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From: Namjae Jeon <namjae.jeon@samsung.com>
To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc: gregkh@linuxfoundation.org, valdis.kletnieks@vt.edu, hch@lst.de,
	sj1557.seo@samsung.com, linkinjeon@gmail.com,
	pali.rohar@gmail.com, arnd@arndb.de,
	Namjae Jeon <namjae.jeon@samsung.com>
Subject: [PATCH v10 07/14] exfat: add bitmap operations
Date: Wed, 15 Jan 2020 17:24:40 +0900
Message-ID: <20200115082447.19520-8-namjae.jeon@samsung.com> (raw)
In-Reply-To: <20200115082447.19520-1-namjae.jeon@samsung.com>

This adds the implementation of bitmap operations for exfat.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
---
 fs/exfat/balloc.c | 282 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 282 insertions(+)
 create mode 100644 fs/exfat/balloc.c

diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c
new file mode 100644
index 000000000000..b568f5efc984
--- /dev/null
+++ b/fs/exfat/balloc.c
@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include <linux/buffer_head.h>
+
+#include "exfat_raw.h"
+#include "exfat_fs.h"
+
+static const unsigned char free_bit[] = {
+	0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2,/*  0 ~  19*/
+	0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3,/* 20 ~  39*/
+	0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/* 40 ~  59*/
+	0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4,/* 60 ~  79*/
+	0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2,/* 80 ~  99*/
+	0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3,/*100 ~ 119*/
+	0, 1, 0, 2, 0, 1, 0, 7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/*120 ~ 139*/
+	0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5,/*140 ~ 159*/
+	0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2,/*160 ~ 179*/
+	0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3,/*180 ~ 199*/
+	0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/*200 ~ 219*/
+	0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4,/*220 ~ 239*/
+	0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0                /*240 ~ 254*/
+};
+
+static const unsigned char used_bit[] = {
+	0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3,/*  0 ~  19*/
+	2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 1, 2, 2, 3, 2, 3, 3, 4,/* 20 ~  39*/
+	2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5,/* 40 ~  59*/
+	4, 5, 5, 6, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,/* 60 ~  79*/
+	2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4,/* 80 ~  99*/
+	3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6,/*100 ~ 119*/
+	4, 5, 5, 6, 5, 6, 6, 7, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4,/*120 ~ 139*/
+	3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,/*140 ~ 159*/
+	2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5,/*160 ~ 179*/
+	4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 2, 3, 3, 4, 3, 4, 4, 5,/*180 ~ 199*/
+	3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6,/*200 ~ 219*/
+	5, 6, 6, 7, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,/*220 ~ 239*/
+	4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8             /*240 ~ 255*/
+};
+
+/*
+ *  Allocation Bitmap Management Functions
+ */
+static int exfat_allocate_bitmap(struct super_block *sb,
+		struct exfat_dentry *ep)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	long long map_size;
+	unsigned int i, need_map_size;
+	sector_t sector;
+
+	sbi->map_clu = le32_to_cpu(ep->dentry.bitmap.start_clu);
+	map_size = le64_to_cpu(ep->dentry.bitmap.size);
+	need_map_size = ((EXFAT_DATA_CLUSTER_COUNT(sbi) - 1) / BITS_PER_BYTE)
+		+ 1;
+	if (need_map_size != map_size) {
