From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Whitehouse Date: Mon, 21 Nov 2011 18:38:00 +0000 Subject: [Cluster-devel] [GFS2 PATCH TRY2] GFS2: split function rgblk_search In-Reply-To: <05a496f5-daa3-4663-a808-5b35ca173ead@zmail16.collab.prod.int.phx2.redhat.com> References: <05a496f5-daa3-4663-a808-5b35ca173ead@zmail16.collab.prod.int.phx2.redhat.com> Message-ID: <1321900680.2710.54.camel@menhir> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi, I've applied this to the -nmw tree now. Thanks, Steve. On Mon, 2011-11-21 at 11:47 -0500, Bob Peterson wrote: > Hi, > > ----- Original Message ----- > | Since bi is set to NULL above, this could presumably be unconditional > > Yes, bi is initialized to NULL, but it changes within the loop. > I was trying to avoid cases where an error condition occurs > and an extent is not found (as remote as the possibility is) > and yet the last bi is still returned and may be fiddled with. > Since the possibility is remote, I can still remove the if, > or I can leave it in for that reason. Your choice. > > I've implemented your other suggestions, and here is the revised patch: > > Regards, > > Bob Peterson > Red Hat File Systems > > Signed-off-by: Bob Peterson > -- > gfs2: split function rgblk_search > > This patch splits function rgblk_search into a function that finds > blocks to allocate (rgblk_search) and a function that assigns those > blocks (gfs2_alloc_extent). > > diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c > index f1d1960..6b6cc09 100644 > --- a/fs/gfs2/rgrp.c > +++ b/fs/gfs2/rgrp.c > @@ -65,8 +65,8 @@ static const char valid_change[16] = { > }; > > static u32 rgblk_search(struct gfs2_rgrpd *rgd, u32 goal, > - unsigned char old_state, bool dinode, > - unsigned int *ndata); > + unsigned char old_state, bool dinode, > + struct gfs2_bitmap **rbi); > > /** > * gfs2_setbit - Set a bit in the bitmaps > @@ -899,6 +899,11 @@ static int try_rgrp_fit(const struct gfs2_rgrpd *rgd, const struct gfs2_inode *i > return 0; > } > > +static inline u32 gfs2_bi2rgd_blk(struct gfs2_bitmap *bi, u32 blk) > +{ > + return (bi->bi_start * GFS2_NBBY) + blk; > +} > + > /** > * try_rgrp_unlink - Look for any unlinked, allocated, but unused inodes > * @rgd: The rgrp > @@ -912,19 +917,20 @@ static void try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked, u64 skip > u32 goal = 0, block; > u64 no_addr; > struct gfs2_sbd *sdp = rgd->rd_sbd; > - unsigned int n; > struct gfs2_glock *gl; > struct gfs2_inode *ip; > int error; > int found = 0; > + struct gfs2_bitmap *bi; > > while (goal < rgd->rd_data) { > down_write(&sdp->sd_log_flush_lock); > - n = 1; > - block = rgblk_search(rgd, goal, GFS2_BLKST_UNLINKED, 0, &n); > + block = rgblk_search(rgd, goal, GFS2_BLKST_UNLINKED, 0, &bi); > up_write(&sdp->sd_log_flush_lock); > if (block == BFITNOENT) > break; > + > + block = gfs2_bi2rgd_blk(bi, block); > /* rgblk_search can return a block < goal, so we need to > keep it marching forward. */ > no_addr = block + rgd->rd_data0; > @@ -1109,38 +1115,35 @@ static unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, u64 block) > } > > /** > - * rgblk_search - find a block in @old_state, change allocation > - * state to @new_state > + * rgblk_search - find a block in @old_state > * @rgd: the resource group descriptor > * @goal: the goal block within the RG (start here to search for avail block) > * @old_state: GFS2_BLKST_XXX the before-allocation state to find > * @dinode: TRUE if the first block we allocate is for a dinode > - * @n: The extent length > + * @rbi: address of the pointer to the bitmap containing