* Re: [PATCH v1 6/9] exfat: remove unused parameters from exfat_get_cluster @ 2025-12-30 9:05 Yuezhang.Mo 2025-12-31 1:44 ` Chi Zhiling 0 siblings, 1 reply; 3+ messages in thread From: Yuezhang.Mo @ 2025-12-30 9:05 UTC (permalink / raw) To: chizhiling Cc: brauner, chizhiling, jack, linkinjeon, linux-fsdevel, linux-kernel, sj1557.seo, viro, willy, Yuezhang.Mo > diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c > index f9501c3a3666..1062ce470cb1 100644 > --- a/fs/exfat/inode.c > +++ b/fs/exfat/inode.c > @@ -157,28 +157,26 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset, > *clu += clu_offset; > } > } else if (ei->type == TYPE_FILE) { > - unsigned int fclus = 0; > int err = exfat_get_cluster(inode, clu_offset, > - &fclus, clu, &last_clu, 1); > + clu, &last_clu); > if (err) > return -EIO; > - > - clu_offset -= fclus; > } else { > + unsigned int fclus = 0; > /* hint information */ > if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && > ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { > - clu_offset -= ei->hint_bmap.off; > /* hint_bmap.clu should be valid */ > WARN_ON(ei->hint_bmap.clu < 2); > + fclus = ei->hint_bmap.off; > *clu = ei->hint_bmap.clu; > } > > - while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { > + while (fclus < clu_offset && *clu != EXFAT_EOF_CLUSTER) { > last_clu = *clu; > if (exfat_get_next_cluster(sb, clu)) > return -EIO; > - clu_offset--; > + fclus++; > } exfat_map_cluster() is only used for files. The code in this 'else' block is never executed and can be cleaned up. > } ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v1 6/9] exfat: remove unused parameters from exfat_get_cluster 2025-12-30 9:05 [PATCH v1 6/9] exfat: remove unused parameters from exfat_get_cluster Yuezhang.Mo @ 2025-12-31 1:44 ` Chi Zhiling 0 siblings, 0 replies; 3+ messages in thread From: Chi Zhiling @ 2025-12-31 1:44 UTC (permalink / raw) To: Yuezhang.Mo Cc: brauner, chizhiling, jack, linkinjeon, linux-fsdevel, linux-kernel, sj1557.seo, viro, willy On 12/30/25 17:05, Yuezhang.Mo@sony.com wrote: >> diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c >> index f9501c3a3666..1062ce470cb1 100644 >> --- a/fs/exfat/inode.c >> +++ b/fs/exfat/inode.c >> @@ -157,28 +157,26 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset, >> *clu += clu_offset; >> } >> } else if (ei->type == TYPE_FILE) { >> - unsigned int fclus = 0; >> int err = exfat_get_cluster(inode, clu_offset, >> - &fclus, clu, &last_clu, 1); >> + clu, &last_clu); >> if (err) >> return -EIO; >> - >> - clu_offset -= fclus; >> } else { >> + unsigned int fclus = 0; >> /* hint information */ >> if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && >> ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { >> - clu_offset -= ei->hint_bmap.off; >> /* hint_bmap.clu should be valid */ >> WARN_ON(ei->hint_bmap.clu < 2); >> + fclus = ei->hint_bmap.off; >> *clu = ei->hint_bmap.clu; >> } >> >> - while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { >> + while (fclus < clu_offset && *clu != EXFAT_EOF_CLUSTER) { >> last_clu = *clu; >> if (exfat_get_next_cluster(sb, clu)) >> return -EIO; >> - clu_offset--; >> + fclus++; >> } > > exfat_map_cluster() is only used for files. The code in this 'else' block is never executed and > can be cleaned up. Thanks for confirming that. It was confusing me. I'll clear this up in the next version. Thanks, > >> } > ^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH v1 0/9] Enable exfat_get_block to support obtaining multiple clusters @ 2025-12-26 9:44 Chi Zhiling 2025-12-26 