From 20cdc1931ee8e03ce3a26061ff14a05a3f8cbe78 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Fri, 22 Sep 2017 07:39:54 -0500 Subject: gfs2: Clarify gfs2_block_map Add a comment about the logical block size for directories. Rename "bsize" in gfs2_block_map to "factor". Fix a typo in the description of metaptr1. Signed-off-by: Andreas Gruenbacher Signed-off-by: Bob Peterson --- fs/gfs2/bmap.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 3dd0cceefa43..8830e2903a34 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -248,7 +248,7 @@ static inline unsigned int metapath_branch_start(const struct metapath *mp) } /** - * metaptr1 - Return the first possible metadata pointer in a metaath buffer + * metaptr1 - Return the first possible metadata pointer in a metapath buffer * @height: The metadata height (0 = dinode) * @mp: The metapath */ @@ -659,7 +659,7 @@ int gfs2_block_map(struct inode *inode, sector_t lblock, { struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); - unsigned int bsize = sdp->sd_sb.sb_bsize; + unsigned int factor = sdp->sd_sb.sb_bsize; const size_t maxlen = bh_map->b_size >> inode->i_blkbits; const u64 *arr = sdp->sd_heightsize; __be64 *ptr; @@ -679,8 +679,14 @@ int gfs2_block_map(struct inode *inode, sector_t lblock, clear_buffer_new(bh_map); clear_buffer_boundary(bh_map); trace_gfs2_bmap(ip, bh_map, lblock, create, 1); + + /* + * Directory data blocks have a struct gfs2_meta_header header, so the + * remaining size is smaller than the filesystem block size. Logical + * block numbers for directories are in units of this remaining size! + */ if (gfs2_is_dir(ip)) { - bsize = sdp->sd_jbsize; + factor = sdp->sd_jbsize; arr = sdp->sd_jheightsize; } @@ -689,7 +695,7 @@ int gfs2_block_map(struct inode *inode, sector_t lblock, goto out; height = ip->i_height; - size = (lblock + 1) * bsize; + size = (lblock + 1) * factor; while (size > arr[height]) height++; find_metapath(sdp, lblock, &mp, height); -- cgit