From patchwork Fri Jan 10 20:00:04 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dominique Martinet X-Patchwork-Id: 3467901 Return-Path: X-Original-To: patchwork-v9fs-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 4FA979F374 for ; Fri, 10 Jan 2014 20:01:42 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CE39A2013A for ; Fri, 10 Jan 2014 20:01:40 +0000 (UTC) Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 305992012F for ; Fri, 10 Jan 2014 20:01:39 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=sfs-ml-3.v29.ch3.sourceforge.com) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1W1iGb-0007F2-DS; Fri, 10 Jan 2014 20:01:17 +0000 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1W1iGZ-0007Ev-2Z for v9fs-developer@lists.sourceforge.net; Fri, 10 Jan 2014 20:01:15 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of notk.org designates 91.121.71.147 as permitted sender) client-ip=91.121.71.147; envelope-from=asmadeus@notk.org; helo=nautica.notk.org; Received: from nautica.notk.org ([91.121.71.147]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1W1iGX-0000U9-4J for v9fs-developer@lists.sourceforge.net; Fri, 10 Jan 2014 20:01:15 +0000 Received: by nautica.notk.org (Postfix, from userid 1001) id DBA87C009; Fri, 10 Jan 2014 21:01:06 +0100 (CET) From: Dominique Martinet To: Eric Van Hensbergen , v9fs-developer@lists.sourceforge.net, Randy Dunlap Date: Fri, 10 Jan 2014 21:00:04 +0100 Message-Id: <1389384004-5685-1-git-send-email-dominique.martinet@cea.fr> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <52D04820.4090500@infradead.org> References: <52D04820.4090500@infradead.org> X-Spam-Score: -1.6 (-) X-Headers-End: 1W1iGX-0000U9-4J Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [V9fs-developer] [PATCH V2] 9P: introduction of a new cache=mmap model. X-BeenThere: v9fs-developer@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: v9fs-developer-bounces@lists.sourceforge.net X-Spam-Status: No, score=-7.0 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP - Add cache=mmap option - Make mmap read-write while keeping it as synchronous as possible - Build writeback fid on mmap creation if it is writable Signed-off-by: Dominique Martinet Signed-off-by: Eric Van Hensbergen --- Same as previous with the extra 4 lines in Documentation's 9p.txt (figured we might as well want to add the explicit cache=none option) Sorry again Eric! (Which made me notice that the second line of loose = is space-aligned while fscache is tab-aligned, and there are quite a few others of the same... How are such trivial style fixes handled, in a separate patch? Or when, like here, there's something else close being changed?) Documentation/filesystems/9p.txt | 4 ++ fs/9p/v9fs.c | 9 ++- fs/9p/v9fs.h | 1 + fs/9p/v9fs_vfs.h | 2 + fs/9p/vfs_addr.c | 7 ++ fs/9p/vfs_file.c | 140 +++++++++++++++++++++++++++++++++++++-- fs/9p/vfs_inode.c | 22 ++++-- fs/9p/vfs_inode_dotl.c | 9 +-- fs/9p/vfs_super.c | 8 ++- 9 files changed, 183 insertions(+), 19 deletions(-) diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt index 2c03214..b30a477 100644 --- a/Documentation/filesystems/9p.txt +++ b/Documentation/filesystems/9p.txt @@ -69,10 +69,14 @@ OPTIONS offering several exported file systems. cache=mode specifies a caching policy. By default, no caches are used. + none = default no cache policy, metadata and data + alike are synchronous. loose = no attempts are made at consistency, intended for exclusive, read-only mounts fscache = use FS-Cache for a persistent, read-only cache backend. + mmap = minimal cache that is only used for read-write + mmap. Nothing else is cached, like cache=none. debug=n specifies debug level. The debug level is a bitmask. 