X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fgfs2%2Frgrp.c;h=bdad0dffc6b4b841a505c03ef4992b011e6f75e6;hb=383f01fbf4a701b73f5e35ea805ed1700b4b4db9;hp=4291375cecc6e5f4700acbba719a7d1ead1ed6cf;hpb=9b8c81d1de49943ec69d157234b8981008c30d31;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 4291375..bdad0df 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -14,6 +14,7 @@ #include #include #include +#include #include "gfs2.h" #include "incore.h" @@ -33,6 +34,16 @@ #define BFITNOENT ((u32)~0) #define NO_BLOCK ((u64)~0) +#if BITS_PER_LONG == 32 +#define LBITMASK (0x55555555UL) +#define LBITSKIP55 (0x55555555UL) +#define LBITSKIP00 (0x00000000UL) +#else +#define LBITMASK (0x5555555555555555UL) +#define LBITSKIP55 (0x5555555555555555UL) +#define LBITSKIP00 (0x0000000000000000UL) +#endif + /* * These routines are used by the resource group routines (rgrp.c) * to keep track of block allocation. Each block is represented by two @@ -138,45 +149,63 @@ static inline unsigned char gfs2_testbit(struct gfs2_rgrpd *rgd, static u32 gfs2_bitfit(const u8 *buffer, unsigned int buflen, u32 goal, u8 old_state) { - const u8 *byte; - u32 blk = goal; - unsigned int bit, bitlong; - const unsigned long *plong; -#if BITS_PER_LONG == 32 - const unsigned long plong55 = 0x55555555; -#else - const unsigned long plong55 = 0x5555555555555555; -#endif - - byte = buffer + (goal / GFS2_NBBY); - plong = (const unsigned long *)(buffer + (goal / GFS2_NBBY)); - bit = (goal % GFS2_NBBY) * GFS2_BIT_SIZE; - bitlong = bit; - - while (byte < buffer + buflen) { - - if (bitlong == 0 && old_state == 0 && *plong == plong55) { - plong++; - byte += sizeof(unsigned long); - blk += sizeof(unsigned long) * GFS2_NBBY; - continue; + const u8 *byte, *start, *end; + int bit, startbit; + u32 g1, g2, misaligned; + unsigned long *plong; + unsigned long lskipval; + + lskipval = (old_state & GFS2_BLKST_USED) ? LBITSKIP00 : LBITSKIP55; + g1 = (goal / GFS2_NBBY); + start = buffer + g1; + byte = start; + end = buffer + buflen; + g2 = ALIGN(g1, sizeof(unsigned long)); + plong = (unsigned long *)(buffer + g2); + startbit = bit = (goal % GFS2_NBBY) * GFS2_BIT_SIZE; + misaligned = g2 - g1; + if (!misaligned) + goto ulong_aligned; +/* parse the bitmap a byte at a time */ +misaligned: + while (byte < end) { + if (((*byte >> bit) & GFS2_BIT_MASK) == old_state) { + return goal + + (((byte - start) * GFS2_NBBY) + + ((bit - startbit) >> 1)); } - if (((*byte >> bit) & GFS2_BIT_MASK) == old_state) - return blk; bit += GFS2_BIT_SIZE; - if (bit >= 8) { + if (bit >= GFS2_NBBY * GFS2_BIT_SIZE) { bit = 0; byte++; + misaligned--; + if (!misaligned) { + plong = (unsigned long *)byte; + goto ulong_aligned; + } } - bitlong += GFS2_BIT_SIZE; - if (bitlong >= sizeof(unsigned long) * 8) { - bitlong = 0; - plong++; - } - - blk++; } + return BFITNOENT; +/* parse the bitmap a unsigned long at a time */ +ulong_aligned: + /* Stop at "end - 1" or else prefetch can go past the end and segfault. + We could "if" it but we'd lose some of the performance gained. + This way will only slow down searching the very last 4/8 bytes + depending on architecture. I've experimented with several ways + of writing this section such as using an else before the goto + but this one seems to be the fastest. */ + while ((unsigned char *)plong < end - sizeof(unsigned long)) { + prefetch(plong + 1); + if (((*plong) & LBITMASK) != lskipval) + break; + plong++; + } + if ((unsigned char *)plong < end) { + byte = (const u8 *)plong; + misaligned += sizeof(unsigned long) - 1; + goto misaligned; + } return BFITNOENT; } @@ -342,11 +371,6 @@ static void clear_rgrpdi(struct gfs2_sbd *sdp) 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; @@ -477,7 +501,7 @@ u64 gfs2_ri_total(struct gfs2_sbd *sdp) for (rgrps = 0;; rgrps++) { loff_t pos = rgrps * sizeof(struct gfs2_rindex); - if (pos + sizeof(struct gfs2_rindex) >= ip->i_di.di_size) + if (pos + sizeof(struct gfs2_rindex) >= ip->i_disksize) break; error = gfs2_internal_read(ip, &ra_state, buf, &pos, sizeof(struct gfs2_rindex)); @@ -566,7 +590,7 @@ static int gfs2_ri_update(struct gfs2_inode *ip) struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); struct inode *inode = &ip->i_inode; struct file_ra_state ra_state; - u64 rgrp_count = ip->i_di.di_size; + u64 rgrp_count = ip->i_disksize; int error; if (do_div(rgrp_count, sizeof(struct gfs2_rindex))) { @@ -610,7 +634,7 @@ static int gfs2_ri_update_special(struct gfs2_inode *ip) for (sdp->sd_rgrps = 0;; sdp->sd_rgrps++) { /* Ignore partials */ if ((sdp->sd_rgrps + 1) * sizeof(struct gfs2_rindex) > - ip->i_di.di_size) + ip->i_disksize) break; error = read_rindex_entry(ip, &ra_state); if (error) { @@ -916,107 +940,30 @@ static struct inode *try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked) } /** - * 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, - u64 rglast) -{ - struct gfs2_rgrpd *rgd; - - spin_lock(&sdp->sd_rindex_spin); - - if (rglast) { - list_for_each_entry(rgd, &sdp->sd_rindex_recent_list, rd_recent) { - if (rgrp_contains_block(rgd, rglast)) - goto out; - } - } - rgd = NULL; - if (!list_empty(&sdp->sd_rindex_recent_list)) - 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) +static struct gfs2_rgrpd *recent_rgrp_next(struct gfs2_rgrpd *cur_rgd) { 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; - } + head = &sdp->sd_rindex_mru_list; + if (unlikely(cur_rgd->rd_list_mru.next == head)) { + spin_unlock(&sdp->sd_rindex_spin); + return NULL; } - - rgd = NULL; - if (!list_empty(head)) - rgd = list_entry(head->next, struct gfs2_rgrpd, rd_recent); - -out: + rgd = list_entry(cur_rgd->rd_list_mru.next, struct gfs2_rgrpd, rd_list_mru); 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 * @@ -1083,9 +1030,7 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) int loops = 0; int error, rg_locked; - /* Try recently successful rgrps */ - - rgd = recent_rgrp_first(sdp, ip->i_goal); + rgd = gfs2_blk2rgrpd(sdp, ip->i_goal); while (rgd) { rg_locked = 0; @@ -1107,11 +1052,9 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) gfs2_glock_dq_uninit(&al->al_rgd_gh); if (inode) return inode; - rgd = recent_rgrp_next(rgd, 1); - break; - + /* fall through */ case GLR_TRYFAILED: - rgd = recent_rgrp_next(rgd, 0); + rgd = recent_rgrp_next(rgd); break; default: @@ -1170,7 +1113,9 @@ static struct inode *get_local_rgrp(struct gfs2_inode *ip, u64 *last_unlinked) out: if (begin) { - recent_rgrp_add(rgd); + spin_lock(&sdp->sd_rindex_spin); + list_move(&rgd->rd_list_mru, &sdp->sd_rindex_mru_list); + spin_unlock(&sdp->sd_rindex_spin); rgd = gfs2_rgrpd_get_next(rgd); if (!rgd) rgd = gfs2_rgrpd_get_first(sdp); @@ -1466,7 +1411,7 @@ u64 gfs2_alloc_block(struct gfs2_inode *ip, unsigned int *n) al->al_alloced += *n; - gfs2_statfs_change(sdp, 0, -*n, 0); + gfs2_statfs_change(sdp, 0, -(s64)*n, 0); gfs2_quota_change(ip, *n, ip->i_inode.i_uid, ip->i_inode.i_gid); spin_lock(&sdp->sd_rindex_spin);