forked from Minki/linux
zram: get rid of lockdep warning
Lockdep complains about recursive deadlock of zram->init_lock. [1] made it false positive because we can't request IO to zram before setting disksize. Anyway, we should shut lockdep up to avoid many reporting from user. [1] : zram: force disksize setting before using zram Acked-by: Jerome Marchand <jmarchan@redhat.com> Acked-by: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Minchan Kim
Greg Kroah-Hartman
parent
152bce6bdd
commit
8b3cc3edb7
@ -61,22 +61,22 @@ static void zram_stat64_inc(struct zram *zram, u64 *v)
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zram_stat64_add(zram, v, 1);
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}
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static int zram_test_flag(struct zram *zram, u32 index,
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static int zram_test_flag(struct zram_meta *meta, u32 index,
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enum zram_pageflags flag)
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{
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return zram->table[index].flags & BIT(flag);
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return meta->table[index].flags & BIT(flag);
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}
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static void zram_set_flag(struct zram *zram, u32 index,
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static void zram_set_flag(struct zram_meta *meta, u32 index,
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enum zram_pageflags flag)
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{
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zram->table[index].flags |= BIT(flag);
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meta->table[index].flags |= BIT(flag);
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}
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static void zram_clear_flag(struct zram *zram, u32 index,
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static void zram_clear_flag(struct zram_meta *meta, u32 index,
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enum zram_pageflags flag)
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{
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zram->table[index].flags &= ~BIT(flag);
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meta->table[index].flags &= ~BIT(flag);
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}
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static int page_zero_filled(void *ptr)
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@ -96,16 +96,17 @@ static int page_zero_filled(void *ptr)
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static void zram_free_page(struct zram *zram, size_t index)
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{
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unsigned long handle = zram->table[index].handle;
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u16 size = zram->table[index].size;
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struct zram_meta *meta = zram->meta;
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unsigned long handle = meta->table[index].handle;
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u16 size = meta->table[index].size;
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if (unlikely(!handle)) {
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/*
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* No memory is allocated for zero filled pages.
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* Simply clear zero page flag.
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*/
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if (zram_test_flag(zram, index, ZRAM_ZERO)) {
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zram_clear_flag(zram, index, ZRAM_ZERO);
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if (zram_test_flag(meta, index, ZRAM_ZERO)) {
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zram_clear_flag(meta, index, ZRAM_ZERO);
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zram->stats.pages_zero--;
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}
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return;
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@ -114,17 +115,17 @@ static void zram_free_page(struct zram *zram, size_t index)
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if (unlikely(size > max_zpage_size))
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zram->stats.bad_compress--;
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zs_free(zram->mem_pool, handle);
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zs_free(meta->mem_pool, handle);
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if (size <= PAGE_SIZE / 2)
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zram->stats.good_compress--;
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zram_stat64_sub(zram, &zram->stats.compr_size,
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zram->table[index].size);
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meta->table[index].size);
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zram->stats.pages_stored--;
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zram->table[index].handle = 0;
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zram->table[index].size = 0;
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meta->table[index].handle = 0;
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meta->table[index].size = 0;
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}
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static void handle_zero_page(struct bio_vec *bvec)
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@ -149,20 +150,21 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index)
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int ret = LZO_E_OK;
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size_t clen = PAGE_SIZE;
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unsigned char *cmem;
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unsigned long handle = zram->table[index].handle;
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struct zram_meta *meta = zram->meta;
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unsigned long handle = meta->table[index].handle;
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if (!handle || zram_test_flag(zram, index, ZRAM_ZERO)) {
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if (!handle || zram_test_flag(meta, index, ZRAM_ZERO)) {
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memset(mem, 0, PAGE_SIZE);
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return 0;
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}
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cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
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if (zram->table[index].size == PAGE_SIZE)
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cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO);
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if (meta->table[index].size == PAGE_SIZE)
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memcpy(mem, cmem, PAGE_SIZE);
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else
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ret = lzo1x_decompress_safe(cmem, zram->table[index].size,
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ret = lzo1x_decompress_safe(cmem, meta->table[index].size,
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mem, &clen);
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zs_unmap_object(zram->mem_pool, handle);
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zs_unmap_object(meta->mem_pool, handle);
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/* Should NEVER happen. Return bio error if it does. */
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if (unlikely(ret != LZO_E_OK)) {
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@ -180,11 +182,11 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
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int ret;
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struct page *page;
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unsigned char *user_mem, *uncmem = NULL;
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struct zram_meta *meta = zram->meta;
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page = bvec->bv_page;
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if (unlikely(!zram->table[index].handle) ||
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zram_test_flag(zram, index, ZRAM_ZERO)) {
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if (unlikely(!meta->table[index].handle) ||
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zram_test_flag(meta, index, ZRAM_ZERO)) {
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handle_zero_page(bvec);
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return 0;
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}
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@ -232,9 +234,10 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
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unsigned long handle;
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struct page *page;
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unsigned char *user_mem, *cmem, *src, *uncmem = NULL;
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struct zram_meta *meta = zram->meta;
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page = bvec->bv_page;
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src = zram->compress_buffer;
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src = meta->compress_buffer;
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if (is_partial_io(bvec)) {
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/*
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@ -256,8 +259,8 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
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* System overwrites unused sectors. Free memory associated
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* with this sector now.
