

		gfs2_trans_end(sdp);

		error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES);

		if (error)

			return error;

	}



	return 0;

}



static int trunc_start(struct inode *inode, u64 oldsize, u64 newsize)

{

	struct gfs2_inode *ip = GFS2_I(inode);
@@ -1000,8 +1035,10 @@ static int trunc_start(struct inode *inode, u64 oldsize, u64 newsize) 
	int journaled = gfs2_is_jdata(ip);

	int error;



	error = gfs2_trans_begin(sdp,

				 RES_DINODE + (journaled ? RES_JDATA : 0), 0);

	if (journaled)

		error = gfs2_trans_begin(sdp, RES_DINODE + RES_JDATA, GFS2_JTRUNC_REVOKES);

	else

		error = gfs2_trans_begin(sdp, RES_DINODE, 0);

	if (error)

		return error;
@@ -1026,7 +1063,16 @@ static int trunc_start(struct inode *inode, u64 oldsize, u64 newsize) 
	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;

	gfs2_dinode_out(ip, dibh->b_data);



	if (journaled)

		error = gfs2_journaled_truncate(inode, oldsize, newsize);

	else

		truncate_pagecache(inode, oldsize, newsize);



	if (error) {

		brelse(dibh);

		return error;

	}



out_brelse:

	brelse(dibh);

out:

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