diff options
| -rw-r--r-- | fs/gfs2/bmap.c | 51 |
1 files changed, 31 insertions, 20 deletions
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index e983b5872679..1c964def34fd 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -1078,7 +1078,7 @@ out: * @mp: current metapath fully populated with buffers * @btotal: place to keep count of total blocks freed * @hgt: height we're processing - * @first: true if this is the first call to this function for this height + * @keep_start: preserve the first meta pointer * * We sweep a metadata buffer (provided by the metapath) for blocks we need to * free, and free them all. However, we do it one rgrp at a time. If this @@ -1094,7 +1094,7 @@ out: */ static int sweep_bh_for_rgrps(struct gfs2_inode *ip, struct gfs2_holder *rd_gh, const struct metapath *mp, u32 *btotal, int hgt, - bool preserve1) + bool keep_start) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); struct gfs2_rgrpd *rgd; @@ -1119,7 +1119,7 @@ more_rgrps: top = metapointer(hgt, mp); /* first ptr from metapath */ /* If we're keeping some data at the truncation point, we've got to preserve the metadata tree by adding 1 to the starting metapath. */ - if (preserve1) + if (keep_start) top++; bottom = (__be64 *)(bh->b_data + bh->b_size); @@ -1286,9 +1286,9 @@ enum dealloc_states { DEALLOC_DONE = 3, /* process complete */ }; -static bool mp_eq_to_hgt(struct metapath *mp, __u16 *nbof, unsigned int h) +static bool mp_eq_to_hgt(struct metapath *mp, __u16 *list, unsigned int h) { - if (memcmp(mp->mp_list, nbof, h * sizeof(mp->mp_list[0]))) + if (memcmp(mp->mp_list, list, h * sizeof(mp->mp_list[0]))) return false; return true; } @@ -1310,24 +1310,35 @@ static int trunc_dealloc(struct gfs2_inode *ip, u64 newsize) struct metapath mp; struct buffer_head *dibh, *bh; struct gfs2_holder rd_gh; - u64 lblock; - __u16 nbof[GFS2_MAX_META_HEIGHT]; /* new beginning of truncation */ + unsigned int bsize_shift = sdp->sd_sb.sb_bsize_shift; + u64 lblock = (newsize + (1 << bsize_shift) - 1) >> bsize_shift; + __u16 start_list[GFS2_MAX_META_HEIGHT]; /* new beginning of truncation */ + unsigned int start_aligned; unsigned int strip_h = ip->i_height - 1; u32 btotal = 0; int ret, state; int mp_h; /* metapath buffers are read in to this height */ u64 prev_bnr = 0; - bool preserve1; /* need to preserve the first meta pointer? */ - - if (!newsize) - lblock = 0; - else - lblock = (newsize - 1) >> sdp->sd_sb.sb_bsize_shift; + bool keep_start; /* need to preserve the first meta pointer? */ memset(&mp, 0, sizeof(mp)); find_metapath(sdp, lblock, &mp, ip->i_height); - memcpy(&nbof, &mp.mp_list, sizeof(nbof)); + memcpy(start_list, mp.mp_list, sizeof(start_list)); + + /* + * Set start_aligned to the metadata height up to which the truncate + * point is aligned to the metadata tree (i.e., the truncate point is a + * multiple of the granularity at the height above). This determines + * at which heights an additional meta pointer needs to be preserved: + * an additional meta pointer is needed at a given height if + * height < start_aligned. + */ + for (mp_h = ip->i_height - 1; mp_h > 0; mp_h--) { + if (start_list[mp_h]) + break; + } + start_aligned = mp_h; ret = gfs2_meta_inode_buffer(ip, &dibh); if (ret) @@ -1363,10 +1374,6 @@ static int trunc_dealloc(struct gfs2_inode *ip, u64 newsize) /* Truncate a full metapath at the given strip height. * Note that strip_h == mp_h in order to be in this state. */ case DEALLOC_MP_FULL: - /* If we're truncating to a non-zero size and the mp is - at the beginning of file for the strip height, we - need to preserve the first metadata pointer. */ - preserve1 = (newsize && mp_eq_to_hgt(&mp, nbof, mp_h)); bh = mp.mp_bh[mp_h]; gfs2_assert_withdraw(sdp, bh); if (gfs2_assert_withdraw(sdp, @@ -1378,8 +1385,12 @@ static int trunc_dealloc(struct gfs2_inode *ip, u64 newsize) prev_bnr, ip->i_height, strip_h, mp_h); } prev_bnr = bh->b_blocknr; + + keep_start = mp_h < start_aligned && + mp_eq_to_hgt(&mp, start_list, mp_h); + ret = sweep_bh_for_rgrps(ip, &rd_gh, &mp, &btotal, - mp_h, preserve1); + mp_h, keep_start); /* If we hit an error or just swept dinode buffer, just exit. */ if (ret || !mp_h) { @@ -1403,7 +1414,7 @@ static int trunc_dealloc(struct gfs2_inode *ip, u64 newsize) stripping the previous level of metadata. */ if (mp_h == 0) { strip_h--; - memcpy(&mp.mp_list, &nbof, sizeof(nbof)); + memcpy(mp.mp_list, start_list, sizeof(start_list)); mp_h = strip_h; state = DEALLOC_FILL_MP; break; |