9:44 ` [PATCH v1 6/9] exfat: remove unused parameters from exfat_get_cluster Chi Zhiling 0 siblings, 1 reply; 3+ messages in thread From: Chi Zhiling @ 2025-12-26 9:44 UTC (permalink / raw) To: linux-fsdevel, linux-kernel Cc: Namjae Jeon, Sungjong Seo, Yuezhang Mo, Alexander Viro, Christian Brauner, Jan Kara, Matthew Wilcox, Chi Zhiling From: Chi Zhiling <chizhiling@kylinos.cn> This patch series significantly improves exFAT read performance by adding multi-cluster mapping support. The changes reduce get_block calls during sequential reads, particularly benefiting small cluster sizes. - Extends exfat_get_cluster() and exfat_map_cluster() to handle multiple contiguous clusters - Adds buffer head caching for FAT table reads Performance results show ~10% improvement for 512-byte clusters (454->511 MB/s) and reduced get_block overhead from 10.8% to 0.02% for NO_FAT_CHAIN files. All criticism and suggestions are welcome :) Chi Zhiling (9): exfat: add cache option for __exfat_ent_get exfat: support reuse buffer head for exfat_ent_get exfat: reuse cache to improve exfat_get_cluster exfat: improve exfat_count_num_clusters exfat: improve exfat_find_last_cluster exfat: remove unused parameters from exfat_get_cluster exfat: tweak exfat_cache_lookup to support zero offset cluster exfat: support multi-cluster for exfat_map_cluster exfat: support multi-cluster for exfat_get_cluster fs/exfat/cache.c | 108 ++++++++++++++++++++++++++++---------------- fs/exfat/exfat_fs.h | 7 ++- fs/exfat/fatent.c | 61 ++++++++++++++++--------- fs/exfat/inode.c | 46 +++++++++++-------- 4 files changed, 137 insertions(+), 85 deletions(-) -- 2.43.0 ^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH v1 6/9] exfat: remove unused parameters from exfat_get_cluster 2025-12-26 9:44 [PATCH v1 0/9] Enable exfat_get_block to support obtaining multiple clusters Chi Zhiling @ 2025-12-26 9:44 ` Chi Zhiling 0 siblings, 0 replies; 3+ messages in thread From: Chi Zhiling @ 2025-12-26 9:44 UTC (permalink / raw) To: linux-fsdevel, linux-kernel Cc: Namjae Jeon, Sungjong Seo, Yuezhang Mo, Alexander Viro, Christian Brauner, Jan Kara, Matthew Wilcox, Chi Zhiling From: Chi Zhiling <chizhiling@kylinos.cn> Remove the unused fclus and allow_eof parameters from exfat_get_cluster. The fclus parameter is changed to a local variable as it is not needed to be returned. The allow_eof parameter was always 1, so remove it and the associated error handling. This simplifies the function and its callers, no logical changes. Signed-off-by: Chi Zhiling <chizhiling@kylinos.cn> --- fs/exfat/cache.c | 31 +++++++++++-------------------- fs/exfat/exfat_fs.h | 3 +-- fs/exfat/inode.c | 12 +++++------- 3 files changed, 17 insertions(+), 29 deletions(-) diff --git a/fs/exfat/cache.c b/fs/exfat/cache.c index 4161b983b6af..43a6aa87c55d 100644 --- a/fs/exfat/cache.c +++ b/fs/exfat/cache.c @@ -234,8 +234,7 @@ static inline void cache_init(struct exfat_cache_id *cid, } int exfat_get_cluster(struct inode *inode, unsigned int cluster, - unsigned int *fclus, unsigned int *dclus, - unsigned int *last_dclus, int allow_eof) + unsigned int *dclus, unsigned int *last_dclus) { struct super_block *sb = inode->i_sb; struct exfat_sb_info *sbi = EXFAT_SB(sb); @@ -243,7 +242,7 @@ int exfat_get_cluster(struct inode *inode, unsigned int cluster, struct exfat_inode_info *ei = EXFAT_I(inode); struct buffer_head *bh = NULL; struct exfat_cache_id cid; - unsigned int content; + unsigned int content, fclus; if (ei->start_clu == EXFAT_FREE_CLUSTER) { exfat_fs_error(sb, @@ -252,7 +251,7 @@ int