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*/
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if (zram->table[index].handle ||
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zram_test_flag(zram, index, ZRAM_ZERO))
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if (meta->table[index].handle ||
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zram_test_flag(meta, index, ZRAM_ZERO))
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zram_free_page(zram, index);
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user_mem = kmap_atomic(page);
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@ -276,13 +279,13 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
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if (is_partial_io(bvec))
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kfree(uncmem);
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zram->stats.pages_zero++;
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zram_set_flag(zram, index, ZRAM_ZERO);
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zram_set_flag(meta, index, ZRAM_ZERO);
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ret = 0;
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goto out;
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}
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ret = lzo1x_1_compress(uncmem, PAGE_SIZE, src, &clen,
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zram->compress_workmem);
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meta->compress_workmem);
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if (!is_partial_io(bvec)) {
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kunmap_atomic(user_mem);
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@ -303,14 +306,14 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
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src = uncmem;
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}
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handle = zs_malloc(zram->mem_pool, clen);
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handle = zs_malloc(meta->mem_pool, clen);
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if (!handle) {
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pr_info("Error allocating memory for compressed "
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"page: %u, size=%zu\n", index, clen);
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ret = -ENOMEM;
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goto out;
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}
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cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_WO);
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cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_WO);
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if ((clen == PAGE_SIZE) && !is_partial_io(bvec))
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src = kmap_atomic(page);
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@ -318,10 +321,10 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
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if ((clen == PAGE_SIZE) && !is_partial_io(bvec))
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kunmap_atomic(src);
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zs_unmap_object(zram->mem_pool, handle);
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zs_unmap_object(meta->mem_pool, handle);
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zram->table[index].handle = handle;
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zram->table[index].size = clen;
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meta->table[index].handle = handle;
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meta->table[index].size = clen;
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/* Update stats */
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zram_stat64_add(zram, &zram->stats.compr_size, clen);
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@ -464,34 +467,25 @@ error:
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void __zram_reset_device(struct zram *zram)
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{
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size_t index;
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struct zram_meta *meta;
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if (!zram->init_done)
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return;
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meta = zram->meta;
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zram->init_done = 0;
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/* Free various per-device buffers */
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kfree(zram->compress_workmem);
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free_pages((unsigned long)zram->compress_buffer, 1);
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zram->compress_workmem = NULL;
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zram->compress_buffer = NULL;
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/* Free all pages that are still in this zram device */
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for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) {
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unsigned long handle = zram->table[index].handle;
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unsigned long handle = meta->table[index].handle;
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if (!handle)
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continue;
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zs_free(zram->mem_pool, handle);
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zs_free(meta->mem_pool, handle);
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}
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vfree(zram->table);
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zram->table = NULL;
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zs_destroy_pool(zram->mem_pool);
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zram->mem_pool = NULL;
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zram_meta_free(zram->meta);
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zram->meta = NULL;
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/* Reset stats */
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memset(&zram->stats, 0, sizeof(zram->stats));
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@ -506,12 +500,65 @@ void zram_reset_device(struct zram *zram)
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up_write(&zram->init_lock);
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}
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/* zram->init_lock should be held */
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int zram_init_device(struct zram *zram)
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void zram_meta_free(struct zram_meta *meta)
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{
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int ret;
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size_t num_pages;
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zs_destroy_pool(meta->mem_pool);
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kfree(meta->compress_workmem);
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free_pages((unsigned long)meta->compress_buffer, 1);
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vfree(meta->table);
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kfree(meta);
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}
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struct zram_meta *zram_meta_alloc(u64 disksize)
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{
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size_t num_pages;
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struct zram_meta *meta = kmalloc(sizeof(*meta), GFP_KERNEL);
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if (!meta)
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goto out;
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meta->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
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if (!meta->compress_workmem) {
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pr_err("Error allocating compressor working memory!\n");
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goto free_meta;
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}
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meta->compress_buffer =
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(void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);
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if (!meta->compress_buffer) {
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pr_err("Error allocating compressor buffer space\n");
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goto free_workmem;
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}
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num_pages = disksize >> PAGE_SHIFT;
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meta->table = vzalloc(num_pages * sizeof(*meta->table));
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if (!meta->table) {
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pr_err("Error allocating zram address table\n");
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goto free_buffer;
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}
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meta->mem_pool = zs_create_pool(GFP_NOIO | __GFP_HIGHMEM);
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if (!meta->mem_pool) {
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pr_err("Error creating memory pool\n");
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goto free_table;
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}
