Commit 628e366d authored by Andreas Gruenbacher's avatar Andreas Gruenbacher Committed by Bob Peterson
Browse files

gfs2: Iomap cleanups and improvements 



Clean up gfs2_iomap_alloc and gfs2_iomap_get.  Document how
gfs2_iomap_alloc works: it now needs to be called separately after
gfs2_iomap_get where necessary; this will be used later by iomap write.
Move gfs2_iomap_ops into bmap.c.

Introduce a new gfs2_iomap_get_alloc helper and use it in
fallocate_chunk: gfs2_iomap_begin will become unsuitable for fallocate
with proper iomap write support.

In gfs2_block_map and fallocate_chunk, zero-initialize struct iomap.

Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
parent 845802b1

fs/gfs2/bmap.c

+119 −86
Original line number Diff line number Diff line
@@ -572,22 +572,6 @@ static int gfs2_hole_size(struct inode *inode, sector_t lblock, u64 len, 
	return ret;

}



static inline void bmap_lock(struct gfs2_inode *ip, int create)

{

	if (create)

		down_write(&ip->i_rw_mutex);

	else

		down_read(&ip->i_rw_mutex);

}



static inline void bmap_unlock(struct gfs2_inode *ip, int create)

{

	if (create)

		up_write(&ip->i_rw_mutex);

	else

		up_read(&ip->i_rw_mutex);

}



static inline __be64 *gfs2_indirect_init(struct metapath *mp,

					 struct gfs2_glock *gl, unsigned int i,

					 unsigned offset, u64 bn)
@@ -614,15 +598,11 @@ enum alloc_state { 
};



/**

 * gfs2_bmap_alloc - Build a metadata tree of the requested height

 * gfs2_iomap_alloc - Build a metadata tree of the requested height

 * @inode: The GFS2 inode

 * @lblock: The logical starting block of the extent

 * @bh_map: This is used to return the mapping details

 * @zero_new: True if newly allocated blocks should be zeroed

 * @iomap: The iomap structure

 * @flags: iomap flags

 * @mp: The metapath, with proper height information calculated

 * @maxlen: The max number of data blocks to alloc

 * @dblock: Pointer to return the resulting new block

 * @dblks: Pointer to return the number of blocks allocated

 *

 * In this routine we may have to alloc:

 *   i) Indirect blocks to grow the metadata tree height
@@ -635,6 +615,13 @@ enum alloc_state { 
 * blocks are available, there will only be one request per bmap call)

 * and uses the state machine to initialise the blocks in order.

 *

 * Right now, this function will allocate at most one indirect block

 * worth of data -- with a default block size of 4K, that's slightly

 * less than 2M.  If this limitation is ever removed to allow huge

 * allocations, we would probably still want to limit the iomap size we

 * return to avoid stalling other tasks during huge writes; the next

 * iomap iteration would then find the blocks already allocated.

 *

 * Returns: errno on error

 */
@@ -649,6 +636,7 @@ static int gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap, 
	unsigned dblks = 0;

	unsigned ptrs_per_blk;

	const unsigned end_of_metadata = mp->mp_fheight - 1;

	int ret;

	enum alloc_state state;

	__be64 *ptr;

	__be64 zero_bn = 0;
@@ -659,6 +647,8 @@ static int gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap, 


	gfs2_trans_add_meta(ip->i_gl, dibh);



	down_write(&ip->i_rw_mutex);



	if (mp->mp_fheight == mp->mp_aheight) {

		struct buffer_head *bh;

		int eob;
@@ -694,11 +684,10 @@ static int gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap, 
	blks = dblks + iblks;

	i = mp->mp_aheight;

	do {

		int error;

		n = blks - alloced;

		error = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL);

		if (error)

			return error;

		ret = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL);

		if (ret)

			goto out;

		alloced += n;

		if (state != ALLOC_DATA || gfs2_is_jdata(ip))

			gfs2_trans_add_unrevoke(sdp, bn, n);
@@ -754,7 +743,7 @@ static int gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap, 
			dblks = n;

			ptr = metapointer(end_of_metadata, mp);

			iomap->addr = bn << inode->i_blkbits;

			iomap->flags |= IOMAP_F_NEW;

			iomap->flags |= IOMAP_F_MERGED | IOMAP_F_NEW;

			while (n-- > 0)

