Signed-off-by: Jaco Kroon <jaco@xxxxxxxxx> --- fs/fuse/Kconfig | 16 ++++++++++++++++ fs/fuse/readdir.c | 42 ++++++++++++++++++++++++------------------ 2 files changed, 40 insertions(+), 18 deletions(-) diff --git a/fs/fuse/Kconfig b/fs/fuse/Kconfig index 038ed0b9aaa5..0783f9ee5cd3 100644 --- a/fs/fuse/Kconfig +++ b/fs/fuse/Kconfig @@ -18,6 +18,22 @@ config FUSE_FS If you want to develop a userspace FS, or if you want to use a filesystem based on FUSE, answer Y or M. +config FUSE_READDIR_ORDER + int + range 0 5 + default 5 + help + readdir performance varies greatly depending on the size of the read. + Larger buffers results in larger reads, thus fewer reads and higher + performance in return. + + You may want to reduce this value on seriously constrained memory + systems where 128KiB (assuming 4KiB pages) cache pages is not ideal. + + This value reprents the order of the number of pages to allocate (ie, + the shift value). A value of 0 is thus 1 page (4KiB) where 5 is 32 + pages (128KiB). + config CUSE tristate "Character device in Userspace support" depends on FUSE_FS diff --git a/fs/fuse/readdir.c b/fs/fuse/readdir.c index dc603479b30e..98c62b623240 100644 --- a/fs/fuse/readdir.c +++ b/fs/fuse/readdir.c @@ -13,6 +13,12 @@ #include <linux/pagemap.h> #include <linux/highmem.h> +#define READDIR_PAGES_ORDER CONFIG_FUSE_READDIR_ORDER +#define READDIR_PAGES (1 << READDIR_PAGES_ORDER) +#define READDIR_PAGES_SIZE (PAGE_SIZE << READDIR_PAGES_ORDER) +#define READDIR_PAGES_MASK (READDIR_PAGES_SIZE - 1) +#define READDIR_PAGES_SHIFT (PAGE_SHIFT + READDIR_PAGES_ORDER) + static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx) { struct fuse_conn *fc = get_fuse_conn(dir); @@ -52,10 +58,10 @@ static void fuse_add_dirent_to_cache(struct file *file, } version = fi->rdc.version; size = fi->rdc.size; - offset = size & ~PAGE_MASK; - index = size >> PAGE_SHIFT; + offset = size & ~READDIR_PAGES_MASK; + index = size >> READDIR_PAGES_SHIFT; /* Dirent doesn't fit in current page? Jump to next page. */ - if (offset + reclen > PAGE_SIZE) { + if (offset + reclen > READDIR_PAGES_SIZE) { index++; offset = 0; } @@ -83,7 +89,7 @@ static void fuse_add_dirent_to_cache(struct file *file, } memcpy(addr + offset, dirent, reclen); kunmap_local(addr); - fi->rdc.size = (index << PAGE_SHIFT) + offset + reclen; + fi->rdc.size = (index << READDIR_PAGES_SHIFT) + offset + reclen; fi->rdc.pos = dirent->off; unlock: spin_unlock(&fi->rdc.lock); @@ -104,7 +110,7 @@ static void fuse_readdir_cache_end(struct file *file, loff_t pos) } fi->rdc.cached = true; - end = ALIGN(fi->rdc.size, PAGE_SIZE); + end = ALIGN(fi->rdc.size, READDIR_PAGES_SIZE); spin_unlock(&fi->rdc.lock); /* truncate unused tail of cache */ @@ -328,25 +334,25 @@ static int fuse_readdir_uncached(struct file *file, struct dir_context *ctx) struct fuse_mount *fm = get_fuse_mount(inode); struct fuse_io_args ia = {}; struct fuse_args_pages *ap = &ia.ap; - struct fuse_page_desc desc = { .length = PAGE_SIZE }; + struct fuse_page_desc desc = { .length = READDIR_PAGES_SIZE }; u64 attr_version = 0; bool locked; - page = alloc_page(GFP_KERNEL); + page = alloc_pages(GFP_KERNEL, READDIR_PAGES_ORDER); if (!page) return -ENOMEM; plus = fuse_use_readdirplus(inode, ctx); ap->args.out_pages = true; - ap->num_pages = 1; + ap->num_pages = READDIR_PAGES; ap->pages = &page; ap->descs = &desc; if (plus) { attr_version = fuse_get_attr_version(fm->fc); - fuse_read_args_fill(&ia, file, ctx->pos, PAGE_SIZE, + fuse_read_args_fill(&ia, file, ctx->pos, READDIR_PAGES_SIZE, FUSE_READDIRPLUS); } else { - fuse_read_args_fill(&ia, file, ctx->pos, PAGE_SIZE, + fuse_read_args_fill(&ia, file, ctx->pos, READDIR_PAGES_SIZE, FUSE_READDIR); } locked = fuse_lock_inode(inode); @@ -383,7 +389,7 @@ static enum fuse_parse_result fuse_parse_cache(struct fuse_file *ff, void *addr, unsigned int size, struct dir_context *ctx) { - unsigned int offset = ff->readdir.cache_off & ~PAGE_MASK; + unsigned int offset = ff->readdir.cache_off & ~READDIR_PAGES_MASK; enum fuse_parse_result res = FOUND_NONE; WARN_ON(offset >= size); @@ -504,16 +510,16 @@ static int fuse_readdir_cached(struct file *file, struct dir_context *ctx) WARN_ON(fi->rdc.size < ff->readdir.cache_off); - index = ff->readdir.cache_off >> PAGE_SHIFT; + index = ff->readdir.cache_off >> READDIR_PAGES_SHIFT; - if (index == (fi->rdc.size >> PAGE_SHIFT)) - size = fi->rdc.size & ~PAGE_MASK; + if (index == (fi->rdc.size >> READDIR_PAGES_SHIFT)) + size = fi->rdc.size & ~READDIR_PAGES_MASK; else - size = PAGE_SIZE; + size = READDIR_PAGES_SIZE; spin_unlock(&fi->rdc.lock); /* EOF? */ - if ((ff->readdir.cache_off & ~PAGE_MASK) == size) + if ((ff->readdir.cache_off & ~READDIR_PAGES_MASK) == size) return 0; page = find_get_page_flags(file->f_mapping, index, @@ -559,9 +565,9 @@ static int fuse_readdir_cached(struct file *file, struct dir_context *ctx) if (res == FOUND_ALL) return 0; - if (size == PAGE_SIZE) { + if (size == READDIR_PAGES_SIZE) { /* We hit end of page: skip to next page. */ - ff->readdir.cache_off = ALIGN(ff->readdir.cache_off, PAGE_SIZE); + ff->readdir.cache_off = ALIGN(ff->readdir.cache_off, READDIR_PAGES_SIZE); goto retry; } -- 2.41.0