Replace FUSE_MAX_PAGES_PER_REQ with the configurable mount parameter max_pages to improve performance. Old RFC with detailed description of the problem and many fixes by Mitsuo Hayasaka (mitsuo.hayasaka.hu@xxxxxxxxxxx): - https://lkml.org/lkml/2012/7/5/136 Changes in v2: - add limitation by pipe_max_size, which was requested in https://lkml.org/lkml/2012/7/12/32 Changes in v1: https://lkml.org/lkml/2017/8/6/194 - replace FUSE_MAX_PAGES_PER_REQ with FUSE_DEFAULT_MAX_PAGES_PER_REQ and fc->max_pages - add mount option max_pages Signed-off-by: Constantine Shulyupin <const@xxxxxxxxxxxxx> --- Documentation/filesystems/fuse.txt | 5 ++- fs/fuse/dev.c | 4 +-- fs/fuse/file.c | 54 +++++++++++++++--------------- fs/fuse/fuse_i.h | 5 ++- fs/fuse/inode.c | 15 +++++++++ fs/pipe.c | 1 + 6 files changed, 53 insertions(+), 31 deletions(-) diff --git a/Documentation/filesystems/fuse.txt b/Documentation/filesystems/fuse.txt index 13af4a49e7db..d4e832fe9ce6 100644 --- a/Documentation/filesystems/fuse.txt +++ b/Documentation/filesystems/fuse.txt @@ -108,7 +108,10 @@ Mount options With this option the maximum size of read operations can be set. The default is infinite. Note that the size of read requests is - limited anyway to 32 pages (which is 128kbyte on i386). + limited anyway to max_pages (which by default is 32 or 128KB on x86). + +'max_pages=N' + Maximal number of pages per request. The default is 32 or 128KB on x86. 'blksize=N' diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index e03ca14f40e9..f51100505c5b 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1648,7 +1648,7 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, unsigned int num; unsigned int offset; size_t total_len = 0; - int num_pages; + unsigned num_pages; offset = outarg->offset & ~PAGE_MASK; file_size = i_size_read(inode); @@ -1660,7 +1660,7 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, num = file_size - outarg->offset; num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; - num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ); + num_pages = min(num_pages, fc->max_pages); req = fuse_get_req(fc, num_pages); if (IS_ERR(req)) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index a201fb0ac64f..e145a3ef0439 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -847,11 +847,11 @@ static int fuse_readpages_fill(void *_data, struct page *page) fuse_wait_on_page_writeback(inode, page->index); if (req->num_pages && - (req->num_pages == FUSE_MAX_PAGES_PER_REQ || + (req->num_pages == fc->max_pages || (req->num_pages + 1) * PAGE_SIZE > fc->max_read || req->pages[req->num_pages - 1]->index + 1 != page->index)) { int nr_alloc = min_t(unsigned, data->nr_pages, - FUSE_MAX_PAGES_PER_REQ); + fc->max_pages); fuse_send_readpages(req, data->file); if (fc->async_read) req = fuse_get_req_for_background(fc, nr_alloc); @@ -885,7 +885,7 @@ static int fuse_readpages(struct file *file, struct address_space *mapping, struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_fill_data data; int err; - int nr_alloc = min_t(unsigned, nr_pages, FUSE_MAX_PAGES_PER_REQ); + int nr_alloc = min_t(unsigned, nr_pages, fc->max_pages); err = -EIO; if (is_bad_inode(inode)) @@ -1100,12 +1100,12 @@ static ssize_t fuse_fill_write_pages(struct fuse_req *req, return count > 0 ? count : err; } -static inline unsigned fuse_wr_pages(loff_t pos, size_t len) +static inline unsigned fuse_wr_pages(loff_t pos, size_t len, unsigned max_pages) { return min_t(unsigned, ((pos + len - 1) >> PAGE_SHIFT) - (pos >> PAGE_SHIFT) + 1, - FUSE_MAX_PAGES_PER_REQ); + max_pages); } static ssize_t fuse_perform_write(struct kiocb *iocb, @@ -1127,7 +1127,8 @@ static ssize_t fuse_perform_write(struct kiocb *iocb, do { struct fuse_req *req; ssize_t count; - unsigned nr_pages = fuse_wr_pages(pos, iov_iter_count(ii)); + unsigned nr_pages = fuse_wr_pages(pos, iov_iter_count(ii), + fc->max_pages); req = fuse_get_req(fc, nr_pages); if (IS_ERR(req)) { @@ -1317,11 +1318,6 @@ static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii, return ret < 0 ? ret : 0; } -static inline int fuse_iter_npages(const struct iov_iter *ii_p) -{ - return iov_iter_npages(ii_p, FUSE_MAX_PAGES_PER_REQ); -} - ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, loff_t *ppos, int flags) { @@ -1341,9 +1337,10 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, int err = 0; if (io->async) - req = fuse_get_req_for_background(fc, fuse_iter_npages(iter)); + req = fuse_get_req_for_background(fc, iov_iter_npages(iter, + fc->max_pages)); else - req = fuse_get_req(fc, fuse_iter_npages(iter)); + req = fuse_get_req(fc, iov_iter_npages(iter, fc->max_pages)); if (IS_ERR(req)) return PTR_ERR(req); @@ -1388,9 +1385,10 @@ ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, fuse_put_request(fc, req); if (io->async) req = fuse_get_req_for_background(fc, - fuse_iter_npages(iter)); + iov_iter_npages(iter, fc->max_pages)); else - req = fuse_get_req(fc, fuse_iter_npages(iter)); + req = fuse_get_req(fc, iov_iter_npages(iter, + fc->max_pages)); if (IS_ERR(req)) break; } @@ -1817,7 +1815,7 @@ static int fuse_writepages_fill(struct page *page, is_writeback = fuse_page_is_writeback(inode, page->index); if (req && req->num_pages && - (is_writeback || req->num_pages == FUSE_MAX_PAGES_PER_REQ || + (is_writeback || req->num_pages == fc->max_pages || (req->num_pages + 1) * PAGE_SIZE > fc->max_write || data->orig_pages[req->num_pages - 1]->index + 1 != page->index)) { fuse_writepages_send(data); @@ -1845,7 +1843,7 @@ static int fuse_writepages_fill(struct page *page, struct fuse_inode *fi = get_fuse_inode(inode); err = -ENOMEM; - req = fuse_request_alloc_nofs(FUSE_MAX_PAGES_PER_REQ); + req = fuse_request_alloc_nofs(fc->max_pages); if (!req) { __free_page(tmp_page); goto out_unlock; @@ -1902,6 +1900,7 @@ static int fuse_writepages(struct address_space *mapping, struct writeback_control *wbc) { struct inode *inode = mapping->host; + struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_fill_wb_data data; int err; @@ -1914,7 +1913,7 @@ static int fuse_writepages(struct address_space *mapping, data.ff = NULL; err = -ENOMEM; - data.orig_pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, + data.orig_pages = kcalloc(fc->max_pages, sizeof(struct page *), GFP_NOFS); if (!data.orig_pages) @@ -2385,10 +2384,11 @@ static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src, } /* Make sure iov_length() won't overflow */ -static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count) +static int fuse_verify_ioctl_iov(struct fuse_conn *fc, struct iovec *iov, + size_t count) { size_t n; - u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT; + u32 max = fc->max_pages << PAGE_SHIFT; for (n = 0; n < count; n++, iov++) { if (iov->iov_len > (size_t) max) @@ -2512,7 +2512,7 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE); err = -ENOMEM; - pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, sizeof(pages[0]), GFP_KERNEL); + pages = kcalloc(fc->max_pages, sizeof(pages[0]), GFP_KERNEL); iov_page = (struct iovec *) __get_free_page(GFP_KERNEL); if (!pages || !iov_page) goto out; @@ -2551,7 +2551,7 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, /* make sure there are enough buffer pages and init request with them */ err = -ENOMEM; - if (max_pages > FUSE_MAX_PAGES_PER_REQ) + if (max_pages > fc->max_pages) goto out; while (num_pages < max_pages) { pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); @@ -2638,11 +2638,11 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, in_iov = iov_page; out_iov = in_iov + in_iovs; - err = fuse_verify_ioctl_iov(in_iov, in_iovs); + err = fuse_verify_ioctl_iov(fc, in_iov, in_iovs); if (err) goto out; - err = fuse_verify_ioctl_iov(out_iov, out_iovs); + err = fuse_verify_ioctl_iov(fc, out_iov, out_iovs); if (err) goto out; @@ -2833,9 +2833,9 @@ static void fuse_do_truncate(struct file *file) fuse_do_setattr(file_dentry(file), &attr, file); } -static inline loff_t fuse_round_up(loff_t off) +static inline loff_t fuse_round_up(struct fuse_conn *fc, loff_t off) { - return round_up(off, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT); + return round_up(off, fc->max_pages << PAGE_SHIFT); } static ssize_t @@ -2864,7 +2864,7 @@ fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter) if (async_dio && iov_iter_rw(iter) != WRITE && offset + count > i_size) { if (offset >= i_size) return 0; - iov_iter_truncate(iter, fuse_round_up(i_size - offset)); + iov_iter_truncate(iter, fuse_round_up(ff->fc, i_size - offset)); count = iov_iter_count(iter); } diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 5256ad333b05..64fafe78759e 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -29,7 +29,7 @@ #include <linux/user_namespace.h> /** Max number of pages that can be used in a single read request */ -#define FUSE_MAX_PAGES_PER_REQ 32 +#define FUSE_DEFAULT_MAX_PAGES_PER_REQ 32 /** Bias for fi->writectr, meaning new writepages must not be sent */ #define FUSE_NOWRITE INT_MIN @@ -476,6 +476,9 @@ struct fuse_conn { /** Maximum write size */ unsigned max_write; + /** Maxmum number of pages that can be used in a single request */ + unsigned max_pages; + /** Input queue */ struct fuse_iqueue iq; diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 061500c72608..19eed0297e83 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -22,6 +22,7 @@ #include <linux/exportfs.h> #include <linux/posix_acl.h> #include <linux/pid_namespace.h> +#include <linux/pipe_fs_i.h> MODULE_AUTHOR("Miklos Szeredi <miklos@xxxxxxxxxx>"); MODULE_DESCRIPTION("Filesystem in Userspace"); @@ -71,6 +72,7 @@ struct fuse_mount_data { unsigned default_permissions:1; unsigned allow_other:1; unsigned max_read; + unsigned max_pages; unsigned blksize; }; @@ -450,6 +452,7 @@ enum { OPT_DEFAULT_PERMISSIONS, OPT_ALLOW_OTHER, OPT_MAX_READ, + OPT_MAX_PAGES, OPT_BLKSIZE, OPT_ERR }; @@ -462,6 +465,7 @@ static const match_table_t tokens = { {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, {OPT_ALLOW_OTHER, "allow_other"}, {OPT_MAX_READ, "max_read=%u"}, + {OPT_MAX_PAGES, "max_pages=%u"}, {OPT_BLKSIZE, "blksize=%u"}, {OPT_ERR, NULL} }; @@ -543,6 +547,12 @@ static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev, d->max_read = value; break; + case OPT_MAX_PAGES: + if (match_int(&args[0], &value)) + return 0; + d->max_pages = value; + break; + case OPT_BLKSIZE: if (!is_bdev || match_int(&args[0], &value)) return 0; @@ -574,6 +584,8 @@ static int fuse_show_options(struct seq_file *m, struct dentry *root) seq_puts(m, ",allow_other"); if (fc->max_read != ~0) seq_printf(m, ",max_read=%u", fc->max_read); + if (fc->max_pages != FUSE_DEFAULT_MAX_PAGES_PER_REQ) + seq_printf(m, ",max_pages=%u", fc->max_pages); if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) seq_printf(m, ",blksize=%lu", sb->s_blocksize); return 0; @@ -1135,6 +1147,9 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) fc->user_id = d.user_id; fc->group_id = d.group_id; fc->max_read = max_t(unsigned, 4096, d.max_read); + fc->max_pages = min_t(unsigned, pipe_max_size >> PAGE_SHIFT, + max_t(unsigned, FUSE_DEFAULT_MAX_PAGES_PER_REQ, + d.max_pages)); /* Used by get_root_inode() */ sb->s_fs_info = fc; diff --git a/fs/pipe.c b/fs/pipe.c index 7b1954caf388..a1b208eb8393 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -34,6 +34,7 @@ * be set by root in /proc/sys/fs/pipe-max-size */ unsigned int pipe_max_size = 1048576; +EXPORT_SYMBOL(pipe_max_size); /* Maximum allocatable pages per user. Hard limit is unset by default, soft * matches default values. -- 2.17.1 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