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return meta;
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free_table:
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vfree(meta->table);
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free_buffer:
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free_pages((unsigned long)meta->compress_buffer, 1);
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free_workmem:
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kfree(meta->compress_workmem);
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free_meta:
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kfree(meta);
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meta = NULL;
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out:
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return meta;
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}
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void zram_init_device(struct zram *zram, struct zram_meta *meta)
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{
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if (zram->disksize > 2 * (totalram_pages << PAGE_SHIFT)) {
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pr_info(
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"There is little point creating a zram of greater than "
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@ -526,51 +573,13 @@ int zram_init_device(struct zram *zram)
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);
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}
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zram->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
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if (!zram->compress_workmem) {
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pr_err("Error allocating compressor working memory!\n");
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ret = -ENOMEM;
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goto fail_no_table;
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}
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zram->compress_buffer =
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(void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);
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if (!zram->compress_buffer) {
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pr_err("Error allocating compressor buffer space\n");
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ret = -ENOMEM;
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goto fail_no_table;
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}
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num_pages = zram->disksize >> PAGE_SHIFT;
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zram->table = vzalloc(num_pages * sizeof(*zram->table));
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if (!zram->table) {
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pr_err("Error allocating zram address table\n");
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ret = -ENOMEM;
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goto fail_no_table;
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}
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/* zram devices sort of resembles non-rotational disks */
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queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue);
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zram->mem_pool = zs_create_pool(GFP_NOIO | __GFP_HIGHMEM);
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if (!zram->mem_pool) {
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pr_err("Error creating memory pool\n");
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ret = -ENOMEM;
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goto fail;
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}
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zram->meta = meta;
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zram->init_done = 1;
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pr_debug("Initialization done!\n");
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return 0;
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fail_no_table:
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/* To prevent accessing table entries during cleanup */
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zram->disksize = 0;
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fail:
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__zram_reset_device(zram);
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pr_err("Initialization failed: err=%d\n", ret);
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return ret;
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}
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static void zram_slot_free_notify(struct block_device *bdev,
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@ -83,11 +83,15 @@ struct zram_stats {
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u32 bad_compress; /* % of pages with compression ratio>=75% */
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};
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struct zram {
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struct zs_pool *mem_pool;
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struct zram_meta {
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void *compress_workmem;
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void *compress_buffer;
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struct table *table;
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struct zs_pool *mem_pool;
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};
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struct zram {
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struct zram_meta *meta;
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spinlock_t stat64_lock; /* protect 64-bit stats */
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struct rw_semaphore lock; /* protect compression buffers and table
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* against concurrent read and writes */
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@ -111,7 +115,9 @@ unsigned int zram_get_num_devices(void);
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extern struct attribute_group zram_disk_attr_group;
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#endif
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extern int zram_init_device(struct zram *zram);
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extern void zram_reset_device(struct zram *zram);
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extern struct zram_meta *zram_meta_alloc(u64 disksize);
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extern void zram_meta_free(struct zram_meta *meta);
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extern void zram_init_device(struct zram *zram, struct zram_meta *meta);
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#endif
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@ -56,22 +56,26 @@ static ssize_t disksize_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t len)
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{
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u64 disksize;
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struct zram_meta *meta;
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struct zram *zram = dev_to_zram(dev);
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disksize = memparse(buf, NULL);
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if (!disksize)
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return -EINVAL;
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disksize = PAGE_ALIGN(disksize);
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meta = zram_meta_alloc(disksize);
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down_write(&zram->init_lock);
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if (zram->init_done) {
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up_write(&zram->init_lock);
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zram_meta_free(meta);
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pr_info("Cannot change disksize for initialized device\n");
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return -EBUSY;
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}
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zram->disksize = PAGE_ALIGN(disksize);
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zram->disksize = disksize;
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set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
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zram_init_device(zram);
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zram_init_device(zram, meta);
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up_write(&zram->init_lock);
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return len;
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@ -182,9 +186,10 @@ static ssize_t mem_used_total_show(struct device *dev,
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{
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u64 val = 0;
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struct zram *zram = dev_to_zram(dev);
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struct zram_meta *meta = zram->meta;
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if (zram->init_done)
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val = zs_get_total_size_bytes(zram->mem_pool);
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val = zs_get_total_size_bytes(meta->mem_pool);
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return sprintf(buf, "%llu\n", val);
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}
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