Merge tag 'exfat-for-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat

Pull exfat update from Namjae Jeon:

 - simplify and remove some redundant directory entry code

 - optimize the size of exfat_entry_set_cache and its allocation policy

 - improve the performance for creating files and directories

* tag 'exfat-for-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat:
  exfat: reuse exfat_find_location() to simplify exfat_get_dentry_set()
  exfat: fix overflow in sector and cluster conversion
  exfat: remove i_size_write() from __exfat_truncate()
  exfat: remove argument 'size' from exfat_truncate()
  exfat: remove unnecessary arguments from exfat_find_dir_entry()
  exfat: remove unneeded codes from __exfat_rename()
  exfat: remove call ilog2() from exfat_readdir()
  exfat: replace magic numbers with Macros
  exfat: rename exfat_free_dentry_set() to exfat_put_dentry_set()
  exfat: move exfat_entry_set_cache from heap to stack
  exfat: support dynamic allocate bh for exfat_entry_set_cache
  exfat: reduce the size of exfat_entry_set_cache
  exfat: hint the empty entry which at the end of cluster chain
  exfat: simplify empty entry hint

fs/exfat/exfat_fs.h

@@ -9,6 +9,7 @@
 #include <linux/fs.h>
 #include <linux/ratelimit.h>
 #include <linux/nls.h>
+#include <linux/blkdev.h>
 
 #define EXFAT_ROOT_INO		1
 
@@ -41,6 +42,14 @@ enum {
 #define ES_2_ENTRIES		2
 #define ES_ALL_ENTRIES		0
 
+#define ES_IDX_FILE		0
+#define ES_IDX_STREAM		1
+#define ES_IDX_FIRST_FILENAME	2
+#define EXFAT_FILENAME_ENTRY_NUM(name_len) \
+	DIV_ROUND_UP(name_len, EXFAT_FILE_NAME_LEN)
+#define ES_IDX_LAST_FILENAME(name_len)	\
+	(ES_IDX_FIRST_FILENAME + EXFAT_FILENAME_ENTRY_NUM(name_len) - 1)
+
 #define DIR_DELETED		0xFFFF0321
 
 /* type values */
@@ -62,15 +71,11 @@ enum {
 #define TYPE_PADDING		0x0402
 #define TYPE_ACLTAB		0x0403
 #define TYPE_BENIGN_SEC		0x0800
-#define TYPE_ALL		0x0FFF
 
 #define MAX_CHARSET_SIZE	6 /* max size of multi-byte character */
 #define MAX_NAME_LENGTH		255 /* max len of file name excluding NULL */
 #define MAX_VFSNAME_BUF_SIZE	((MAX_NAME_LENGTH + 1) * MAX_CHARSET_SIZE)
 
-/* Enough size to hold 256 dentry (even 512 Byte sector) */
-#define DIR_CACHE_SIZE		(256*sizeof(struct exfat_dentry)/512+1)
-
 #define EXFAT_HINT_NONE		-1
 #define EXFAT_MIN_SUBDIR	2
 
@@ -95,11 +100,17 @@ enum {
 /*
  * helpers for block size to dentry size conversion.
  */
-#define EXFAT_B_TO_DEN_IDX(b, sbi)	\
-	((b) << ((sbi)->cluster_size_bits - DENTRY_SIZE_BITS))
 #define EXFAT_B_TO_DEN(b)		((b) >> DENTRY_SIZE_BITS)
 #define EXFAT_DEN_TO_B(b)		((b) << DENTRY_SIZE_BITS)
 
+/*
+ * helpers for cluster size to dentry size conversion.
+ */
+#define EXFAT_CLU_TO_DEN(clu, sbi)	\
+	((clu) << ((sbi)->cluster_size_bits - DENTRY_SIZE_BITS))
+#define EXFAT_DEN_TO_CLU(dentry, sbi)	\
+	((dentry) >> ((sbi)->cluster_size_bits - DENTRY_SIZE_BITS))
+
 /*
  * helpers for fat entry.
  */
@@ -125,6 +136,17 @@ enum {
 #define BITS_PER_BYTE_MASK	0x7
 #define IGNORED_BITS_REMAINED(clu, clu_base) ((1 << ((clu) - (clu_base))) - 1)
 
