From: Steven Whitehouse Date: Thu, 12 Dec 2013 17:29:32 +0000 (+0000) Subject: GFS2: Clean up quota slot allocation X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ee2411a8db49a21bc55dc124e1b434ba194c8903;p=linux-beck.git GFS2: Clean up quota slot allocation Quota slot allocation has historically used a vector of pages and a set of homegrown find/test/set/clear bit functions. Since the size of the bitmap is likely to be based on the default qc file size, thats a couple of pages at most. So we ought to be able to allocate that as a single chunk, with a vmalloc fallback, just in case of memory fragmentation. We are then able to use the kernel's own find/test/set/clear bit functions, rather than rolling our own. Signed-off-by: Steven Whitehouse Cc: Abhijith Das --- diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h index 59d99ec9d875..4b9aa5b6908c 100644 --- a/fs/gfs2/incore.h +++ b/fs/gfs2/incore.h @@ -733,8 +733,7 @@ struct gfs2_sbd { spinlock_t sd_trunc_lock; unsigned int sd_quota_slots; - unsigned int sd_quota_chunks; - unsigned char **sd_quota_bitmap; + unsigned long *sd_quota_bitmap; u64 sd_quota_sync_gen; diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c index 3287d9871508..79be67ab8603 100644 --- a/fs/gfs2/quota.c +++ b/fs/gfs2/quota.c @@ -315,50 +315,30 @@ static void qd_put(struct gfs2_quota_data *qd) static int slot_get(struct gfs2_quota_data *qd) { - struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd; - unsigned int c, o = 0, b; - unsigned char byte = 0; + struct gfs2_sbd *sdp = qd->qd_sbd; + unsigned int bit; + int error = 0; spin_lock(&qd_lock); + if (qd->qd_slot_count != 0) + goto out; - if (qd->qd_slot_count++) { - spin_unlock(&qd_lock); - return 0; + error = -ENOSPC; + bit = find_first_zero_bit(sdp->sd_quota_bitmap, sdp->sd_quota_slots); + if (bit < sdp->sd_quota_slots) { + set_bit(bit, sdp->sd_quota_bitmap); + qd->qd_slot = bit; +out: + qd->qd_slot_count++; } - - for (c = 0; c < sdp->sd_quota_chunks; c++) - for (o = 0; o < PAGE_SIZE; o++) { - byte = sdp->sd_quota_bitmap[c][o]; - if (byte != 0xFF) - goto found; - } - - goto fail; - -found: - for (b = 0; b < 8; b++) - if (!(byte & (1 << b))) - break; - qd->qd_slot = c * (8 * PAGE_SIZE) + o * 8 + b; - - if (qd->qd_slot >= sdp->sd_quota_slots) - goto fail; - - sdp->sd_quota_bitmap[c][o] |= 1 << b; - spin_unlock(&qd_lock); - return 0; - -fail: - qd->qd_slot_count--; - spin_unlock(&qd_lock); - return -ENOSPC; + return error; } static void slot_hold(struct gfs2_quota_data *qd) { - struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd; + struct gfs2_sbd *sdp = qd->qd_sbd; spin_lock(&qd_lock); gfs2_assert(sdp, qd->qd_slot_count); @@ -366,34 +346,14 @@ static void slot_hold(struct gfs2_quota_data *qd) spin_unlock(&qd_lock); } -static void gfs2_icbit_munge(struct gfs2_sbd *sdp, unsigned char **bitmap, - unsigned int bit, int new_value) -{ - unsigned int c, o, b = bit; - int old_value; - - c = b / (8 * PAGE_SIZE); - b %= 8 * PAGE_SIZE; - o = b / 8; - b %= 8; - - old_value = (bitmap[c][o] & (1 << b)); - gfs2_assert_withdraw(sdp, !old_value != !new_value); - - if (new_value) - bitmap[c][o] |= 1 << b; - else - bitmap[c][o] &= ~(1 << b); -} - static void slot_put(struct gfs2_quota_data *qd) { - struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd; + struct gfs2_sbd *sdp = qd->qd_sbd; spin_lock(&qd_lock); gfs2_assert(sdp, qd->qd_slot_count); if (!--qd->qd_slot_count) { - gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0); + BUG_ON(!test_and_clear_bit(qd->qd_slot, sdp->sd_quota_bitmap)); qd->qd_slot = -1; } spin_unlock(&qd_lock); @@ -1269,6 +1229,7 @@ int gfs2_quota_init(struct gfs2_sbd *sdp) unsigned int x, slot = 0; unsigned int found = 0; unsigned int hash; + unsigned int bm_size; u64 dblock; u32 extlen = 0; int error; @@ -1277,20 +1238,16 @@ int gfs2_quota_init(struct gfs2_sbd *sdp) return -EIO; sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block; - sdp->sd_quota_chunks = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * PAGE_SIZE); - + bm_size = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * sizeof(unsigned long)); + bm_size *= sizeof(unsigned long); error = -ENOMEM; - - sdp->sd_quota_bitmap = kcalloc(sdp->sd_quota_chunks, - sizeof(unsigned char *), GFP_NOFS); + sdp->sd_quota_bitmap = kmalloc(bm_size, GFP_NOFS|__GFP_NOWARN); + if (sdp->sd_quota_bitmap == NULL) + sdp->sd_quota_bitmap = __vmalloc(bm_size, GFP_NOFS, PAGE_KERNEL); if (!sdp->sd_quota_bitmap) return error; - for (x = 0; x < sdp->sd_quota_chunks; x++) { - sdp->sd_quota_bitmap[x] = kzalloc(PAGE_SIZE, GFP_NOFS); - if (!sdp->sd_quota_bitmap[x]) - goto fail; - } + memset(sdp->sd_quota_bitmap, 0, bm_size); for (x = 0; x < blocks; x++) { struct buffer_head *bh; @@ -1339,7 +1296,7 @@ int gfs2_quota_init(struct gfs2_sbd *sdp) qd->qd_slot_count = 1; spin_lock(&qd_lock); - gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1); + BUG_ON(test_and_set_bit(slot, sdp->sd_quota_bitmap)); list_add(&qd->qd_list, &sdp->sd_quota_list); atomic_inc(&sdp->sd_quota_count); spin_unlock(&qd_lock); @@ -1370,7 +1327,6 @@ void gfs2_quota_cleanup(struct gfs2_sbd *sdp) { struct list_head *head = &sdp->sd_quota_list; struct gfs2_quota_data *qd; - unsigned int x; spin_lock(&qd_lock); while (!list_empty(head)) { @@ -1401,9 +1357,11 @@ void gfs2_quota_cleanup(struct gfs2_sbd *sdp) gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count)); if (sdp->sd_quota_bitmap) { - for (x = 0; x < sdp->sd_quota_chunks; x++) - kfree(sdp->sd_quota_bitmap[x]); - kfree(sdp->sd_quota_bitmap); + if (is_vmalloc_addr(sdp->sd_quota_bitmap)) + vfree(sdp->sd_quota_bitmap); + else + kfree(sdp->sd_quota_bitmap); + sdp->sd_quota_bitmap = NULL; } }