Commit 4e56a641 authored by Andreas Gruenbacher's avatar Andreas Gruenbacher
Browse files

gfs2: Implement fallocate(FALLOC_FL_PUNCH_HOLE) 



Implement the top-level bits of punching a hole into a file.

Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
parent 10d2cf94

fs/gfs2/bmap.c

+121 −1
Original line number Diff line number Diff line
@@ -1351,7 +1351,7 @@ static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length) 
	u64 lblock = (offset + (1 << bsize_shift) - 1) >> bsize_shift;

	__u16 start_list[GFS2_MAX_META_HEIGHT];

	__u16 __end_list[GFS2_MAX_META_HEIGHT], *end_list = NULL;

	unsigned int start_aligned, end_aligned;

	unsigned int start_aligned, uninitialized_var(end_aligned);

	unsigned int strip_h = ip->i_height - 1;

	u32 btotal = 0;

	int ret, state;
@@ -1956,3 +1956,123 @@ int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset, 
	return 0;

}



static int stuffed_zero_range(struct inode *inode, loff_t offset, loff_t length)

{

	struct gfs2_inode *ip = GFS2_I(inode);

	struct buffer_head *dibh;

	int error;



	if (offset >= inode->i_size)

		return 0;

	if (offset + length > inode->i_size)

		length = inode->i_size - offset;



	error = gfs2_meta_inode_buffer(ip, &dibh);

	if (error)

		return error;

	gfs2_trans_add_meta(ip->i_gl, dibh);

	memset(dibh->b_data + sizeof(struct gfs2_dinode) + offset, 0,

	       length);

	brelse(dibh);

	return 0;

}



static int gfs2_journaled_truncate_range(struct inode *inode, loff_t offset,

					 loff_t length)

{

	struct gfs2_sbd *sdp = GFS2_SB(inode);

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

	int error;



	while (length) {

		struct gfs2_trans *tr;

		loff_t chunk;

		unsigned int offs;



		chunk = length;

		if (chunk > max_chunk)

			chunk = max_chunk;



		offs = offset & ~PAGE_MASK;

		if (offs && chunk > PAGE_SIZE)

			chunk = offs + ((chunk - offs) & PAGE_MASK);



		truncate_pagecache_range(inode, offset, chunk);

		offset += chunk;

		length -= chunk;



		tr = current->journal_info;

		if (!test_bit(TR_TOUCHED, &tr->tr_flags))

			continue;



		gfs2_trans_end(sdp);

		error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES);

		if (error)

			return error;

	}

	return 0;

}



int __gfs2_punch_hole(struct file *file, loff_t offset, loff_t length)

{

	struct inode *inode = file_inode(file);

	struct gfs2_inode *ip = GFS2_I(inode);

	struct gfs2_sbd *sdp = GFS2_SB(inode);

	int error;



	if (gfs2_is_jdata(ip))

		error = gfs2_trans_begin(sdp, RES_DINODE + 2 * RES_JDATA,

					 GFS2_JTRUNC_REVOKES);

	else

		error = gfs2_trans_begin(sdp, RES_DINODE, 0);

	if (error)

		return error;



	if (gfs2_is_stuffed(ip)) {

		error = stuffed_zero_range(inode, offset, length);

		if (error)

			goto out;

	} else {

		unsigned int start_off, end_off, blocksize;



		blocksize = i_blocksize(inode);

		start_off = offset & (blocksize - 1);

		end_off = (offset + length) & (blocksize - 1);

		if (start_off) {

			unsigned int len = length;

			if (length > blocksize - start_off)

				len = blocksize - start_off;

			error = gfs2_block_zero_range(inode, offset, len);

			if (error)

				goto out;

			if (start_off + length < blocksize)

				end_off = 0;

		}

		if (end_off) {

			error = gfs2_block_zero_range(inode,

				offset + length - end_off, end_off);

			if (error)

				goto out;

		}

	}



	if (gfs2_is_jdata(ip)) {

		BUG_ON(!current->journal_info);

		gfs2_journaled_truncate_range(inode, offset, length);

	} else

		truncate_pagecache_range(inode, offset, offset + length - 1);



	file_update_time(file);

	mark_inode_dirty(inode);



	if (current->journal_info)

		gfs2_trans_end(sdp);



	if (!gfs2_is_stuffed(ip))

		error = punch_hole(ip, offset, length);



out:

	if (current->journal_info)

		gfs2_trans_end(sdp);

	return error;

}

fs/gfs2/bmap.h

+1 −0
Original line number Diff line number Diff line
@@ -61,5 +61,6 @@ extern int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset, 
				     unsigned int len);

extern int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd);

extern void gfs2_free_journal_extents(struct gfs2_jdesc *jd);

extern int __gfs2_punch_hole(struct file *file, loff_t offset, loff_t length);



#endif /* __BMAP_DOT_H__ */

fs/gfs2/file.c

+12 −7
Original line number Diff line number Diff line
@@ -924,7 +924,7 @@ static long gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t le 
	struct gfs2_holder gh;

	int ret;



	if (mode & ~FALLOC_FL_KEEP_SIZE)

	if (mode & ~(FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE))

		return -EOPNOTSUPP;

	/* fallocate is needed by gfs2_grow to reserve space in the rindex */

	if (gfs2_is_jdata(ip) && inode != sdp->sd_rindex)
@@ -948,13 +948,18 @@ static long gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t le 
	if (ret)

		goto out_unlock;



	if (mode & FALLOC_FL_PUNCH_HOLE) {

		ret = __gfs2_punch_hole(file, offset, len);

	} else {

		ret = gfs2_rsqa_alloc(ip);

		if (ret)

			goto out_putw;



		ret = __gfs2_fallocate(file, mode, offset, len);



		if (ret)

			gfs2_rs_deltree(&ip->i_res);

	}



out_putw:

	put_write_access(inode);