diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h index 2dbed5f8ec26..090f25d1a418 100644 --- a/fs/exfat/exfat_fs.h +++ b/fs/exfat/exfat_fs.h @@ -10,6 +10,7 @@ #include #include #include +#include #include #define EXFAT_ROOT_INO 1 @@ -79,6 +80,10 @@ enum { #define EXFAT_HINT_NONE -1 #define EXFAT_MIN_SUBDIR 2 +#define EXFAT_BLK_RA_SIZE(sb) \ + (min_t(blkcnt_t, (sb)->s_bdi->ra_pages, (sb)->s_bdi->io_pages) \ + << (PAGE_SHIFT - (sb)->s_blocksize_bits)) + /* * helpers for cluster size to byte conversion. */ @@ -117,9 +122,9 @@ enum { #define FAT_ENT_SIZE (4) #define FAT_ENT_SIZE_BITS (2) #define FAT_ENT_OFFSET_SECTOR(sb, loc) (EXFAT_SB(sb)->FAT1_start_sector + \ - (((u64)loc << FAT_ENT_SIZE_BITS) >> sb->s_blocksize_bits)) + (((u64)(loc) << FAT_ENT_SIZE_BITS) >> sb->s_blocksize_bits)) #define FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc) \ - ((loc << FAT_ENT_SIZE_BITS) & (sb->s_blocksize - 1)) + (((loc) << FAT_ENT_SIZE_BITS) & (sb->s_blocksize - 1)) /* * helpers for bitmap. @@ -448,6 +453,8 @@ int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain, unsigned int *ret_clu); int exfat_count_num_clusters(struct super_block *sb, struct exfat_chain *p_chain, unsigned int *ret_count); +int exfat_blk_readahead(struct super_block *sb, sector_t sec, + sector_t *ra, blkcnt_t *ra_cnt, sector_t end); /* balloc.c */ int exfat_load_bitmap(struct super_block *sb); diff --git a/fs/exfat/fatent.c b/fs/exfat/fatent.c index f87576ca7032..9a4143f3fc0c 100644 --- a/fs/exfat/fatent.c +++ b/fs/exfat/fatent.c @@ -142,13 +142,50 @@ int exfat_ent_get(struct super_block *sb, unsigned int loc, return -EIO; } +int exfat_blk_readahead(struct super_block *sb, sector_t sec, + sector_t *ra, blkcnt_t *ra_cnt, sector_t end) +{ + struct blk_plug plug; + + if (sec < *ra) + return 0; + + *ra += *ra_cnt; + + /* No blocks left (or only the last block), skip readahead. */ + if (*ra >= end) + return 0; + + *ra_cnt = min(end - *ra + 1, EXFAT_BLK_RA_SIZE(sb)); + if (*ra_cnt == 0) { + /* Move 'ra' to the end to disable readahead. */ + *ra = end; + return 0; + } + + blk_start_plug(&plug); + for (unsigned int i = 0; i < *ra_cnt; i++) + sb_breadahead(sb, *ra + i); + blk_finish_plug(&plug); + return 0; +} + int exfat_chain_cont_cluster(struct super_block *sb, unsigned int chain, unsigned int len) { + sector_t sec, end, ra; + blkcnt_t ra_cnt = 0; + if (!len) return 0; + ra = FAT_ENT_OFFSET_SECTOR(sb, chain); + end = FAT_ENT_OFFSET_SECTOR(sb, chain + len - 1); + while (len > 1) { + sec = FAT_ENT_OFFSET_SECTOR(sb, chain); + exfat_blk_readahead(sb, sec, &ra, &ra_cnt, end); + if (exfat_ent_set(sb, chain, chain + 1)) return -EIO; chain++;