				*ptr++ = cpu_to_be64(bn++);

			break;
@@ -764,8 +753,10 @@ static int gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap, 
	iomap->length = (u64)dblks << inode->i_blkbits;

	ip->i_height = mp->mp_fheight;

	gfs2_add_inode_blocks(&ip->i_inode, alloced);

	gfs2_dinode_out(ip, mp->mp_bh[0]->b_data);

	return 0;

	gfs2_dinode_out(ip, dibh->b_data);

out:

	up_write(&ip->i_rw_mutex);

	return ret;

}



static void gfs2_stuffed_iomap(struct inode *inode, struct iomap *iomap)
@@ -781,110 +772,130 @@ static void gfs2_stuffed_iomap(struct inode *inode, struct iomap *iomap) 
}



/**

 * gfs2_iomap_begin - Map blocks from an inode to disk blocks

 * gfs2_iomap_get - Map blocks from an inode to disk blocks

 * @inode: The inode

 * @pos: Starting position in bytes

 * @length: Length to map, in bytes

 * @flags: iomap flags

 * @iomap: The iomap structure

 * @mp: The metapath

 *

 * Returns: errno

 */

int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,

		     unsigned flags, struct iomap *iomap)

static int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,

			  unsigned flags, struct iomap *iomap,

			  struct metapath *mp)

{

	struct gfs2_inode *ip = GFS2_I(inode);

	struct gfs2_sbd *sdp = GFS2_SB(inode);

	struct metapath mp = { .mp_aheight = 1, };

	__be64 *ptr;

	sector_t lblock;

	sector_t lend;

	int ret = 0;

	sector_t lblock_stop;

	int ret;

	int eob;

	unsigned int len;

	u64 len;

	struct buffer_head *bh;

	u8 height;



	trace_gfs2_iomap_start(ip, pos, length, flags);

	if (!length) {

		ret = -EINVAL;

		goto out;

	}

	if (!length)

		return -EINVAL;



	if (gfs2_is_stuffed(ip)) {

		if (flags & IOMAP_REPORT) {

			if (pos >= i_size_read(inode))

				return -ENOENT;

			gfs2_stuffed_iomap(inode, iomap);

			if (pos >= iomap->length)

				ret = -ENOENT;

			goto out;

			return 0;

		}

		BUG_ON(!(flags & IOMAP_WRITE));

	}



	lblock = pos >> inode->i_blkbits;

	lend = (pos + length + sdp->sd_sb.sb_bsize - 1) >> inode->i_blkbits;

	len = lend - lblock;



	iomap->offset = lblock << inode->i_blkbits;

	iomap->addr = IOMAP_NULL_ADDR;

	iomap->type = IOMAP_HOLE;

	iomap->length = (u64)(lend - lblock) << inode->i_blkbits;

	iomap->flags = IOMAP_F_MERGED;

	bmap_lock(ip, flags & IOMAP_WRITE);

	lblock_stop = (pos + length - 1) >> inode->i_blkbits;

	len = lblock_stop - lblock + 1;



	down_read(&ip->i_rw_mutex);



	ret = gfs2_meta_inode_buffer(ip, &mp.mp_bh[0]);

	ret = gfs2_meta_inode_buffer(ip, &mp->mp_bh[0]);

	if (ret)

		goto out_release;

		goto unlock;



	height = ip->i_height;

	while ((lblock + 1) * sdp->sd_sb.sb_bsize > sdp->sd_heightsize[height])

		height++;

	find_metapath(sdp, lblock, &mp, height);

	find_metapath(sdp, lblock, mp, height);

	if (height > ip->i_height || gfs2_is_stuffed(ip))

		goto do_alloc;