+		exfat_msg(sb, KERN_ERR,
+				"bogus allocation bitmap size(need : %u, cur : %lld)",
+				need_map_size, map_size);
+		/*
+		 * Only allowed when bogus allocation
+		 * bitmap size is large
+		 */
+		if (need_map_size > map_size)
+			return -EIO;
+	}
+	sbi->map_sectors = ((need_map_size - 1) >>
+			(sb->s_blocksize_bits)) + 1;
+	sbi->vol_amap = kmalloc_array(sbi->map_sectors,
+				sizeof(struct buffer_head *), GFP_KERNEL);
+	if (!sbi->vol_amap)
+		return -ENOMEM;
+
+	sector = exfat_cluster_to_sector(sbi, sbi->map_clu);
+	for (i = 0; i < sbi->map_sectors; i++) {
+		sbi->vol_amap[i] = sb_bread(sb, sector + i);
+		if (!sbi->vol_amap[i]) {
+			/* release all buffers and free vol_amap */
+			int j = 0;
+
+			while (j < i)
+				brelse(sbi->vol_amap[j++]);
+
+			kfree(sbi->vol_amap);
+			sbi->vol_amap = NULL;
+			return -EIO;
+		}
+	}
+
+	sbi->pbr_bh = NULL;
+	return 0;
+}
+
+int exfat_load_bitmap(struct super_block *sb)
+{
+	unsigned int i, type;
+	struct exfat_chain clu;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+	exfat_chain_set(&clu, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
+	while (clu.dir != EXFAT_EOF_CLUSTER) {
+		for (i = 0; i < sbi->dentries_per_clu; i++) {
+			struct exfat_dentry *ep;
+			struct buffer_head *bh;
+
+			ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
+			if (!ep)
+				return -EIO;
+
+			type = exfat_get_entry_type(ep);
+			if (type == TYPE_UNUSED)
+				break;
+			if (type != TYPE_BITMAP)
+				continue;
+			if (ep->dentry.bitmap.flags == 0x0) {
+				int err;
+
+				err = exfat_allocate_bitmap(sb, ep);
+				brelse(bh);
+				return err;
+			}
+			brelse(bh);
+		}
+
+		if (exfat_get_next_cluster(sb, &clu.dir))
+			return -EIO;
+	}
+
+	return -EINVAL;
+}
+
+void exfat_free_bitmap(struct super_block *sb)
+{
+	int i;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+	brelse(sbi->pbr_bh);
+
+	for (i = 0; i < sbi->map_sectors; i++)
+		__brelse(sbi->vol_amap[i]);
+
+	kfree(sbi->vol_amap);
+	sbi->vol_amap = NULL;
+}
+
+/*
+ * If the value of "clu" is 0, it means cluster 2 which is the first cluster of
+ * the cluster heap.
+ */
+int exfat_set_bitmap(struct inode *inode, unsigned int clu)
+{
+	int i, b;
+	unsigned int ent_idx;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+	WARN_ON(clu < EXFAT_FIRST_CLUSTER);
+	ent_idx = CLUSTER_TO_BITMAP_ENT(clu);
+	i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);
+	b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);
+
+	set_bit_le(b, sbi->vol_amap[i]->b_data);
+	exfat_update_bh(sb, sbi->vol_amap[i], IS_DIRSYNC(inode));
+	return 0;
+}
+
+/*
+ * If the value of "clu" is 0, it means cluster 2 which is the first cluster of
+ * the cluster heap.
+ */
+void exfat_clear_bitmap(struct inode *inode, unsigned int clu)
+{
+	int i, b;
+	unsigned int ent_idx;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	struct exfat_mount_options *opts = &sbi->options;
+
+	WARN_ON(clu < EXFAT_FIRST_CLUSTER);
+	ent_idx = CLUSTER_TO_BITMAP_ENT(clu);
+	i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);
+	b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);
+
+	clear_bit_le(b, sbi->vol_amap[i]->b_data);
+	exfat_update_bh(sb, sbi->vol_amap[i], IS_DIRSYNC(inode));
+
+	if (opts->discard) {
+		int ret_discard;
+
+		ret_discard = sb_issue_discard(sb,
+			exfat_cluster_to_sector(sbi, clu +
+						EXFAT_RESERVED_CLUSTERS),
+			(1 << sbi->sect_per_clus_bits), GFP_NOFS, 0);
+
+		if (ret_discard == -EOPNOTSUPP) {
+			exfat_msg(sb, KERN_ERR,
+				"discard not supported by device, disabling");
+			opts->discard = 0;
+		}
+	}
+}
+
+/*
+ * If the value of "clu" is 0, it means cluster 2 which is the first cluster of
+ * the cluster heap.
