From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bob Peterson Date: Fri, 13 Jul 2018 16:19:13 -0400 (EDT) Subject: [Cluster-devel] [PATCH v2] gfs2: Fix gfs2_testbit to use clone bitmaps In-Reply-To: <1726844332.50526668.1531512206762.JavaMail.zimbra@redhat.com> Message-ID: <805116413.50533265.1531513153795.JavaMail.zimbra@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi, The previous version of my patch had a bug. Apparently function gfs2_check_blk_type does need to check the non-clone bitmap. The other two callers need to check the clone bitmap, if available. So this version adds a parameter to specify. Also, I got rid of function gfs2_get_block_type() in favor of calling it directly from its only caller, gfs2_check_blk_type. This simplifies the code. Bob Peterson --- Function gfs2_testbit is called in three places. Two of those places, gfs2_alloc_extent and gfs2_unaligned_extlen, should be using the clone bitmaps, not the "real" bitmaps. Function gfs2_unaligned_extlen is used by the block reservations scheme to determine the length of an extent of free blocks. Before this patch, it wasn't using the clone bitmap, which means soon-to-be-freed blocks will be treated as free blocks for the purposes of an extent, and that's clearly wrong. This patch adds a new parameter to gfs2_testbit to indicate whether or not the clone bitmaps should be used (if available). Signed-off-by: Bob Peterson --- fs/gfs2/rgrp.c | 45 ++++++++++++++++++++------------------------- 1 file changed, 20 insertions(+), 25 deletions(-) diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 3821b3ab04fa..7e22918d32d6 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -123,17 +123,27 @@ static inline void gfs2_setbit(const struct gfs2_rbm *rbm, bool do_clone, /** * gfs2_testbit - test a bit in the bitmaps * @rbm: The bit to test + * @use_clone: If true, test the clone bitmap, not the official bitmap. + * + * Some callers, like gfs2_unaligned_extlen, need to test the clone bitmaps, + * not the "real" bitmaps, because we can't reserve blocks if they're still + * considered metadata in the journal. * * Returns: The two bit block state of the requested bit */ -static inline u8 gfs2_testbit(const struct gfs2_rbm *rbm) +static inline u8 gfs2_testbit(const struct gfs2_rbm *rbm, bool use_clone) { struct gfs2_bitmap *bi = rbm_bi(rbm); - const u8 *buffer = bi->bi_bh->b_data + bi->bi_offset; + const u8 *buffer; const u8 *byte; unsigned int bit; + if (use_clone && bi->bi_clone) + buffer = bi->bi_clone; + else + buffer = bi->bi_bh->b_data; + buffer += bi->bi_offset; byte = buffer + (rbm->offset / GFS2_NBBY); bit = (rbm->offset % GFS2_NBBY) * GFS2_BIT_SIZE; @@ -322,7 +332,7 @@ static bool gfs2_unaligned_extlen(struct gfs2_rbm *rbm, u32 n_unaligned, u32 *le u8 res; for (n = 0; n < n_unaligned; n++) { - res = gfs2_testbit(rbm); + res = gfs2_testbit(rbm, true); if (res != GFS2_BLKST_FREE) return true; (*len)--; @@ -2142,26 +2152,6 @@ void gfs2_inplace_release(struct gfs2_inode *ip) gfs2_glock_dq_uninit(&rs->rs_rgd_gh); } -/** - * gfs2_get_block_type - Check a block in a RG is of given type - * @rgd: the resource group holding the block - * @block: the block number - * - * Returns: The block type (GFS2_BLKST_*) - */ - -static unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, u64 block) -{ - struct gfs2_rbm rbm = { .rgd = rgd, }; - int ret; - - ret = gfs2_rbm_from_block(&rbm, block); - WARN_ON_ONCE(ret != 0); - - return gfs2_testbit(&rbm); -} - - /** * gfs2_alloc_extent - allocate an extent from a given bitmap * @rbm: the resource group information @@ -2186,7 +2176,7 @@ static void gfs2_alloc_extent(const struct gfs2_rbm *rbm, bool dinode, block++; while (*n < elen) { ret = gfs2_rbm_from_block(&pos, block); - if (ret || gfs2_testbit(&pos) != GFS2_BLKST_FREE) + if (ret || gfs2_testbit(&pos, true) != GFS2_BLKST_FREE) break; gfs2_trans_add_meta(pos.rgd->rd_gl, rbm_bi(&pos)->bi_bh); gfs2_setbit(&pos, true, GFS2_BLKST_USED); @@ -2543,6 +2533,7 @@ int gfs2_check_blk_type(struct gfs2_sbd *sdp, u64 no_addr, unsigned int type) { struct gfs2_rgrpd *rgd; struct gfs2_holder rgd_gh; + struct gfs2_rbm rbm; int error = -EINVAL; rgd = gfs2_blk2rgrpd(sdp, no_addr, 1); @@ -2553,7 +2544,11 @@ int gfs2_check_blk_type(struct gfs2_sbd *sdp, u64 no_addr, unsigned int type) if (error) goto fail; - if (gfs2_get_block_type(rgd, no_addr) != type) + rbm.rgd = rgd; + error = gfs2_rbm_from_block(&rbm, no_addr); + WARN_ON_ONCE(error != 0); + + if (gfs2_testbit(&rbm, false) != type) error = -ESTALE; gfs2_glock_dq_uninit(&rgd_gh);