	ret = lookup_metapath(ip, &mp);

	ret = lookup_metapath(ip, mp);

	if (ret)

		goto out_release;

		goto unlock;



	if (mp.mp_aheight != ip->i_height)

	if (mp->mp_aheight != ip->i_height)

		goto do_alloc;



	ptr = metapointer(ip->i_height - 1, &mp);

	ptr = metapointer(ip->i_height - 1, mp);

	if (*ptr == 0)

		goto do_alloc;



	iomap->type = IOMAP_MAPPED;

	iomap->addr = be64_to_cpu(*ptr) << inode->i_blkbits;

	bh = mp->mp_bh[ip->i_height - 1];

	len = gfs2_extent_length(bh->b_data, bh->b_size, ptr, len, &eob);



	bh = mp.mp_bh[ip->i_height - 1];

	len = gfs2_extent_length(bh->b_data, bh->b_size, ptr, lend - lblock, &eob);

	iomap->addr = be64_to_cpu(*ptr) << inode->i_blkbits;

	iomap->length = len << inode->i_blkbits;

	iomap->type = IOMAP_MAPPED;

	iomap->flags = IOMAP_F_MERGED;

	if (eob)

		iomap->flags |= IOMAP_F_BOUNDARY;

	iomap->length = (u64)len << inode->i_blkbits;



out_release:

	release_metapath(&mp);

	bmap_unlock(ip, flags & IOMAP_WRITE);

out:

	trace_gfs2_iomap_end(ip, iomap, ret);

	iomap->bdev = inode->i_sb->s_bdev;

unlock:

	up_read(&ip->i_rw_mutex);

	return ret;



do_alloc:

	if (flags & IOMAP_WRITE) {

		ret = gfs2_iomap_alloc(inode, iomap, flags, &mp);

	} else if (flags & IOMAP_REPORT) {

	iomap->addr = IOMAP_NULL_ADDR;

	iomap->length = len << inode->i_blkbits;

	iomap->type = IOMAP_HOLE;

	iomap->flags = 0;

	if (flags & IOMAP_REPORT) {

		loff_t size = i_size_read(inode);

		if (pos >= size)

			ret = -ENOENT;

		else if (height <= ip->i_height)

			ret = gfs2_hole_size(inode, lblock, len, &mp, iomap);

		else if (height == ip->i_height)

			ret = gfs2_hole_size(inode, lblock, len, mp, iomap);

		else

			iomap->length = size - pos;

	}

	goto out_release;

	goto out;

}



static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,

			    unsigned flags, struct iomap *iomap)

{

	struct gfs2_inode *ip = GFS2_I(inode);

	struct metapath mp = { .mp_aheight = 1, };

	int ret;



	trace_gfs2_iomap_start(ip, pos, length, flags);

	if (flags & IOMAP_WRITE) {

		ret = gfs2_iomap_get(inode, pos, length, flags, iomap, &mp);

		if (!ret && iomap->type == IOMAP_HOLE)

			ret = gfs2_iomap_alloc(inode, iomap, flags, &mp);

		release_metapath(&mp);

	} else {

		ret = gfs2_iomap_get(inode, pos, length, flags, iomap, &mp);

		release_metapath(&mp);

	}

	trace_gfs2_iomap_end(ip, iomap, ret);

	return ret;

}



const struct iomap_ops gfs2_iomap_ops = {

	.iomap_begin = gfs2_iomap_begin,

};



/**

 * gfs2_block_map - Map one or more blocks of an inode to a disk block

 * @inode: The inode
@@ -910,25 +921,34 @@ int gfs2_block_map(struct inode *inode, sector_t lblock, 
		   struct buffer_head *bh_map, int create)