exfat_get_cluster(struct inode *inode, unsigned int cluster, return -EIO; } - *fclus = 0; + fclus = 0; *dclus = ei->start_clu; *last_dclus = *dclus; @@ -264,7 +263,7 @@ int exfat_get_cluster(struct inode *inode, unsigned int cluster, cache_init(&cid, EXFAT_EOF_CLUSTER, EXFAT_EOF_CLUSTER); - if (exfat_cache_lookup(inode, cluster, &cid, fclus, dclus) == + if (exfat_cache_lookup(inode, cluster, &cid, &fclus, dclus) == EXFAT_EOF_CLUSTER) { /* * dummy, always not contiguous @@ -276,15 +275,15 @@ int exfat_get_cluster(struct inode *inode, unsigned int cluster, cid.nr_contig != 0); } - if (*fclus == cluster) + if (fclus == cluster) return 0; - while (*fclus < cluster) { + while (fclus < cluster) { /* prevent the infinite loop of cluster chain */ - if (*fclus > limit) { + if (fclus > limit) { exfat_fs_error(sb, "detected the cluster chain loop (i_pos %u)", - (*fclus)); + fclus); goto err; } @@ -293,21 +292,13 @@ int exfat_get_cluster(struct inode *inode, unsigned int cluster, *last_dclus = *dclus; *dclus = content; - (*fclus)++; - - if (content == EXFAT_EOF_CLUSTER) { - if (!allow_eof) { - exfat_fs_error(sb, - "invalid cluster chain (i_pos %u, last_clus 0x%08x is EOF)", - *fclus, (*last_dclus)); - goto err; - } + fclus++; + if (content == EXFAT_EOF_CLUSTER) break; - } if (!cache_contiguous(&cid, *dclus)) - cache_init(&cid, *fclus, *dclus); + cache_init(&cid, fclus, *dclus); } brelse(bh); diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h index f7f25e0600c7..e58d8eed5495 100644 --- a/fs/exfat/exfat_fs.h +++ b/fs/exfat/exfat_fs.h @@ -486,8 +486,7 @@ int exfat_cache_init(void); void exfat_cache_shutdown(void); void exfat_cache_inval_inode(struct inode *inode); int exfat_get_cluster(struct inode *inode, unsigned int cluster, - unsigned int *fclus, unsigned int *dclus, - unsigned int *last_dclus, int allow_eof); + unsigned int *dclus, unsigned int *last_dclus); /* dir.c */ extern const struct inode_operations exfat_dir_inode_operations; diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c index f9501c3a3666..1062ce470cb1 100644 --- a/fs/exfat/inode.c +++ b/fs/exfat/inode.c @@ -157,28 +157,26 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset, *clu += clu_offset; } } else if (ei->type == TYPE_FILE) { - unsigned int fclus = 0; int err = exfat_get_cluster(inode, clu_offset, - &fclus, clu, &last_clu, 1); + clu, &last_clu); if (err) return -EIO; - - clu_offset -= fclus; } else { + unsigned int fclus = 0; /* hint information */ if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER && ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) { - clu_offset -= ei->hint_bmap.off; /* hint_bmap.clu should be valid */ WARN_ON(ei->hint_bmap.clu < 2); + fclus = ei->hint_bmap.off; *clu = ei->hint_bmap.clu; } - while (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) { + while (fclus < clu_offset && *clu != EXFAT_EOF_CLUSTER) { last_clu = *clu; if (exfat_get_next_cluster(sb, clu)) return -EIO; - clu_offset--; + fclus++; } } -- 2.43.0 ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2025-12-31 1:45 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2025-12-30 9:05 [PATCH v1 6/9] exfat: remove unused parameters from exfat_get_cluster Yuezhang.Mo 2025-12-31 1:44 ` Chi Zhiling -- strict thread matches above, loose matches on Subject: below -- 2025-12-26 9:44 [PATCH v1 0/9] Enable exfat_get_block to support obtaining multiple clusters Chi Zhiling 2025-12-26 9:44 ` [PATCH v1 6/9] exfat: remove unused parameters from exfat_get_cluster Chi Zhiling
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