+#define ES_ENTRY_NUM(name_len)	(ES_IDX_LAST_FILENAME(name_len) + 1)
+/* 19 entries = 1 file entry + 1 stream entry + 17 filename entries */
+#define ES_MAX_ENTRY_NUM	ES_ENTRY_NUM(MAX_NAME_LENGTH)
+
+/*
+ * 19 entries x 32 bytes/entry = 608 bytes.
+ * The 608 bytes are in 3 sectors at most (even 512 Byte sector).
+ */
+#define DIR_CACHE_SIZE		\
+	(DIV_ROUND_UP(EXFAT_DEN_TO_B(ES_MAX_ENTRY_NUM), SECTOR_SIZE) + 1)
+
 struct exfat_dentry_namebuf {
 	char *lfn;
 	int lfnbuf_len; /* usually MAX_UNINAME_BUF_SIZE */
@@ -166,13 +188,16 @@ struct exfat_hint {
 
 struct exfat_entry_set_cache {
 	struct super_block *sb;
-	bool modified;
 	unsigned int start_off;
 	int num_bh;
-	struct buffer_head *bh[DIR_CACHE_SIZE];
+	struct buffer_head *__bh[DIR_CACHE_SIZE];
+	struct buffer_head **bh;
 	unsigned int num_entries;
+	bool modified;
 };
 
+#define IS_DYNAMIC_ES(es)	((es)->__bh != (es)->bh)
+
 struct exfat_dir_entry {
 	struct exfat_chain dir;
 	int entry;
@@ -375,7 +400,7 @@ static inline sector_t exfat_cluster_to_sector(struct exfat_sb_info *sbi,
 		sbi->data_start_sector;
 }
 
-static inline int exfat_sector_to_cluster(struct exfat_sb_info *sbi,
+static inline unsigned int exfat_sector_to_cluster(struct exfat_sb_info *sbi,
 		sector_t sec)
 {
 	return ((sec - sbi->data_start_sector) >> sbi->sect_per_clus_bits) +
@@ -423,8 +448,8 @@ int exfat_trim_fs(struct inode *inode, struct fstrim_range *range);
 
 /* file.c */
 extern const struct file_operations exfat_file_operations;
-int __exfat_truncate(struct inode *inode, loff_t new_size);
-void exfat_truncate(struct inode *inode, loff_t size);
+int __exfat_truncate(struct inode *inode);
+void exfat_truncate(struct inode *inode);
 int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		  struct iattr *attr);
 int exfat_getattr(struct user_namespace *mnt_userns, const struct path *path,
@@ -464,15 +489,16 @@ void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es);
 int exfat_calc_num_entries(struct exfat_uni_name *p_uniname);
 int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
 		struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
-		int num_entries, unsigned int type, struct exfat_hint *hint_opt);
+		struct exfat_hint *hint_opt);
 int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu);
 struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
 		struct exfat_chain *p_dir, int entry, struct buffer_head **bh);
 struct exfat_dentry *exfat_get_dentry_cached(struct exfat_entry_set_cache *es,
 		int num);
-struct exfat_entry_set_cache *exfat_get_dentry_set(struct super_block *sb,
-		struct exfat_chain *p_dir, int entry, unsigned int type);
-int exfat_free_dentry_set(struct exfat_entry_set_cache *es, int sync);
+int exfat_get_dentry_set(struct exfat_entry_set_cache *es,
+		struct super_block *sb, struct exfat_chain *p_dir, int entry,
+		unsigned int type);
+int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync);
 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir);
 
 /* inode.c */

fs/exfat/file.c

@@ -93,7 +93,7 @@ static int exfat_sanitize_mode(const struct exfat_sb_info *sbi,
 }
 
 /* resize the file length */
-int __exfat_truncate(struct inode *inode, loff_t new_size)
+int __exfat_truncate(struct inode *inode)
 {
 	unsigned int num_clusters_new, num_clusters_phys;
 	unsigned int last_clu = EXFAT_FREE_CLUSTER;
@@ -113,7 +113,7 @@ int __exfat_truncate(struct inode *inode, loff_t new_size)
 
 	exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);
 
-	if (new_size > 0) {
+	if (i_size_read(inode) > 0) {
 		/*
 		 * Truncate FAT chain num_clusters after the first cluster
 		 * num_clusters = min(new, phys);
@@ -143,8 +143,6 @@ int __exfat_truncate(struct inode *inode, loff_t new_size)
 		ei->start_clu = EXFAT_EOF_CLUSTER;
 	}
 
-	i_size_write(inode, new_size);
-
 	if (ei->type == TYPE_FILE)
 		ei->attr |= ATTR_ARCHIVE;
 
@@ -189,7 +187,7 @@ int __exfat_truncate(struct inode *inode, loff_t new_size)
 	return 0;
 }
 
-void exfat_truncate(struct inode *inode, loff_t size)
+void exfat_truncate(struct inode *inode)
 {
 	struct super_block *sb = inode->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
@@ -207,7 +205,7 @@ void exfat_truncate(struct inode *inode, loff_t size)
 		goto write_size;
 	}
 
-	err = __exfat_truncate(inode, i_size_read(inode));
+	err = __exfat_truncate(inode);
 	if (err)
 		goto write_size;
 
