Code that manages block allocation. Signed-off-by: Ken Preslan <[EMAIL PROTECTED]> Signed-off-by: David Teigland <[EMAIL PROTECTED]>
--- fs/gfs2/bits.c | 179 +++++++ fs/gfs2/bits.h | 28 + fs/gfs2/rgrp.c | 1374 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/gfs2/rgrp.h | 62 ++ 4 files changed, 1643 insertions(+) --- a/fs/gfs2/rgrp.c 1970-01-01 07:30:00.000000000 +0730 +++ b/fs/gfs2/rgrp.c 2005-09-01 17:36:55.478090696 +0800 @@ -0,0 +1,1374 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. + * + * This copyrighted material is made available to anyone wishing to use, + * modify, copy, or redistribute it subject to the terms and conditions + * of the GNU General Public License v.2. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/smp_lock.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <asm/semaphore.h> + +#include "gfs2.h" +#include "bits.h" +#include "glock.h" +#include "glops.h" +#include "jdata.h" +#include "lops.h" +#include "meta_io.h" +#include "quota.h" +#include "rgrp.h" +#include "super.h" +#include "trans.h" + +/** + * gfs2_rgrp_verify - Verify that a resource group is consistent + * @sdp: the filesystem + * @rgd: the rgrp + * + */ + +void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd) +{ + struct gfs2_sbd *sdp = rgd->rd_sbd; + struct gfs2_bitmap *bi = NULL; + uint32_t length = rgd->rd_ri.ri_length; + uint32_t count[4], tmp; + int buf, x; + + memset(count, 0, 4 * sizeof(uint32_t)); + + /* Count # blocks in each of 4 possible allocation states */ + for (buf = 0; buf < length; buf++) { + bi = rgd->rd_bits + buf; + for (x = 0; x < 4; x++) + count[x] += gfs2_bitcount(rgd, + bi->bi_bh->b_data + + bi->bi_offset, + bi->bi_len, x); + } + + if (count[0] != rgd->rd_rg.rg_free) { + if (gfs2_consist_rgrpd(rgd)) + fs_err(sdp, "free data mismatch: %u != %u\n", + count[0], rgd->rd_rg.rg_free); + return; + } + + tmp = rgd->rd_ri.ri_data - + rgd->rd_rg.rg_free - + rgd->rd_rg.rg_dinodes; + if (count[1] != tmp) { + if (gfs2_consist_rgrpd(rgd)) + fs_err(sdp, "used data mismatch: %u != %u\n", + count[1], tmp); + return; + } + + if (count[2]) { + if (gfs2_consist_rgrpd(rgd)) + fs_err(sdp, "free metadata mismatch: %u != 0\n", + count[2]); + return; + } + + if (count[3] != rgd->rd_rg.rg_dinodes) { + if (gfs2_consist_rgrpd(rgd)) + fs_err(sdp, "used metadata mismatch: %u != %u\n", + count[3], rgd->rd_rg.rg_dinodes); + return; + } +} + +static inline int rgrp_contains_block(struct gfs2_rindex *ri, uint64_t block) +{ + uint64_t first = ri->ri_data0; + uint64_t last = first + ri->ri_data; + return !!(first <= block && block < last); +} + +/** + * gfs2_blk2rgrpd - Find resource group for a given data/meta block number + * @sdp: The GFS2 superblock + * @n: The data block number + * + * Returns: The resource group, or NULL if not found + */ + +struct gfs2_rgrpd *gfs2_blk2rgrpd(struct gfs2_sbd *sdp, uint64_t blk) +{ + struct gfs2_rgrpd *rgd; + + spin_lock(&sdp->sd_rindex_spin); + + list_for_each_entry(rgd, &sdp->sd_rindex_mru_list, rd_list_mru) { + if (rgrp_contains_block(&rgd->rd_ri, blk)) { + list_move(&rgd->rd_list_mru, &sdp->sd_rindex_mru_list); + spin_unlock(&sdp->sd_rindex_spin); + return rgd; + } + } + + spin_unlock(&sdp->sd_rindex_spin); + + return NULL; +} + +/** + * gfs2_rgrpd_get_first - get the first Resource Group in the filesystem + * @sdp: The GFS2 superblock + * + * Returns: The first rgrp in the filesystem + */ + +struct gfs2_rgrpd *gfs2_rgrpd_get_first(struct gfs2_sbd *sdp) +{ + gfs2_assert(sdp, !list_empty(&sdp->sd_rindex_list),); + return list_entry(sdp->sd_rindex_list.next, struct gfs2_rgrpd, rd_list); +} + +/** + * gfs2_rgrpd_get_next - get the next RG + * @rgd: A RG + * + * Returns: The next rgrp + */ + +struct gfs2_rgrpd *gfs2_rgrpd_get_next(struct gfs2_rgrpd *rgd) +{ + if (rgd->rd_list.next == &rgd->rd_sbd->sd_rindex_list) + return NULL; + return list_entry(rgd->rd_list.next, struct gfs2_rgrpd, rd_list); +} + +static void clear_rgrpdi(struct gfs2_sbd *sdp) +{ + struct list_head *head; + struct gfs2_rgrpd *rgd; + struct gfs2_glock *gl; + + spin_lock(&sdp->sd_rindex_spin); + sdp->sd_rindex_forward = NULL; + head = &sdp->sd_rindex_recent_list; + while (!list_empty(head)) { + rgd = list_entry(head->next, struct gfs2_rgrpd, rd_recent); + list_del(&rgd->rd_recent); + } + spin_unlock(&sdp->sd_rindex_spin); + + head = &sdp->sd_rindex_list; + while (!list_empty(head)) { + rgd = list_entry(head->next, struct gfs2_rgrpd, rd_list); + gl = rgd->rd_gl; + + list_del(&rgd->rd_list); + list_del(&rgd->rd_list_mru); + + if (gl) { + set_gl2rgd(gl, NULL); + gfs2_glock_put(gl); + } + + kfree(rgd->rd_bits); + kfree(rgd); + } +} + +void gfs2_clear_rgrpd(struct gfs2_sbd *sdp) +{ + down(&sdp->sd_rindex_mutex); + clear_rgrpdi(sdp); + up(&sdp->sd_rindex_mutex); +} + +/** + * gfs2_compute_bitstructs - Compute the bitmap sizes + * @rgd: The resource group descriptor + * + * Calculates bitmap descriptors, one for each block that contains bitmap data + * + * Returns: errno + */ + +static int compute_bitstructs(struct gfs2_rgrpd *rgd) +{ + struct gfs2_sbd *sdp = rgd->rd_sbd; + struct gfs2_bitmap *bi; + uint32_t length = rgd->rd_ri.ri_length; /* # blocks in hdr & bitmap */ + uint32_t bytes_left, bytes; + int x; + + rgd->rd_bits = kcalloc(length, sizeof(struct gfs2_bitmap), GFP_KERNEL); + if (!rgd->rd_bits) + return -ENOMEM; + + bytes_left = rgd->rd_ri.ri_bitbytes; + + for (x = 0; x < length; x++) { + bi = rgd->rd_bits + x; + + /* small rgrp; bitmap stored completely in header block */ + if (length == 1) { + bytes = bytes_left; + bi->bi_offset = sizeof(struct gfs2_rgrp); + bi->bi_start = 0; + bi->bi_len = bytes; + /* header block */ + } else if (x == 0) { + bytes = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_rgrp); + bi->bi_offset = sizeof(struct gfs2_rgrp); + bi->bi_start = 0; + bi->bi_len = bytes; + /* last block */ + } else if (x + 1 == length) { + bytes = bytes_left; + bi->bi_offset = sizeof(struct gfs2_meta_header); + bi->bi_start = rgd->rd_ri.ri_bitbytes - bytes_left; + bi->bi_len = bytes; + /* other blocks */ + } else { + bytes = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header); + bi->bi_offset = sizeof(struct gfs2_meta_header); + bi->bi_start = rgd->rd_ri.ri_bitbytes - bytes_left; + bi->bi_len = bytes; + } + + bytes_left -= bytes; + } + + if (bytes_left) { + gfs2_consist_rgrpd(rgd); + return -EIO; + } + bi = rgd->rd_bits + (length - 1); + if ((bi->bi_start + bi->bi_len) * GFS2_NBBY != rgd->rd_ri.ri_data) { + if (gfs2_consist_rgrpd(rgd)) { + gfs2_rindex_print(&rgd->rd_ri); + fs_err(sdp, "start=%u len=%u offset=%u\n", + bi->bi_start, bi->bi_len, bi->bi_offset); + } + return -EIO; + } + + return 0; +} + +/** + * gfs2_ri_update - Pull in a new resource index from the disk + * @gl: The glock covering the rindex inode + * + * Returns: 0 on successful update, error code otherwise + */ + +static int gfs2_ri_update(struct gfs2_inode *ip) +{ + struct gfs2_sbd *sdp = ip->i_sbd; + struct gfs2_rgrpd *rgd; + char buf[sizeof(struct gfs2_rindex)]; + uint64_t junk = ip->i_di.di_size; + int error; + + if (do_div(junk, sizeof(struct gfs2_rindex))) { + gfs2_consist_inode(ip); + return -EIO; + } + + clear_rgrpdi(sdp); + + for (sdp->sd_rgrps = 0;; sdp->sd_rgrps++) { + error = gfs2_jdata_read_mem(ip, buf, + sdp->sd_rgrps * + sizeof(struct gfs2_rindex), + sizeof(struct gfs2_rindex)); + if (!error) + break; + if (error != sizeof(struct gfs2_rindex)) { + if (error > 0) + error = -EIO; + goto fail; + } + + rgd = kzalloc(sizeof(struct gfs2_rgrpd), GFP_KERNEL); + error = -ENOMEM; + if (!rgd) + goto fail; + + init_MUTEX(&rgd->rd_mutex); + lops_init_le(&rgd->rd_le, &gfs2_rg_lops); + rgd->rd_sbd = sdp; + + list_add_tail(&rgd->rd_list, &sdp->sd_rindex_list); + list_add_tail(&rgd->rd_list_mru, &sdp->sd_rindex_mru_list); + + gfs2_rindex_in(&rgd->rd_ri, buf); + + error = compute_bitstructs(rgd); + if (error) + goto fail; + + error = gfs2_glock_get(sdp, rgd->rd_ri.ri_addr, + &gfs2_rgrp_glops, CREATE, &rgd->rd_gl); + if (error) + goto fail; + + set_gl2rgd(rgd->rd_gl, rgd); + rgd->rd_rg_vn = rgd->rd_gl->gl_vn - 1; + } + + sdp->sd_rindex_vn = ip->i_gl->gl_vn; + + return 0; + + fail: + clear_rgrpdi(sdp); + + return error; +} + +/** + * gfs2_rindex_hold - Grab a lock on the rindex + * @sdp: The GFS2 superblock + * @ri_gh: the glock holder + * + * We grab a lock on the rindex inode to make sure that it doesn't + * change whilst we are performing an operation. We keep this lock + * for quite long periods of time compared to other locks. This + * doesn't matter, since it is shared and it is very, very rarely + * accessed in the exclusive mode (i.e. only when expanding the filesystem). + * + * This makes sure that we're using the latest copy of the resource index + * special file, which might have been updated if someone expanded the + * filesystem (via gfs2_grow utility), which adds new resource groups. + * + * Returns: 0 on success, error code otherwise + */ + +int gfs2_rindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ri_gh) +{ + struct gfs2_inode *ip = sdp->sd_rindex; + struct gfs2_glock *gl = ip->i_gl; + int error; + + error = gfs2_glock_nq_init(gl, LM_ST_SHARED, 0, ri_gh); + if (error) + return error; + + /* Read new copy from disk if we don't have the latest */ + if (sdp->sd_rindex_vn != gl->gl_vn) { + down(&sdp->sd_rindex_mutex); + if (sdp->sd_rindex_vn != gl->gl_vn) { + error = gfs2_ri_update(ip); + if (error) + gfs2_glock_dq_uninit(ri_gh); + } + up(&sdp->sd_rindex_mutex); + } + + return error; +} + +/** + * gfs2_rgrp_bh_get - Read in a RG's header and bitmaps + * @rgd: the struct gfs2_rgrpd describing the RG to read in + * + * Read in all of a Resource Group's header and bitmap blocks. + * Caller must eventually call gfs2_rgrp_relse() to free the bitmaps. + * + * Returns: errno + */ + +int gfs2_rgrp_bh_get(struct gfs2_rgrpd *rgd) +{ + struct gfs2_sbd *sdp = rgd->rd_sbd; + struct gfs2_glock *gl = rgd->rd_gl; + unsigned int length = rgd->rd_ri.ri_length; + struct gfs2_bitmap *bi; + unsigned int x, y; + int error; + + down(&rgd->rd_mutex); + + spin_lock(&sdp->sd_rindex_spin); + if (rgd->rd_bh_count) { + rgd->rd_bh_count++; + spin_unlock(&sdp->sd_rindex_spin); + up(&rgd->rd_mutex); + return 0; + } + spin_unlock(&sdp->sd_rindex_spin); + + for (x = 0; x < length; x++) { + bi = rgd->rd_bits + x; + error = gfs2_meta_read(gl, rgd->rd_ri.ri_addr + x, DIO_START, + &bi->bi_bh); + if (error) + goto fail; + } + + for (y = length; y--;) { + bi = rgd->rd_bits + y; + error = gfs2_meta_reread(sdp, bi->bi_bh, DIO_WAIT); + if (error) + goto fail; + if (gfs2_metatype_check(sdp, bi->bi_bh, + (y) ? GFS2_METATYPE_RB : + GFS2_METATYPE_RG)) { + error = -EIO; + goto fail; + } + } + + if (rgd->rd_rg_vn != gl->gl_vn) { + gfs2_rgrp_in(&rgd->rd_rg, (rgd->rd_bits[0].bi_bh)->b_data); + rgd->rd_rg_vn = gl->gl_vn; + } + + spin_lock(&sdp->sd_rindex_spin); + rgd->rd_free_clone = rgd->rd_rg.rg_free; + rgd->rd_bh_count++; + spin_unlock(&sdp->sd_rindex_spin); + + up(&rgd->rd_mutex); + + return 0; + + fail: + while (x--) { + bi = rgd->rd_bits + x; + brelse(bi->bi_bh); + bi->bi_bh = NULL; + gfs2_assert_warn(sdp, !bi->bi_clone); + } + up(&rgd->rd_mutex); + + return error; +} + +void gfs2_rgrp_bh_hold(struct gfs2_rgrpd *rgd) +{ + struct gfs2_sbd *sdp = rgd->rd_sbd; + + spin_lock(&sdp->sd_rindex_spin); + gfs2_assert_warn(rgd->rd_sbd, rgd->rd_bh_count); + rgd->rd_bh_count++; + spin_unlock(&sdp->sd_rindex_spin); +} + +/** + * gfs2_rgrp_bh_put - Release RG bitmaps read in with gfs2_rgrp_bh_get() + * @rgd: the struct gfs2_rgrpd describing the RG to read in + * + */ + +void gfs2_rgrp_bh_put(struct gfs2_rgrpd *rgd) +{ + struct gfs2_sbd *sdp = rgd->rd_sbd; + int x, length = rgd->rd_ri.ri_length; + + spin_lock(&sdp->sd_rindex_spin); + gfs2_assert_warn(rgd->rd_sbd, rgd->rd_bh_count); + if (--rgd->rd_bh_count) { + spin_unlock(&sdp->sd_rindex_spin); + return; + } + + for (x = 0; x < length; x++) { + struct gfs2_bitmap *bi = rgd->rd_bits + x; + kfree(bi->bi_clone); + bi->bi_clone = NULL; + brelse(bi->bi_bh); + bi->bi_bh = NULL; + } + + spin_unlock(&sdp->sd_rindex_spin); +} + +void gfs2_rgrp_repolish_clones(struct gfs2_rgrpd *rgd) +{ + struct gfs2_sbd *sdp = rgd->rd_sbd; + unsigned int length = rgd->rd_ri.ri_length; + unsigned int x; + + for (x = 0; x < length; x++) { + struct gfs2_bitmap *bi = rgd->rd_bits + x; + if (!bi->bi_clone) + continue; + memcpy(bi->bi_clone + bi->bi_offset, + bi->bi_bh->b_data + bi->bi_offset, + bi->bi_len); + } + + spin_lock(&sdp->sd_rindex_spin); + rgd->rd_free_clone = rgd->rd_rg.rg_free; + spin_unlock(&sdp->sd_rindex_spin); +} + +/** + * gfs2_alloc_get - allocate a struct gfs2_alloc structure for an inode + * @ip: the incore GFS2 inode structure + * + * FIXME: Don't use NOFAIL + * + * Returns: the struct gfs2_alloc + */ + +struct gfs2_alloc *gfs2_alloc_get(struct gfs2_inode *ip) +{ + struct gfs2_alloc *al = ip->i_alloc; + + gfs2_assert_warn(ip->i_sbd, !al); + + al = kzalloc(sizeof(struct gfs2_alloc), GFP_KERNEL | __GFP_NOFAIL); + + ip->i_alloc = al; + + return al; +} + +/** + * gfs2_alloc_put - throw away the struct gfs2_alloc for an inode + * @ip: the inode + * + */ + +void gfs2_alloc_put(struct gfs2_inode *ip) +{ + struct gfs2_alloc *al = ip->i_alloc; + + if (gfs2_assert_warn(ip->i_sbd, al)) + return; + + ip->i_alloc = NULL; + kfree(al); +} + +/** + * try_rgrp_fit - See if a given reservation will fit in a given RG + * @rgd: the RG data + * @al: the struct gfs2_alloc structure describing the reservation + * + * If there's room for the requested blocks to be allocated from the RG: + * Sets the $al_reserved_data field in @al. + * Sets the $al_reserved_meta field in @al. + * Sets the $al_rgd field in @al. + * + * Returns: 1 on success (it fits), 0 on failure (it doesn't fit) + */ + +static int try_rgrp_fit(struct gfs2_rgrpd *rgd, struct gfs2_alloc *al) +{ + struct gfs2_sbd *sdp = rgd->rd_sbd; + int ret = 0; + + spin_lock(&sdp->sd_rindex_spin); + if (rgd->rd_free_clone >= al->al_requested) { + al->al_rgd = rgd; + ret = 1; + } + spin_unlock(&sdp->sd_rindex_spin); + + return ret; +} + +/** + * recent_rgrp_first - get first RG from "recent" list + * @sdp: The GFS2 superblock + * @rglast: address of the rgrp used last + * + * Returns: The first rgrp in the recent list + */ + +static struct gfs2_rgrpd *recent_rgrp_first(struct gfs2_sbd *sdp, + uint64_t rglast) +{ + struct gfs2_rgrpd *rgd = NULL; + + spin_lock(&sdp->sd_rindex_spin); + + if (list_empty(&sdp->sd_rindex_recent_list)) + goto out; + + if (!rglast) + goto first; + + list_for_each_entry(rgd, &sdp->sd_rindex_recent_list, rd_recent) { + if (rgd->rd_ri.ri_addr == rglast) + goto out; + } + + first: + rgd = list_entry(sdp->sd_rindex_recent_list.next, struct gfs2_rgrpd, + rd_recent); + + out: + spin_unlock(&sdp->sd_rindex_spin); + + return rgd; +} + +/** + * recent_rgrp_next - get next RG from "recent" list + * @cur_rgd: current rgrp + * @remove: + * + * Returns: The next rgrp in the recent list + */ + +static struct gfs2_rgrpd *recent_rgrp_next(struct gfs2_rgrpd *cur_rgd, + int remove) +{ + struct gfs2_sbd *sdp = cur_rgd->rd_sbd; + struct list_head *head; + struct gfs2_rgrpd *rgd; + + spin_lock(&sdp->sd_rindex_spin); + + head = &sdp->sd_rindex_recent_list; + + list_for_each_entry(rgd, head, rd_recent) { + if (rgd == cur_rgd) { + if (cur_rgd->rd_recent.next != head) + rgd = list_entry(cur_rgd->rd_recent.next, + struct gfs2_rgrpd, rd_recent); + else + rgd = NULL; + + if (remove) + list_del(&cur_rgd->rd_recent); + + goto out; + } + } + + rgd = NULL; + if (!list_empty(head)) + rgd = list_entry(head->next, struct gfs2_rgrpd, rd_recent); + + out: + spin_unlock(&sdp->sd_rindex_spin); + + return rgd; +} + +/** + * recent_rgrp_add - add an RG to tail of "recent" list + * @new_rgd: The rgrp to add + * + */ + +static void recent_rgrp_add(struct gfs2_rgrpd *new_rgd) +{ + struct gfs2_sbd *sdp = new_rgd->rd_sbd; + struct gfs2_rgrpd *rgd; + unsigned int count = 0; + unsigned int max = sdp->sd_rgrps / gfs2_jindex_size(sdp); + + spin_lock(&sdp->sd_rindex_spin); + + list_for_each_entry(rgd, &sdp->sd_rindex_recent_list, rd_recent) { + if (rgd == new_rgd) + goto out; + + if (++count >= max) + goto out; + } + list_add_tail(&new_rgd->rd_recent, &sdp->sd_rindex_recent_list); + + out: + spin_unlock(&sdp->sd_rindex_spin); +} + +/** + * forward_rgrp_get - get an rgrp to try next from full list + * @sdp: The GFS2 superblock + * + * Returns: The rgrp to try next + */ + +static struct gfs2_rgrpd *forward_rgrp_get(struct gfs2_sbd *sdp) +{ + struct gfs2_rgrpd *rgd; + unsigned int journals = gfs2_jindex_size(sdp); + unsigned int rg = 0, x; + + spin_lock(&sdp->sd_rindex_spin); + + rgd = sdp->sd_rindex_forward; + if (!rgd) { + if (sdp->sd_rgrps >= journals) + rg = sdp->sd_rgrps * sdp->sd_jdesc->jd_jid / journals; + + for (x = 0, rgd = gfs2_rgrpd_get_first(sdp); + x < rg; + x++, rgd = gfs2_rgrpd_get_next(rgd)) + /* Do Nothing */; + + sdp->sd_rindex_forward = rgd; + } + + spin_unlock(&sdp->sd_rindex_spin); + + return rgd; +} + +/** + * forward_rgrp_set - set the forward rgrp pointer + * @sdp: the filesystem + * @rgd: The new forward rgrp + * + */ + +static void forward_rgrp_set(struct gfs2_sbd *sdp, struct gfs2_rgrpd *rgd) +{ + spin_lock(&sdp->sd_rindex_spin); + sdp->sd_rindex_forward = rgd; + spin_unlock(&sdp->sd_rindex_spin); +} + +/** + * get_local_rgrp - Choose and lock a rgrp for allocation + * @ip: the inode to reserve space for + * @rgp: the chosen and locked rgrp + * + * Try to acquire rgrp in way which avoids contending with others. + * + * Returns: errno + */ + +static int get_local_rgrp(struct gfs2_inode *ip) +{ + struct gfs2_sbd *sdp = ip->i_sbd; + struct gfs2_rgrpd *rgd, *begin = NULL; + struct gfs2_alloc *al = ip->i_alloc; + int flags = LM_FLAG_TRY; + int skipped = 0; + int loops = 0; + int error; + + /* Try recently successful rgrps */ + + rgd = recent_rgrp_first(sdp, ip->i_last_rg_alloc); + + while (rgd) { + error = gfs2_glock_nq_init(rgd->rd_gl, + LM_ST_EXCLUSIVE, LM_FLAG_TRY, + &al->al_rgd_gh); + switch (error) { + case 0: + if (try_rgrp_fit(rgd, al)) + goto out; + gfs2_glock_dq_uninit(&al->al_rgd_gh); + rgd = recent_rgrp_next(rgd, TRUE); + break; + + case GLR_TRYFAILED: + rgd = recent_rgrp_next(rgd, FALSE); + break; + + default: + return error; + } + } + + /* Go through full list of rgrps */ + + begin = rgd = forward_rgrp_get(sdp); + + for (;;) { + error = gfs2_glock_nq_init(rgd->rd_gl, + LM_ST_EXCLUSIVE, flags, + &al->al_rgd_gh); + switch (error) { + case 0: + if (try_rgrp_fit(rgd, al)) + goto out; + gfs2_glock_dq_uninit(&al->al_rgd_gh); + break; + + case GLR_TRYFAILED: + skipped++; + break; + + default: + return error; + } + + rgd = gfs2_rgrpd_get_next(rgd); + if (!rgd) + rgd = gfs2_rgrpd_get_first(sdp); + + if (rgd == begin) { + if (++loops >= 2 || !skipped) + return -ENOSPC; + flags = 0; + } + } + + out: + ip->i_last_rg_alloc = rgd->rd_ri.ri_addr; + + if (begin) { + recent_rgrp_add(rgd); + rgd = gfs2_rgrpd_get_next(rgd); + if (!rgd) + rgd = gfs2_rgrpd_get_first(sdp); + forward_rgrp_set(sdp, rgd); + } + + return 0; +} + +/** + * gfs2_inplace_reserve_i - Reserve space in the filesystem + * @ip: the inode to reserve space for + * + * Returns: errno + */ + +int gfs2_inplace_reserve_i(struct gfs2_inode *ip, char *file, unsigned int line) +{ + struct gfs2_sbd *sdp = ip->i_sbd; + struct gfs2_alloc *al = ip->i_alloc; + int error; + + if (gfs2_assert_warn(sdp, al->al_requested)) + return -EINVAL; + + error = gfs2_rindex_hold(sdp, &al->al_ri_gh); + if (error) + return error; + + error = get_local_rgrp(ip); + if (error) { + gfs2_glock_dq_uninit(&al->al_ri_gh); + return error; + } + + al->al_file = file; + al->al_line = line; + + return 0; +} + +/** + * gfs2_inplace_release - release an inplace reservation + * @ip: the inode the reservation was taken out on + * + * Release a reservation made by gfs2_inplace_reserve(). + */ + +void gfs2_inplace_release(struct gfs2_inode *ip) +{ + struct gfs2_sbd *sdp = ip->i_sbd; + struct gfs2_alloc *al = ip->i_alloc; + + if (gfs2_assert_warn(sdp, al->al_alloced <= al->al_requested) == -1) + fs_warn(sdp, "al_alloced = %u, al_requested = %u " + "al_file = %s, al_line = %u\n", + al->al_alloced, al->al_requested, al->al_file, + al->al_line); + + al->al_rgd = NULL; + gfs2_glock_dq_uninit(&al->al_rgd_gh); + gfs2_glock_dq_uninit(&al->al_ri_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_*) + */ + +unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, uint64_t block) +{ + struct gfs2_bitmap *bi = NULL; + uint32_t length, rgrp_block, buf_block; + unsigned int buf; + unsigned char type; + + length = rgd->rd_ri.ri_length; + rgrp_block = block - rgd->rd_ri.ri_data0; + + for (buf = 0; buf < length; buf++) { + bi = rgd->rd_bits + buf; + if (rgrp_block < (bi->bi_start + bi->bi_len) * GFS2_NBBY) + break; + } + + gfs2_assert(rgd->rd_sbd, buf < length,); + buf_block = rgrp_block - bi->bi_start * GFS2_NBBY; + + type = gfs2_testbit(rgd, + bi->bi_bh->b_data + bi->bi_offset, + bi->bi_len, buf_block); + + return type; +} + +/** + * rgblk_search - find a block in @old_state, change allocation + * state to @new_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 + * @new_state: GFS2_BLKST_XXX the after-allocation block state + * + * 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. + * + * Returns: the block number allocated + */ + +static uint32_t rgblk_search(struct gfs2_rgrpd *rgd, uint32_t goal, + unsigned char old_state, unsigned char new_state) +{ + struct gfs2_bitmap *bi = NULL; + uint32_t length = rgd->rd_ri.ri_length; + uint32_t blk = 0; + unsigned int buf, x; + + /* Find bitmap block that contains bits for goal block */ + for (buf = 0; buf < length; buf++) { + bi = rgd->rd_bits + buf; + if (goal < (bi->bi_start + bi->bi_len) * GFS2_NBBY) + break; + } + + gfs2_assert(rgd->rd_sbd, buf < length,); + + /* Convert scope of "goal" from rgrp-wide to within found bit block */ + goal -= bi->bi_start * GFS2_NBBY; + + /* Search (up to entire) bitmap in this rgrp for allocatable block. + "x <= length", instead of "x < length", because we typically start + the search in the middle of a bit block, but if we can't find an + allocatable block anywhere else, we want to be able wrap around and + search in the first part of our first-searched bit block. */ + for (x = 0; x <= length; x++) { + if (bi->bi_clone) + blk = gfs2_bitfit(rgd, + bi->bi_clone + bi->bi_offset, + bi->bi_len, goal, old_state); + else + blk = gfs2_bitfit(rgd, + bi->bi_bh->b_data + bi->bi_offset, + bi->bi_len, goal, old_state); + if (blk != BFITNOENT) + break; + + /* Try next bitmap block (wrap back to rgrp header if at end) */ + buf = (buf + 1) % length; + bi = rgd->rd_bits + buf; + goal = 0; + } + + if (gfs2_assert_withdraw(rgd->rd_sbd, x <= length)) + blk = 0; + + gfs2_trans_add_bh(rgd->rd_gl, bi->bi_bh); + gfs2_setbit(rgd, + bi->bi_bh->b_data + bi->bi_offset, + bi->bi_len, blk, new_state); + if (bi->bi_clone) + gfs2_setbit(rgd, + bi->bi_clone + bi->bi_offset, + bi->bi_len, blk, new_state); + + return bi->bi_start * GFS2_NBBY + blk; +} + +/** + * rgblk_free - Change alloc state of given block(s) + * @sdp: the filesystem + * @bstart: the start of a run of blocks to free + * @blen: the length of the block run (all must lie within ONE RG!) + * @new_state: GFS2_BLKST_XXX the after-allocation block state + * + * Returns: Resource group containing the block(s) + */ + +static struct gfs2_rgrpd *rgblk_free(struct gfs2_sbd *sdp, uint64_t bstart, + uint32_t blen, unsigned char new_state) +{ + struct gfs2_rgrpd *rgd; + struct gfs2_bitmap *bi = NULL; + uint32_t length, rgrp_blk, buf_blk; + unsigned int buf; + + rgd = gfs2_blk2rgrpd(sdp, bstart); + if (!rgd) { + if (gfs2_consist(sdp)) + fs_err(sdp, "block = %"PRIu64"\n", bstart); + return NULL; + } + + length = rgd->rd_ri.ri_length; + + rgrp_blk = bstart - rgd->rd_ri.ri_data0; + + while (blen--) { + for (buf = 0; buf < length; buf++) { + bi = rgd->rd_bits + buf; + if (rgrp_blk < (bi->bi_start + bi->bi_len) * GFS2_NBBY) + break; + } + + gfs2_assert(rgd->rd_sbd, buf < length,); + + buf_blk = rgrp_blk - bi->bi_start * GFS2_NBBY; + rgrp_blk++; + + if (!bi->bi_clone) { + bi->bi_clone = kmalloc(bi->bi_bh->b_size, + GFP_KERNEL | __GFP_NOFAIL); + memcpy(bi->bi_clone + bi->bi_offset, + bi->bi_bh->b_data + bi->bi_offset, + bi->bi_len); + } + gfs2_trans_add_bh(rgd->rd_gl, bi->bi_bh); + gfs2_setbit(rgd, + bi->bi_bh->b_data + bi->bi_offset, + bi->bi_len, buf_blk, new_state); + } + + return rgd; +} + +/** + * gfs2_alloc_data - Allocate a data block + * @ip: the inode to allocate the data block for + * + * Returns: the allocated block + */ + +uint64_t gfs2_alloc_data(struct gfs2_inode *ip) +{ + struct gfs2_sbd *sdp = ip->i_sbd; + struct gfs2_alloc *al = ip->i_alloc; + struct gfs2_rgrpd *rgd = al->al_rgd; + uint32_t goal, blk; + uint64_t block; + + if (rgrp_contains_block(&rgd->rd_ri, ip->i_di.di_goal_data)) + goal = ip->i_di.di_goal_data - rgd->rd_ri.ri_data0; + else + goal = rgd->rd_last_alloc_data; + + blk = rgblk_search(rgd, goal, + GFS2_BLKST_FREE, GFS2_BLKST_USED); + rgd->rd_last_alloc_data = blk; + + block = rgd->rd_ri.ri_data0 + blk; + ip->i_di.di_goal_data = block; + + gfs2_assert_withdraw(sdp, rgd->rd_rg.rg_free); + rgd->rd_rg.rg_free--; + + gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh); + gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data); + + al->al_alloced++; + + gfs2_statfs_change(sdp, 0, -1, 0); + gfs2_quota_change(ip, +1, ip->i_di.di_uid, ip->i_di.di_gid); + + spin_lock(&sdp->sd_rindex_spin); + rgd->rd_free_clone--; + spin_unlock(&sdp->sd_rindex_spin); + + return block; +} + +/** + * gfs2_alloc_meta - Allocate a metadata block + * @ip: the inode to allocate the metadata block for + * + * Returns: the allocated block + */ + +uint64_t gfs2_alloc_meta(struct gfs2_inode *ip) +{ + struct gfs2_sbd *sdp = ip->i_sbd; + struct gfs2_alloc *al = ip->i_alloc; + struct gfs2_rgrpd *rgd = al->al_rgd; + uint32_t goal, blk; + uint64_t block; + + if (rgrp_contains_block(&rgd->rd_ri, ip->i_di.di_goal_meta)) + goal = ip->i_di.di_goal_meta - rgd->rd_ri.ri_data0; + else + goal = rgd->rd_last_alloc_meta; + + blk = rgblk_search(rgd, goal, + GFS2_BLKST_FREE, GFS2_BLKST_USED); + rgd->rd_last_alloc_meta = blk; + + block = rgd->rd_ri.ri_data0 + blk; + ip->i_di.di_goal_meta = block; + + gfs2_assert_withdraw(sdp, rgd->rd_rg.rg_free); + rgd->rd_rg.rg_free--; + + gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh); + gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data); + + al->al_alloced++; + + gfs2_statfs_change(sdp, 0, -1, 0); + gfs2_quota_change(ip, +1, ip->i_di.di_uid, ip->i_di.di_gid); + gfs2_trans_add_unrevoke(sdp, block); + + spin_lock(&sdp->sd_rindex_spin); + rgd->rd_free_clone--; + spin_unlock(&sdp->sd_rindex_spin); + + return block; +} + +/** + * gfs2_alloc_di - Allocate a dinode + * @dip: the directory that the inode is going in + * + * Returns: the block allocated + */ + +uint64_t gfs2_alloc_di(struct gfs2_inode *dip) +{ + struct gfs2_sbd *sdp = dip->i_sbd; + struct gfs2_alloc *al = dip->i_alloc; + struct gfs2_rgrpd *rgd = al->al_rgd; + uint32_t blk; + uint64_t block; + + blk = rgblk_search(rgd, rgd->rd_last_alloc_meta, + GFS2_BLKST_FREE, GFS2_BLKST_DINODE); + + rgd->rd_last_alloc_meta = blk; + + block = rgd->rd_ri.ri_data0 + blk; + + gfs2_assert_withdraw(sdp, rgd->rd_rg.rg_free); + rgd->rd_rg.rg_free--; + rgd->rd_rg.rg_dinodes++; + + gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh); + gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data); + + al->al_alloced++; + + gfs2_statfs_change(sdp, 0, -1, +1); + gfs2_trans_add_unrevoke(sdp, block); + + spin_lock(&sdp->sd_rindex_spin); + rgd->rd_free_clone--; + spin_unlock(&sdp->sd_rindex_spin); + + return block; +} + +/** + * gfs2_free_data - free a contiguous run of data block(s) + * @ip: the inode these blocks are being freed from + * @bstart: first block of a run of contiguous blocks + * @blen: the length of the block run + * + */ + +void gfs2_free_data(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen) +{ + struct gfs2_sbd *sdp = ip->i_sbd; + struct gfs2_rgrpd *rgd; + + rgd = rgblk_free(sdp, bstart, blen, GFS2_BLKST_FREE); + if (!rgd) + return; + + rgd->rd_rg.rg_free += blen; + + gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh); + gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data); + + gfs2_trans_add_rg(rgd); + + gfs2_statfs_change(sdp, 0, +blen, 0); + gfs2_quota_change(ip, -(int64_t)blen, + ip->i_di.di_uid, ip->i_di.di_gid); +} + +/** + * gfs2_free_meta - free a contiguous run of data block(s) + * @ip: the inode these blocks are being freed from + * @bstart: first block of a run of contiguous blocks + * @blen: the length of the block run + * + */ + +void gfs2_free_meta(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen) +{ + struct gfs2_sbd *sdp = ip->i_sbd; + struct gfs2_rgrpd *rgd; + + rgd = rgblk_free(sdp, bstart, blen, GFS2_BLKST_FREE); + if (!rgd) + return; + + rgd->rd_rg.rg_free += blen; + + gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh); + gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data); + + gfs2_trans_add_rg(rgd); + + gfs2_statfs_change(sdp, 0, +blen, 0); + gfs2_quota_change(ip, -(int64_t)blen, + ip->i_di.di_uid, ip->i_di.di_gid); + gfs2_meta_wipe(ip, bstart, blen); +} + +void gfs2_free_uninit_di(struct gfs2_rgrpd *rgd, uint64_t blkno) +{ + struct gfs2_sbd *sdp = rgd->rd_sbd; + struct gfs2_rgrpd *tmp_rgd; + + tmp_rgd = rgblk_free(sdp, blkno, 1, GFS2_BLKST_FREE); + if (!tmp_rgd) + return; + gfs2_assert_withdraw(sdp, rgd == tmp_rgd); + + if (!rgd->rd_rg.rg_dinodes) + gfs2_consist_rgrpd(rgd); + rgd->rd_rg.rg_dinodes--; + rgd->rd_rg.rg_free++; + + gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh); + gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data); + + gfs2_statfs_change(sdp, 0, +1, -1); + gfs2_trans_add_rg(rgd); +} + +/** + * gfs2_free_uninit_di - free a dinode block + * @rgd: the resource group that contains the dinode + * @ip: the inode + * + */ + +void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip) +{ + gfs2_free_uninit_di(rgd, ip->i_num.no_addr); + gfs2_quota_change(ip, -1, ip->i_di.di_uid, ip->i_di.di_gid); + gfs2_meta_wipe(ip, ip->i_num.no_addr, 1); +} + +/** + * gfs2_rlist_add - add a RG to a list of RGs + * @sdp: the filesystem + * @rlist: the list of resource groups + * @block: the block + * + * Figure out what RG a block belongs to and add that RG to the list + * + * FIXME: Don't use NOFAIL + * + */ + +void gfs2_rlist_add(struct gfs2_sbd *sdp, struct gfs2_rgrp_list *rlist, + uint64_t block) +{ + struct gfs2_rgrpd *rgd; + struct gfs2_rgrpd **tmp; + unsigned int new_space; + unsigned int x; + + if (gfs2_assert_warn(sdp, !rlist->rl_ghs)) + return; + + rgd = gfs2_blk2rgrpd(sdp, block); + if (!rgd) { + if (gfs2_consist(sdp)) + fs_err(sdp, "block = %"PRIu64"\n", block); + return; + } + + for (x = 0; x < rlist->rl_rgrps; x++) + if (rlist->rl_rgd[x] == rgd) + return; + + if (rlist->rl_rgrps == rlist->rl_space) { + new_space = rlist->rl_space + 10; + + tmp = kcalloc(new_space, sizeof(struct gfs2_rgrpd *), + GFP_KERNEL | __GFP_NOFAIL); + + if (rlist->rl_rgd) { + memcpy(tmp, rlist->rl_rgd, + rlist->rl_space * sizeof(struct gfs2_rgrpd *)); + kfree(rlist->rl_rgd); + } + + rlist->rl_space = new_space; + rlist->rl_rgd = tmp; + } + + rlist->rl_rgd[rlist->rl_rgrps++] = rgd; +} + +/** + * gfs2_rlist_alloc - all RGs have been added to the rlist, now allocate + * and initialize an array of glock holders for them + * @rlist: the list of resource groups + * @state: the lock state to acquire the RG lock in + * @flags: the modifier flags for the holder structures + * + * FIXME: Don't use NOFAIL + * + */ + +void gfs2_rlist_alloc(struct gfs2_rgrp_list *rlist, unsigned int state, + int flags) +{ + unsigned int x; + + rlist->rl_ghs = kcalloc(rlist->rl_rgrps, sizeof(struct gfs2_holder), + GFP_KERNEL | __GFP_NOFAIL); + for (x = 0; x < rlist->rl_rgrps; x++) + gfs2_holder_init(rlist->rl_rgd[x]->rd_gl, + state, flags, + &rlist->rl_ghs[x]); +} + +/** + * gfs2_rlist_free - free a resource group list + * @list: the list of resource groups + * + */ + +void gfs2_rlist_free(struct gfs2_rgrp_list *rlist) +{ + unsigned int x; + + kfree(rlist->rl_rgd); + + if (rlist->rl_ghs) { + for (x = 0; x < rlist->rl_rgrps; x++) + gfs2_holder_uninit(&rlist->rl_ghs[x]); + kfree(rlist->rl_ghs); + } +} + --- a/fs/gfs2/rgrp.h 1970-01-01 07:30:00.000000000 +0730 +++ b/fs/gfs2/rgrp.h 2005-09-01 17:36:55.479090544 +0800 @@ -0,0 +1,62 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. + * + * This copyrighted material is made available to anyone wishing to use, + * modify, copy, or redistribute it subject to the terms and conditions + * of the GNU General Public License v.2. + */ + +#ifndef __RGRP_DOT_H__ +#define __RGRP_DOT_H__ + +void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd); + +struct gfs2_rgrpd *gfs2_blk2rgrpd(struct gfs2_sbd *sdp, uint64_t blk); +struct gfs2_rgrpd *gfs2_rgrpd_get_first(struct gfs2_sbd *sdp); +struct gfs2_rgrpd *gfs2_rgrpd_get_next(struct gfs2_rgrpd *rgd); + +void gfs2_clear_rgrpd(struct gfs2_sbd *sdp); +int gfs2_rindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ri_gh); + +int gfs2_rgrp_bh_get(struct gfs2_rgrpd *rgd); +void gfs2_rgrp_bh_hold(struct gfs2_rgrpd *rgd); +void gfs2_rgrp_bh_put(struct gfs2_rgrpd *rgd); + +void gfs2_rgrp_repolish_clones(struct gfs2_rgrpd *rgd); + +struct gfs2_alloc *gfs2_alloc_get(struct gfs2_inode *ip); +void gfs2_alloc_put(struct gfs2_inode *ip); + +int gfs2_inplace_reserve_i(struct gfs2_inode *ip, + char *file, unsigned int line); +#define gfs2_inplace_reserve(ip) \ +gfs2_inplace_reserve_i((ip), __FILE__, __LINE__) + +void gfs2_inplace_release(struct gfs2_inode *ip); + +unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, uint64_t block); + +uint64_t gfs2_alloc_data(struct gfs2_inode *ip); +uint64_t gfs2_alloc_meta(struct gfs2_inode *ip); +uint64_t gfs2_alloc_di(struct gfs2_inode *ip); + +void gfs2_free_data(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen); +void gfs2_free_meta(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen); +void gfs2_free_uninit_di(struct gfs2_rgrpd *rgd, uint64_t blkno); +void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip); + +struct gfs2_rgrp_list { + unsigned int rl_rgrps; + unsigned int rl_space; + struct gfs2_rgrpd **rl_rgd; + struct gfs2_holder *rl_ghs; +}; + +void gfs2_rlist_add(struct gfs2_sbd *sdp, struct gfs2_rgrp_list *rlist, + uint64_t block); +void gfs2_rlist_alloc(struct gfs2_rgrp_list *rlist, unsigned int state, + int flags); +void gfs2_rlist_free(struct gfs2_rgrp_list *rlist); + +#endif /* __RGRP_DOT_H__ */ --- a/fs/gfs2/bits.c 1970-01-01 07:30:00.000000000 +0730 +++ b/fs/gfs2/bits.c 2005-09-01 17:36:55.149140704 +0800 @@ -0,0 +1,179 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. + * + * This copyrighted material is made available to anyone wishing to use, + * modify, copy, or redistribute it subject to the terms and conditions + * of the GNU General Public License v.2. + */ + +/* + * These routines are used by the resource group routines (rgrp.c) + * to keep track of block allocation. Each block is represented by two + * bits. One bit indicates whether or not the block is used. (1=used, + * 0=free) The other bit indicates whether or not the block contains a + * dinode or not. (1=dinode, 0=not-dinode) So, each byte represents + * GFS2_NBBY (i.e. 4) blocks. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/smp_lock.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <asm/semaphore.h> + +#include "gfs2.h" +#include "bits.h" + +static const char valid_change[16] = { + /* current */ + /* n */ 0, 1, 0, 1, + /* e */ 1, 0, 0, 0, + /* w */ 0, 0, 0, 0, + 1, 0, 0, 0 +}; + +/** + * gfs2_setbit - Set a bit in the bitmaps + * @buffer: the buffer that holds the bitmaps + * @buflen: the length (in bytes) of the buffer + * @block: the block to set + * @new_state: the new state of the block + * + */ + +void gfs2_setbit(struct gfs2_rgrpd *rgd, unsigned char *buffer, + unsigned int buflen, uint32_t block, unsigned char new_state) +{ + unsigned char *byte, *end, cur_state; + unsigned int bit; + + byte = buffer + (block / GFS2_NBBY); + bit = (block % GFS2_NBBY) * GFS2_BIT_SIZE; + end = buffer + buflen; + + gfs2_assert(rgd->rd_sbd, byte < end,); + + cur_state = (*byte >> bit) & GFS2_BIT_MASK; + + if (valid_change[new_state * 4 + cur_state]) { + *byte ^= cur_state << bit; + *byte |= new_state << bit; + } else + gfs2_consist_rgrpd(rgd); +} + +/** + * gfs2_testbit - test a bit in the bitmaps + * @buffer: the buffer that holds the bitmaps + * @buflen: the length (in bytes) of the buffer + * @block: the block to read + * + */ + +unsigned char gfs2_testbit(struct gfs2_rgrpd *rgd, unsigned char *buffer, + unsigned int buflen, uint32_t block) +{ + unsigned char *byte, *end, cur_state; + unsigned int bit; + + byte = buffer + (block / GFS2_NBBY); + bit = (block % GFS2_NBBY) * GFS2_BIT_SIZE; + end = buffer + buflen; + + gfs2_assert(rgd->rd_sbd, byte < end,); + + cur_state = (*byte >> bit) & GFS2_BIT_MASK; + + return cur_state; +} + +/** + * gfs2_bitfit - Search an rgrp's bitmap buffer to find a bit-pair representing + * a block in a given allocation state. + * @buffer: the buffer that holds the bitmaps + * @buflen: the length (in bytes) of the buffer + * @goal: start search at this block's bit-pair (within @buffer) + * @old_state: GFS2_BLKST_XXX the state of the block we're looking for; + * bit 0 = alloc(1)/free(0), bit 1 = meta(1)/data(0) + * + * Scope of @goal and returned block number is only within this bitmap buffer, + * not entire rgrp or filesystem. @buffer will be offset from the actual + * beginning of a bitmap block buffer, skipping any header structures. + * + * Return: the block number (bitmap buffer scope) that was found + */ + +uint32_t gfs2_bitfit(struct gfs2_rgrpd *rgd, unsigned char *buffer, + unsigned int buflen, uint32_t goal, + unsigned char old_state) +{ + unsigned char *byte, *end, alloc; + uint32_t blk = goal; + unsigned int bit; + + byte = buffer + (goal / GFS2_NBBY); + bit = (goal % GFS2_NBBY) * GFS2_BIT_SIZE; + end = buffer + buflen; + alloc = (old_state & 1) ? 0 : 0x55; + + while (byte < end) { + if ((*byte & 0x55) == alloc) { + blk += (8 - bit) >> 1; + + bit = 0; + byte++; + + continue; + } + + if (((*byte >> bit) & GFS2_BIT_MASK) == old_state) + return blk; + + bit += GFS2_BIT_SIZE; + if (bit >= 8) { + bit = 0; + byte++; + } + + blk++; + } + + return BFITNOENT; +} + +/** + * gfs2_bitcount - count the number of bits in a certain state + * @buffer: the buffer that holds the bitmaps + * @buflen: the length (in bytes) of the buffer + * @state: the state of the block we're looking for + * + * Returns: The number of bits + */ + +uint32_t gfs2_bitcount(struct gfs2_rgrpd *rgd, unsigned char *buffer, + unsigned int buflen, unsigned char state) +{ + unsigned char *byte = buffer; + unsigned char *end = buffer + buflen; + unsigned char state1 = state << 2; + unsigned char state2 = state << 4; + unsigned char state3 = state << 6; + uint32_t count = 0; + + for (; byte < end; byte++) { + if (((*byte) & 0x03) == state) + count++; + if (((*byte) & 0x0C) == state1) + count++; + if (((*byte) & 0x30) == state2) + count++; + if (((*byte) & 0xC0) == state3) + count++; + } + + return count; +} + --- a/fs/gfs2/bits.h 1970-01-01 07:30:00.000000000 +0730 +++ b/fs/gfs2/bits.h 2005-09-01 17:36:55.149140704 +0800 @@ -0,0 +1,28 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. + * + * This copyrighted material is made available to anyone wishing to use, + * modify, copy, or redistribute it subject to the terms and conditions + * of the GNU General Public License v.2. + */ + +#ifndef __BITS_DOT_H__ +#define __BITS_DOT_H__ + +#define BFITNOENT 0xFFFFFFFF + +void gfs2_setbit(struct gfs2_rgrpd *rgd, + unsigned char *buffer, unsigned int buflen, + uint32_t block, unsigned char new_state); +unsigned char gfs2_testbit(struct gfs2_rgrpd *rgd, + unsigned char *buffer, unsigned int buflen, + uint32_t block); +uint32_t gfs2_bitfit(struct gfs2_rgrpd *rgd, + unsigned char *buffer, unsigned int buflen, + uint32_t goal, unsigned char old_state); +uint32_t gfs2_bitcount(struct gfs2_rgrpd *rgd, + unsigned char *buffer, unsigned int buflen, + unsigned char state); + +#endif /* __BITS_DOT_H__ */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/