+ */
+unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu)
+{
+	unsigned int i, map_i, map_b, ent_idx;
+	unsigned int clu_base, clu_free;
+	unsigned char k, clu_mask;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+	WARN_ON(clu < EXFAT_FIRST_CLUSTER);
+	ent_idx = CLUSTER_TO_BITMAP_ENT(clu);
+	clu_base = BITMAP_ENT_TO_CLUSTER(ent_idx & ~(BITS_PER_BYTE_MASK));
+	clu_mask = IGNORED_BITS_REMAINED(clu, clu_base);
+
+	map_i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);
+	map_b = BITMAP_OFFSET_BYTE_IN_SECTOR(sb, ent_idx);
+
+	for (i = EXFAT_FIRST_CLUSTER; i < sbi->num_clusters;
+	     i += BITS_PER_BYTE) {
+		k = *(sbi->vol_amap[map_i]->b_data + map_b);
+		if (clu_mask > 0) {
+			k |= clu_mask;
+			clu_mask = 0;
+		}
+		if (k < 0xFF) {
+			clu_free = clu_base + free_bit[k];
+			if (clu_free < sbi->num_clusters)
+				return clu_free;
+		}
+		clu_base += BITS_PER_BYTE;
+
+		if (++map_b >= sb->s_blocksize ||
+		    clu_base >= sbi->num_clusters) {
+			if (++map_i >= sbi->map_sectors) {
+				clu_base = EXFAT_FIRST_CLUSTER;
+				map_i = 0;
+			}
+			map_b = 0;
+		}
+	}
+
+	return EXFAT_EOF_CLUSTER;
+}
+
+int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	unsigned int count = 0;
+	unsigned int i, map_i = 0, map_b = 0;
+	unsigned int total_clus = EXFAT_DATA_CLUSTER_COUNT(sbi);
+	unsigned int last_mask = total_clus & BITS_PER_BYTE_MASK;
+	unsigned char clu_bits;
+	const unsigned char last_bit_mask[] = {0, 0b00000001, 0b00000011,
+		0b00000111, 0b00001111, 0b00011111, 0b00111111, 0b01111111};
+
+	total_clus &= ~last_mask;
+	for (i = 0; i < total_clus; i += BITS_PER_BYTE) {
+		clu_bits = *(sbi->vol_amap[map_i]->b_data + map_b);
+		count += used_bit[clu_bits];
+		if (++map_b >= (unsigned int)sb->s_blocksize) {
+			map_i++;
+			map_b = 0;
+		}
+	}
+
+	if (last_mask) {
+		clu_bits = *(sbi->vol_amap[map_i]->b_data + map_b);
+		clu_bits &= last_bit_mask[last_mask];
+		count += used_bit[clu_bits];
+	}
+
+	*ret_count = count;
+	return 0;
+}
-- 
2.17.1


  parent reply index

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20200115082818epcas1p4892a99345626188afd111ee263132458@epcas1p4.samsung.com>
2020-01-15  8:24 ` [PATCH v10 00/14] add the latest exfat driver Namjae Jeon
     [not found]   ` <CGME20200115082819epcas1p3303009557f8bf670b47991530f380ef7@epcas1p3.samsung.com>
2020-01-15  8:24     ` [PATCH v10 01/14] exfat: add in-memory and on-disk structures and headers Namjae Jeon
     [not found]   ` <CGME20200115082819epcas1p3825d5bed592a8378ad26254d07d59b18@epcas1p3.samsung.com>
2020-01-15  8:24     ` [PATCH v10 02/14] exfat: add super block operations Namjae Jeon
     [not found]   ` <CGME20200115082820epcas1p34ebebebaf610fd61c4e9882fca8ddbd5@epcas1p3.samsung.com>
2020-01-15  8:24     ` [PATCH v10 03/14] exfat: add inode operations Namjae Jeon
2020-01-15 10:25       ` Arnd Bergmann
2020-01-15 13:39         ` Namjae Jeon
2020-01-17  9:25       ` Pali Rohár
2020-01-17 11:17       ` Pali Rohár
     [not found]   ` <CGME20200115082821epcas1p3db1f70cf53185c40934c3a754c65e648@epcas1p3.samsung.com>
2020-01-15  8:24     ` [PATCH v10 04/14] exfat: add directory operations Namjae Jeon
2020-01-17 11:13       ` Pali Rohár