@@ -310,7 +308,7 @@ int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		 * __exfat_write_inode() is called from exfat_truncate(), inode
 		 * is already written by it, so mark_inode_dirty() is unneeded.
 		 */
-		exfat_truncate(inode, attr->ia_size);
+		exfat_truncate(inode);
 		up_write(&EXFAT_I(inode)->truncate_lock);
 	} else
 		mark_inode_dirty(inode);

fs/exfat/inode.c

@@ -21,7 +21,7 @@ int __exfat_write_inode(struct inode *inode, int sync)
 {
 	unsigned long long on_disk_size;
 	struct exfat_dentry *ep, *ep2;
-	struct exfat_entry_set_cache *es = NULL;
+	struct exfat_entry_set_cache es;
 	struct super_block *sb = inode->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct exfat_inode_info *ei = EXFAT_I(inode);
@@ -42,11 +42,10 @@ int __exfat_write_inode(struct inode *inode, int sync)
 	exfat_set_volume_dirty(sb);
 
 	/* get the directory entry of given file or directory */
-	es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry, ES_ALL_ENTRIES);
-	if (!es)
+	if (exfat_get_dentry_set(&es, sb, &(ei->dir), ei->entry, ES_ALL_ENTRIES))
 		return -EIO;
-	ep = exfat_get_dentry_cached(es, 0);
-	ep2 = exfat_get_dentry_cached(es, 1);
+	ep = exfat_get_dentry_cached(&es, ES_IDX_FILE);
+	ep2 = exfat_get_dentry_cached(&es, ES_IDX_STREAM);
 
 	ep->dentry.file.attr = cpu_to_le16(exfat_make_attr(inode));
 
@@ -83,8 +82,8 @@ int __exfat_write_inode(struct inode *inode, int sync)
 		ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER;
 	}
 
-	exfat_update_dir_chksum_with_entry_set(es);
-	return exfat_free_dentry_set(es, sync);
+	exfat_update_dir_chksum_with_entry_set(&es);
+	return exfat_put_dentry_set(&es, sync);
 }
 
 int exfat_write_inode(struct inode *inode, struct writeback_control *wbc)
@@ -358,7 +357,7 @@ static void exfat_write_failed(struct address_space *mapping, loff_t to)
 	if (to > i_size_read(inode)) {
 		truncate_pagecache(inode, i_size_read(inode));
 		inode->i_mtime = inode->i_ctime = current_time(inode);
-		exfat_truncate(inode, EXFAT_I(inode)->i_size_aligned);
+		exfat_truncate(inode);
 	}
 }
 
@@ -622,7 +621,7 @@ void exfat_evict_inode(struct inode *inode)
 	if (!inode->i_nlink) {
 		i_size_write(inode, 0);
 		mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
-		__exfat_truncate(inode, 0);
+		__exfat_truncate(inode);
 		mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
 	}
 

fs/exfat/namei.c

@@ -224,11 +224,18 @@ static int exfat_search_empty_slot(struct super_block *sb,
 
 	if (hint_femp->eidx != EXFAT_HINT_NONE) {
 		dentry = hint_femp->eidx;
-		if (num_entries <= hint_femp->count) {
-			hint_femp->eidx = EXFAT_HINT_NONE;
-			return dentry;
-		}
 
+		/*
+		 * If hint_femp->count is enough, it is needed to check if
+		 * there are actual empty entries.
+		 * Otherwise, and if "dentry + hint_famp->count" is also equal
+		 * to "p_dir->size * dentries_per_clu", it means ENOSPC.
+		 */
+		if (dentry + hint_femp->count == p_dir->size * dentries_per_clu &&
+		    num_entries > hint_femp->count)
+			return -ENOSPC;
+
+		hint_femp->eidx = EXFAT_HINT_NONE;
 		exfat_chain_dup(&clu, &hint_femp->cur);
 	} else {
 		exfat_chain_dup(&clu, p_dir);
@@ -293,6 +300,12 @@ static int exfat_search_empty_slot(struct super_block *sb,
 		}
 	}
 
+	hint_femp->eidx = p_dir->size * dentries_per_clu - num_empty;
+	hint_femp->count = num_empty;
+	if (num_empty == 0)
+		exfat_chain_set(&hint_femp->cur, EXFAT_EOF_CLUSTER, 0,
+				clu.flags);
+
 	return -ENOSPC;
 }
 
@@ -369,15 +382,11 @@ static int exfat_find_empty_entry(struct inode *inode,
 			if (exfat_ent_set(sb, last_clu, clu.dir))
 				return -EIO;
 
