From: Andreas Gruenbacher Date: Mon, 4 Jun 2018 12:56:51 +0000 (-0500) Subject: gfs2: Iomap cleanups and improvements X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=628e366df11c0a61487522ec1d4bca5c77fe9083;p=openwrt%2Fstaging%2Fblogic.git 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: Andreas Gruenbacher Signed-off-by: Bob Peterson --- diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 5226c3bfbcf7..a7b586e02693 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -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) { - /* Return unmapped buffer beyond the end of file. */ + 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; } - 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 diff --git a/fs/gfs2/bmap.h b/fs/gfs2/bmap.h index c3402fe00653..6b18fb323f0a 100644 --- a/fs/gfs2/bmap.h +++ b/fs/gfs2/bmap.h @@ -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); diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index 4b71f021a9e2..7137db7b0119 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -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; diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c index 8700eb815638..feda55f67050 100644 --- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -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) {