Commit 5c2d7285 authored by Hyeongseok Kim's avatar Hyeongseok Kim Committed by Namjae Jeon
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exfat: introduce bitmap_lock for cluster bitmap access 



s_lock which is for protecting concurrent access of file operations is
too huge for cluster bitmap protection, so introduce a new bitmap_lock
to narrow the lock range if only need to access cluster bitmap.

Signed-off-by: default avatarHyeongseok Kim <hyeongseok@gmail.com>
Acked-by: default avatarSungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: default avatarNamjae Jeon <namjae.jeon@samsung.com>
parent 77edfc6e

fs/exfat/exfat_fs.h

+1 −0
Original line number Diff line number Diff line
@@ -238,6 +238,7 @@ struct exfat_sb_info { 
	unsigned int used_clusters; /* number of used clusters */



	struct mutex s_lock; /* superblock lock */

	struct mutex bitmap_lock; /* bitmap lock */

	struct exfat_mount_options options;

	struct nls_table *nls_io; /* Charset used for input and display */

	struct ratelimit_state ratelimit;

fs/exfat/fatent.c

+29 −8
Original line number Diff line number Diff line
@@ -151,13 +151,14 @@ int exfat_chain_cont_cluster(struct super_block *sb, unsigned int chain, 
	return 0;

}



int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain)

/* This function must be called with bitmap_lock held */

static int __exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain)

{

	unsigned int num_clusters = 0;

	unsigned int clu;

	struct super_block *sb = inode->i_sb;

	struct exfat_sb_info *sbi = EXFAT_SB(sb);

	int cur_cmap_i, next_cmap_i;

	unsigned int num_clusters = 0;

	unsigned int clu;



	/* invalid cluster number */

	if (p_chain->dir == EXFAT_FREE_CLUSTER ||
@@ -230,6 +231,17 @@ int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain) 
	return 0;

}



int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain)

{

	int ret = 0;



	mutex_lock(&EXFAT_SB(inode->i_sb)->bitmap_lock);

	ret = __exfat_free_cluster(inode, p_chain);

	mutex_unlock(&EXFAT_SB(inode->i_sb)->bitmap_lock);



	return ret;

}



int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain,

		unsigned int *ret_clu)

{
@@ -328,6 +340,8 @@ int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc, 
	if (num_alloc > total_cnt - sbi->used_clusters)

		return -ENOSPC;



	mutex_lock(&sbi->bitmap_lock);



	hint_clu = p_chain->dir;

	/* find new cluster */

	if (hint_clu == EXFAT_EOF_CLUSTER) {
@@ -338,8 +352,10 @@ int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc, 
		}



		hint_clu = exfat_find_free_bitmap(sb, sbi->clu_srch_ptr);

		if (hint_clu == EXFAT_EOF_CLUSTER)

			return -ENOSPC;

		if (hint_clu == EXFAT_EOF_CLUSTER) {

			ret = -ENOSPC;

			goto unlock;

		}

	}



	/* check cluster validation */
@@ -349,8 +365,10 @@ int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc, 
		hint_clu = EXFAT_FIRST_CLUSTER;

		if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {

			if (exfat_chain_cont_cluster(sb, p_chain->dir,

					num_clusters))

				return -EIO;

					num_clusters)) {

				ret = -EIO;

				goto unlock;

			}

			p_chain->flags = ALLOC_FAT_CHAIN;

		}

	}
@@ -400,6 +418,7 @@ int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc, 
			sbi->used_clusters += num_clusters;



			p_chain->size += num_clusters;

			mutex_unlock(&sbi->bitmap_lock);

			return 0;

		}
@@ -419,7 +438,9 @@ int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc, 
	}

free_cluster:

	if (num_clusters)

		exfat_free_cluster(inode, p_chain);

		__exfat_free_cluster(inode, p_chain);

unlock:

	mutex_unlock(&sbi->bitmap_lock);

	return ret;

}

fs/exfat/super.c

+1 −0
Original line number Diff line number Diff line
@@ -752,6 +752,7 @@ static int exfat_init_fs_context(struct fs_context *fc) 
		return -ENOMEM;



	mutex_init(&sbi->s_lock);

	mutex_init(&sbi->bitmap_lock);

	ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,

			DEFAULT_RATELIMIT_BURST);