-		if (hint_femp.eidx == EXFAT_HINT_NONE) {
-			/* the special case that new dentry
-			 * should be allocated from the start of new cluster
-			 */
-			hint_femp.eidx = EXFAT_B_TO_DEN_IDX(p_dir->size, sbi);
-			hint_femp.count = sbi->dentries_per_clu;
-
+		if (hint_femp.cur.dir == EXFAT_EOF_CLUSTER)
 			exfat_chain_set(&hint_femp.cur, clu.dir, 0, clu.flags);
-		}
+
+		hint_femp.count += sbi->dentries_per_clu;
+
 		hint_femp.cur.size++;
 		p_dir->size++;
 		size = EXFAT_CLU_TO_B(p_dir->size, sbi);
@@ -588,14 +597,14 @@ static int exfat_create(struct user_namespace *mnt_userns, struct inode *dir,
 static int exfat_find(struct inode *dir, struct qstr *qname,
 		struct exfat_dir_entry *info)
 {
-	int ret, dentry, num_entries, count;
+	int ret, dentry, count;
 	struct exfat_chain cdir;
 	struct exfat_uni_name uni_name;
 	struct super_block *sb = dir->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct exfat_inode_info *ei = EXFAT_I(dir);
 	struct exfat_dentry *ep, *ep2;
-	struct exfat_entry_set_cache *es;
+	struct exfat_entry_set_cache es;
 	/* for optimized dir & entry to prevent long traverse of cluster chain */
 	struct exfat_hint hint_opt;
 
@@ -607,10 +616,6 @@ static int exfat_find(struct inode *dir, struct qstr *qname,
 	if (ret)
 		return ret;
 
-	num_entries = exfat_calc_num_entries(&uni_name);
-	if (num_entries < 0)
-		return num_entries;
-
 	/* check the validation of hint_stat and initialize it if required */
 	if (ei->version != (inode_peek_iversion_raw(dir) & 0xffffffff)) {
 		ei->hint_stat.clu = cdir.dir;
@@ -620,9 +625,7 @@ static int exfat_find(struct inode *dir, struct qstr *qname,
 	}
 
 	/* search the file name for directories */
-	dentry = exfat_find_dir_entry(sb, ei, &cdir, &uni_name,
-			num_entries, TYPE_ALL, &hint_opt);
-
+	dentry = exfat_find_dir_entry(sb, ei, &cdir, &uni_name, &hint_opt);
 	if (dentry < 0)
 		return dentry; /* -error value */
 
@@ -635,11 +638,10 @@ static int exfat_find(struct inode *dir, struct qstr *qname,
 	if (cdir.flags & ALLOC_NO_FAT_CHAIN)
 		cdir.size -= dentry / sbi->dentries_per_clu;
 	dentry = hint_opt.eidx;
-	es = exfat_get_dentry_set(sb, &cdir, dentry, ES_2_ENTRIES);
-	if (!es)
+	if (exfat_get_dentry_set(&es, sb, &cdir, dentry, ES_2_ENTRIES))
 		return -EIO;
-	ep = exfat_get_dentry_cached(es, 0);
-	ep2 = exfat_get_dentry_cached(es, 1);
+	ep = exfat_get_dentry_cached(&es, ES_IDX_FILE);
+	ep2 = exfat_get_dentry_cached(&es, ES_IDX_STREAM);
 
 	info->type = exfat_get_entry_type(ep);
 	info->attr = le16_to_cpu(ep->dentry.file.attr);
@@ -668,7 +670,7 @@ static int exfat_find(struct inode *dir, struct qstr *qname,
 			     ep->dentry.file.access_time,
 			     ep->dentry.file.access_date,
 			     0);
-	exfat_free_dentry_set(es, false);
+	exfat_put_dentry_set(&es, false);
 
 	if (ei->start_clu == EXFAT_FREE_CLUSTER) {
 		exfat_fs_error(sb,
@@ -1167,7 +1169,7 @@ static int __exfat_rename(struct inode *old_parent_inode,
 	struct exfat_inode_info *new_ei = NULL;
 	unsigned int new_entry_type = TYPE_UNUSED;
 	int new_entry = 0;
-	struct buffer_head *old_bh, *new_bh = NULL;
+	struct buffer_head *new_bh = NULL;
 
 	/* check the validity of pointer parameters */
 	if (new_path == NULL || strlen(new_path) == 0)
@@ -1183,13 +1185,6 @@ static int __exfat_rename(struct inode *old_parent_inode,
 		EXFAT_I(old_parent_inode)->flags);
 	dentry = ei->entry;
 
-	ep = exfat_get_dentry(sb, &olddir, dentry, &old_bh);
-	if (!ep) {
-		ret = -EIO;
-		goto out;
-	}
-	brelse(old_bh);
-
 	/* check whether new dir is existing directory and empty */
 	if (new_inode) {
 		ret = -EIO;