the block found > * > * Walk rgrp's bitmap to find bits that represent a block in @old_state. > - * Add the found bitmap buffer to the transaction. > - * Set the found bits to @new_state to change block's allocation state. > * > * This function never fails, because we wouldn't call it unless we > * know (from reservation results, etc.) that a block is available. > * > - * Scope of @goal and returned block is just within rgrp, not the whole > - * filesystem. > + * Scope of @goal is just within rgrp, not the whole filesystem. > + * Scope of @returned block is just within bitmap, not the whole filesystem. > * > - * Returns: the block number allocated > + * Returns: the block number found relative to the bitmap rbi > */ > > static u32 rgblk_search(struct gfs2_rgrpd *rgd, u32 goal, > - unsigned char old_state, bool dinode, unsigned int *n) > + unsigned char old_state, bool dinode, > + struct gfs2_bitmap **rbi) > { > struct gfs2_bitmap *bi = NULL; > const u32 length = rgd->rd_length; > u32 blk = BFITNOENT; > unsigned int buf, x; > - const unsigned int elen = *n; > const u8 *buffer = NULL; > > - *n = 0; > + *rbi = NULL; > /* Find bitmap block that contains bits for goal block */ > for (buf = 0; buf < length; buf++) { > bi = rgd->rd_bits + buf; > @@ -1187,12 +1190,32 @@ skip: > goal = 0; > } > > - if (blk == BFITNOENT) > - return blk; > + if (blk != BFITNOENT) > + *rbi = bi; > > - if (old_state == GFS2_BLKST_UNLINKED) > - goto out; > + return blk; > +} > > +/** > + * gfs2_alloc_extent - allocate an extent from a given bitmap > + * @rgd: the resource group descriptor > + * @bi: the bitmap within the rgrp > + * @blk: the block within the bitmap > + * @dinode: TRUE if the first block we allocate is for a dinode > + * @n: The extent length > + * > + * Add the found bitmap buffer to the transaction. > + * Set the found bits to @new_state to change block's allocation state. > + * Returns: starting block number of the extent (fs scope) > + */ > +static u64 gfs2_alloc_extent(struct gfs2_rgrpd *rgd, struct gfs2_bitmap *bi, > + u32 blk, bool dinode, unsigned int *n) > +{ > + const unsigned int elen = *n; > + u32 goal; > + const u8 *buffer = NULL; > + > + buffer = bi->bi_bh->b_data + bi->bi_offset; > gfs2_trans_add_bh(rgd->rd_gl, bi->bi_bh, 1); > gfs2_setbit(rgd, bi->bi_bh->b_data, bi->bi_clone, bi->bi_offset, > bi, blk, dinode ? GFS2_BLKST_DINODE : GFS2_BLKST_USED); > @@ -1210,8 +1233,9 @@ skip: > bi, goal, GFS2_BLKST_USED); > (*n)++; > } > -out: > - return (bi->bi_start * GFS2_NBBY) + blk; > + blk = gfs2_bi2rgd_blk(bi, blk); > + rgd->rd_last_alloc = blk; > + return rgd->rd_data0 + blk; > } > > /** > @@ -1319,6 +1343,7 @@ int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *ndata, > u32 goal, extlen, blk; /* block, within the rgrp scope */ > u64 block; /* block, within the file system scope */ > int error; > + struct gfs2_bitmap *bi; > > /* Only happens if there is a bug in gfs2, return something distinctive > * to ensure that it is noticed. > @@ -1333,14 +1358,15 @@ int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *ndata, > else > goal = rgd->rd_last_alloc; > > - blk = rgblk_search(rgd, goal, GFS2_BLKST_FREE, dinode, ndata); > + blk = rgblk_search(rgd, goal, GFS2_BLKST_FREE, dinode, &bi); > > + *ndata = 0; > /* Since all blocks are reserved in advance, this shouldn't happen */ > if (blk == BFITNOENT) > goto rgrp_error; > > - rgd->rd_last_alloc = blk; > - block = rgd->rd_data0 + blk; > + block = gfs2_alloc_extent(rgd, bi, blk, dinode, ndata); > + > if (!dinode) { > ip->i_goal = block + *ndata - 1; > error = gfs2_meta_inode_buffer(ip, &dibh);