     [not found]   ` <CGME20200115082821epcas1p4d76d8668dfac70ae3e3889d4ccb6c3ee@epcas1p4.samsung.com>
2020-01-15  8:24     ` [PATCH v10 05/14] exfat: add file operations Namjae Jeon
2020-01-15  9:56       ` Arnd Bergmann
2020-01-15 13:07         ` Namjae Jeon
2020-01-17  9:18       ` Pali Rohár
2020-01-17 12:12         ` Namjae Jeon
     [not found]   ` <CGME20200115082822epcas1p37aca37dad0aa9159d7eddde01edfeec2@epcas1p3.samsung.com>
2020-01-15  8:24     ` [PATCH v10 06/14] exfat: add fat entry operations Namjae Jeon
     [not found]   ` <CGME20200115082822epcas1p384d080724d8bb0a8cd4c3e3015a0895c@epcas1p3.samsung.com>
2020-01-15  8:24     ` Namjae Jeon [this message]
     [not found]   ` <CGME20200115082823epcas1p27ec5ff6d384f148d826529f573173b04@epcas1p2.samsung.com>
2020-01-15  8:24     ` [PATCH v10 08/14] exfat: add exfat cache Namjae Jeon
     [not found]   ` <CGME20200115082824epcas1p4eb45d088c2f88149acb94563c4a9b276@epcas1p4.samsung.com>
2020-01-15  8:24     ` [PATCH v10 09/14] exfat: add misc operations Namjae Jeon
2020-01-15 10:10       ` Arnd Bergmann
2020-01-15 13:30         ` Namjae Jeon
2020-01-15 13:38           ` Pali Rohár
2020-01-15 13:50             ` Arnd Bergmann
2020-01-15 14:24               ` Pali Rohár
2020-01-15 15:03                 ` Arnd Bergmann
2020-01-15 15:39                   ` Pali Rohár
2020-01-15 15:52                     ` Arnd Bergmann
2020-01-16 10:19                       ` Pali Rohár
2020-01-16 10:23                         ` Christoph Hellwig
2020-01-16 16:00                           ` Pali Rohár
2020-01-17  2:59                       ` Namjae Jeon
2020-01-17 10:13                         ` Arnd Bergmann
2020-01-17 12:13                           ` Namjae Jeon
     [not found]   ` <CGME20200115082824epcas1p23a0fa255a5833c6dcd2479b384f37740@epcas1p2.samsung.com>
2020-01-15  8:24     ` [PATCH v10 10/14] exfat: add nls operations Namjae Jeon
     [not found]   ` <CGME20200115082825epcas1p1f22ddca6dbf5d70e65d3b0e3c25c3a59@epcas1p1.samsung.com>
2020-01-15  8:24     ` [PATCH v10 11/14] exfat: add Kconfig and Makefile Namjae Jeon
2020-01-15  9:39       ` Pali Rohár
2020-01-17  4:22         ` Namjae Jeon
2020-01-17  9:12           ` Pali Rohár
2020-01-17 11:59             ` Namjae Jeon
     [not found]   ` <CGME20200115082825epcas1p4a0d63d53d8737a84fe8867bc1e63811e@epcas1p4.samsung.com>
2020-01-15  8:24     ` [PATCH v10 12/14] exfat: add exfat in fs/Kconfig and fs/Makefile Namjae Jeon
     [not found]   ` <CGME20200115082826epcas1p117191a39ecccaef5a9b5cbe77b05c5a5@epcas1p1.samsung.com>
2020-01-15  8:24     ` [PATCH v10 13/14] MAINTAINERS: add exfat filesystem Namjae Jeon
     [not found]   ` <CGME20200115082826epcas1p3475ce2b4d03234dc96ced428be582eb3@epcas1p3.samsung.com>
2020-01-15  8:24     ` [PATCH v10 14/14] staging: exfat: make staging/exfat and fs/exfat mutually exclusive Namjae Jeon
2020-01-15  8:56       ` Greg KH
2020-01-15 13:06         ` Namjae Jeon
2020-01-15  9:47   ` [PATCH v10 00/14] add the latest exfat driver Pali Rohár
2020-01-15 13:05     ` Namjae Jeon
2020-01-16 10:51     ` Christoph Hellwig
2020-01-16 11:32       ` Pali Rohár
2020-01-16 13:01       ` Greg KH

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