{

	struct gfs2_inode *ip = GFS2_I(inode);

	struct iomap iomap;

	int ret, flags = 0;

	loff_t pos = (loff_t)lblock << inode->i_blkbits;

	loff_t length = bh_map->b_size;

	struct metapath mp = { .mp_aheight = 1, };

	struct iomap iomap = { };

	int ret;



	clear_buffer_mapped(bh_map);

	clear_buffer_new(bh_map);

	clear_buffer_boundary(bh_map);

	trace_gfs2_bmap(ip, bh_map, lblock, create, 1);



	if (create)

		flags |= IOMAP_WRITE;

	ret = gfs2_iomap_begin(inode, (loff_t)lblock << inode->i_blkbits,

			       bh_map->b_size, flags, &iomap);

	if (ret) {

		if (!create && ret == -ENOENT) {

	if (create) {

		ret = gfs2_iomap_get(inode, pos, length, IOMAP_WRITE, &iomap, &mp);

		if (!ret && iomap.type == IOMAP_HOLE)

			ret = gfs2_iomap_alloc(inode, &iomap, IOMAP_WRITE, &mp);

		release_metapath(&mp);

	} else {

		ret = gfs2_iomap_get(inode, pos, length, 0, &iomap, &mp);

		release_metapath(&mp);



		/* Return unmapped buffer beyond the end of file. */

		if (ret == -ENOENT) {

			ret = 0;

		}

			goto out;

		}

	}

	if (ret)

		goto out;



	if (iomap.length > bh_map->b_size) {

		iomap.length = bh_map->b_size;
@@ -1143,6 +1163,19 @@ out: 
	return error;

}



int gfs2_iomap_get_alloc(struct inode *inode, loff_t pos, loff_t length,

			 struct iomap *iomap)

{

	struct metapath mp = { .mp_aheight = 1, };

	int ret;



	ret = gfs2_iomap_get(inode, pos, length, IOMAP_WRITE, iomap, &mp);

	if (!ret && iomap->type == IOMAP_HOLE)

		ret = gfs2_iomap_alloc(inode, iomap, IOMAP_WRITE, &mp);

	release_metapath(&mp);

	return ret;

}



/**

 * sweep_bh_for_rgrps - find an rgrp in a meta buffer and free blocks therein

 * @ip: inode

fs/gfs2/bmap.h

+4 −2
Original line number Diff line number Diff line
@@ -46,11 +46,13 @@ static inline void gfs2_write_calc_reserv(const struct gfs2_inode *ip, 
	}

}



extern const struct iomap_ops gfs2_iomap_ops;



extern int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page);

extern int gfs2_block_map(struct inode *inode, sector_t lblock,

			  struct buffer_head *bh, int create);

extern int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,

			    unsigned flags, struct iomap *iomap);

extern int gfs2_iomap_get_alloc(struct inode *inode, loff_t pos, loff_t length,

				struct iomap *iomap);

extern int gfs2_extent_map(struct inode *inode, u64 lblock, int *new,

			   u64 *dblock, unsigned *extlen);

extern int gfs2_setattr_size(struct inode *inode, u64 size);

fs/gfs2/file.c

+3 −3
Original line number Diff line number Diff line
@@ -733,7 +733,7 @@ static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len, 
	struct gfs2_inode *ip = GFS2_I(inode);

	loff_t end = offset + len;

	struct buffer_head *dibh;

	struct iomap iomap;

	struct iomap iomap = { };

	int error;



	error = gfs2_meta_inode_buffer(ip, &dibh);
@@ -749,8 +749,8 @@ static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len, 
	}



	while (offset < end) {

		error = gfs2_iomap_begin(inode, offset, end - offset,

					 IOMAP_WRITE, &iomap);

		error = gfs2_iomap_get_alloc(inode, offset, end - offset,

					     &iomap);

		if (error)

			goto out;

		offset = iomap.offset + iomap.length;

fs/gfs2/inode.c

+0 −4
Original line number Diff line number Diff line
@@ -2006,10 +2006,6 @@ static int gfs2_getattr(const struct path *path, struct kstat *stat, 
	return 0;

}



const struct iomap_ops gfs2_iomap_ops = {

	.iomap_begin = gfs2_iomap_begin,

};



static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,

		       u64 start, u64 len)

{

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