0x01 = display verbose error messages diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c index 08f2e1e..14da825 100644 --- a/fs/9p/v9fs.c +++ b/fs/9p/v9fs.c @@ -56,7 +56,7 @@ enum { /* Options that take no arguments */ Opt_nodevmap, /* Cache options */ - Opt_cache_loose, Opt_fscache, + Opt_cache_loose, Opt_fscache, Opt_mmap, /* Access options */ Opt_access, Opt_posixacl, /* Error token */ @@ -74,6 +74,7 @@ static const match_table_t tokens = { {Opt_cache, "cache=%s"}, {Opt_cache_loose, "loose"}, {Opt_fscache, "fscache"}, + {Opt_mmap, "mmap"}, {Opt_cachetag, "cachetag=%s"}, {Opt_access, "access=%s"}, {Opt_posixacl, "posixacl"}, @@ -91,6 +92,9 @@ static int get_cache_mode(char *s) } else if (!strcmp(s, "fscache")) { version = CACHE_FSCACHE; p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n"); + } else if (!strcmp(s, "mmap")) { + version = CACHE_MMAP; + p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n"); } else if (!strcmp(s, "none")) { version = CACHE_NONE; p9_debug(P9_DEBUG_9P, "Cache mode: none\n"); @@ -220,6 +224,9 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts) case Opt_fscache: v9ses->cache = CACHE_FSCACHE; break; + case Opt_mmap: + v9ses->cache = CACHE_MMAP; + break; case Opt_cachetag: #ifdef CONFIG_9P_FSCACHE v9ses->cachetag = match_strdup(&args[0]); diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h index a8e127c..099c771 100644 --- a/fs/9p/v9fs.h +++ b/fs/9p/v9fs.h @@ -64,6 +64,7 @@ enum p9_session_flags { enum p9_cache_modes { CACHE_NONE, + CACHE_MMAP, CACHE_LOOSE, CACHE_FSCACHE, }; diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h index dc95a25..b83ebfb 100644 --- a/fs/9p/v9fs_vfs.h +++ b/fs/9p/v9fs_vfs.h @@ -50,6 +50,8 @@ extern const struct dentry_operations v9fs_dentry_operations; extern const struct dentry_operations v9fs_cached_dentry_operations; extern const struct file_operations v9fs_cached_file_operations; extern const struct file_operations v9fs_cached_file_operations_dotl; +extern const struct file_operations v9fs_mmap_file_operations; +extern const struct file_operations v9fs_mmap_file_operations_dotl; extern struct kmem_cache *v9fs_inode_cache; struct inode *v9fs_alloc_inode(struct super_block *sb); diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c index 9ff073f..c71e886 100644 --- a/fs/9p/vfs_addr.c +++ b/fs/9p/vfs_addr.c @@ -202,6 +202,8 @@ static int v9fs_vfs_writepage(struct page *page, struct writeback_control *wbc) { int retval; + p9_debug(P9_DEBUG_VFS, "page %p\n", page); + retval = v9fs_vfs_writepage_locked(page); if (retval < 0) { if (retval == -EAGAIN) { @@ -282,6 +284,9 @@ static int v9fs_write_begin(struct file *filp, struct address_space *mapping, pgoff_t index = pos >> PAGE_CACHE_SHIFT; struct inode *inode = mapping->host; + + p9_debug(P9_DEBUG_VFS, "filp %p, mapping %p\n", filp, mapping); + v9inode = V9FS_I(inode); start: page = grab_cache_page_write_begin(mapping, index, flags); @@ -312,6 +317,8 @@ static int v9fs_write_end(struct file *filp, struct address_space *mapping, loff_t last_pos = pos + copied; struct inode *inode = page->mapping->host; + p9_debug(P9_DEBUG_VFS, "filp %p, mapping %p\n", filp, mapping); + if (unlikely(copied < len)) { /* * zero out the rest of the area diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 27782bb..a16b0ff 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -45,6 +45,7 @@ #include "cache.h" static const struct vm_operations_struct v9fs_file_vm_ops; +static const struct vm_operations_struct v9fs_mmap_file_vm_ops; /** * v9fs_file_open - open a file (or directory) @@ -87,7 +88,8 @@ int v9fs_file_open(struct inode *inode, struct file *file) file->private_data = fid; mutex_lock(&v9inode->v_mutex); - if (v9ses->cache && !v9inode->writeback_fid && + if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) && + !v9inode->writeback_fid && ((file->f_flags & O_ACCMODE) != O_RDONLY)) { /* * clone a fid and add it to writeback_fid @@ -105,7 +107,7 @@ int v9fs_file_open(struct inode *inode, struct file *file) v9inode->writeback_fid = (void *) fid; } mutex_unlock(&v9inode->v_mutex); - if (v9ses->cache) + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) v9fs_cache_inode_set_cookie(inode, file); return 0; out_error: @@ -579,11 +581,12 @@ int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end, } static int -v9fs_file_mmap(struct file *file, struct vm_area_struct *vma) +v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma) { int retval; - retval = generic_file_mmap(file, vma); + + retval = generic_file_mmap(filp, vma); if (!retval) vma->vm_ops = &v9fs_file_vm_ops; @@ -591,6 +594,43 @@ v9fs_file_mmap(struct file *file, struct vm_area_struct *vma) } static int +v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma) +{ + int retval; + struct inode *inode; + struct v9fs_inode *v9inode; + struct p9_fid *fid; + + inode = file_inode(filp); + v9inode = V9FS_I(inode); + mutex_lock(&v9inode->v_mutex); + if (!v9inode->writeback_fid && + (vma->vm_flags & VM_WRITE)) { + /* + * clone a fid and add it to writeback_fid + * we do it during mmap instead of + * page dirty time via write_begin/page_mkwrite + * because we want write after unlink usecase + * to work. + */ + fid = v9fs_writeback_fid(filp->f_path.dentry); + if (IS_ERR(fid)) { + retval = PTR_ERR(fid); + mutex_unlock(&v9inode->v_mutex); + return retval; + } + v9inode->writeback_fid = (void *) fid; + } + mutex_unlock(&v9inode->v_mutex); + + retval = generic_file_mmap(filp, vma); + if (!retval) + vma->vm_ops = &v9fs_mmap_file_vm_ops; + + return retval; +} + +static int v9fs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) { struct v9fs_inode *v9inode; @@ -658,6 +698,22 @@ v9fs_cached_file_read(struct file *filp, char __user *data, size_t count, return do_sync_read(filp, data, count, offset); } +/** + * v9fs_mmap_file_read - read from a file + * @filp: file pointer to read + * @udata: user data buffer to read data into + * @count: size of buffer + * @offset: offset at which to read data + * + */ +static ssize_t +v9fs_mmap_file_read(struct file *filp, char __user *data, size_t count, + loff_t *offset) +{ + /* TODO: Check if there are dirty pages */ + return v9fs_file_read(filp, data, count, offset); +} + static ssize_t v9fs_direct_write(struct file *filp, const char __user * data, size_t count, loff_t *offsetp) @@ -728,12 +784,65 @@ v9fs_cached_file_write(struct file *filp, const char __user * data, return do_sync_write(filp, data, count, offset); } + +/** + * v9fs_mmap_file_write - write to a file + * @filp: file pointer to write + * @data: data buffer to write data from + * @count: size of buffer + * @offset: offset at which to write data + * + */ +static ssize_t +v9fs_mmap_file_write(struct file *filp, const char __user *data, + size_t count, loff_t *offset) +{ + /* + * TODO: invalidate mmaps on filp's inode between + * offset and offset+count + */ + return v9fs_file_write(filp, data, count, offset); +} + +static void v9fs_mmap_vm_close(struct vm_area_struct *vma) +{ + struct inode *inode; + + struct writeback_control wbc = { + .nr_to_write = LONG_MAX, + .sync_mode = WB_SYNC_ALL, + .range_start = vma->vm_pgoff * PAGE_SIZE, + /* absolute end, byte at end included */ + .range_end = vma->vm_pgoff * PAGE_SIZE + + (vma->vm_end - vma->vm_start - 1), + }; + + + p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma); + + inode = file_inode(vma->vm_file); + + if (!mapping_cap_writeback_dirty(inode->i_mapping)) + wbc.nr_to_write = 0; + + might_sleep(); + sync_inode(inode, &wbc); +} + + static const struct vm_operations_struct v9fs_file_vm_ops = { .fault = filemap_fault, .page_mkwrite = v9fs_vm_page_mkwrite, .remap_pages = generic_file_remap_pages, }; +static const struct vm_operations_struct v9fs_mmap_file_vm_ops = { + .close = v9fs_mmap_vm_close, + .fault = filemap_fault, + .page_mkwrite = v9fs_vm_page_mkwrite, + .remap_pages = generic_file_remap_pages, +}; + const struct file_operations v9fs_cached_file_operations = { .llseek = generic_file_llseek, @@ -784,3 +893,26 @@ const struct file_operations v9fs_file_operations_dotl = { .mmap = generic_file_readonly_mmap, .fsync = v9fs_file_fsync_dotl, }; + +const struct file_operations v9fs_mmap_file_operations = { + .llseek = generic_file_llseek, + .read = v9fs_mmap_file_read, + .write = v9fs_mmap_file_write, + .open = v9fs_file_open, + .release = v9fs_dir_release, + .lock = v9fs_file_lock, + .mmap = v9fs_mmap_file_mmap, + .fsync = v9fs_file_fsync, +}; + +const struct file_operations v9fs_mmap_file_operations_dotl = { + .llseek = generic_file_llseek, + .read = v9fs_mmap_file_read, + .write = v9fs_mmap_file_write, + .open = v9fs_file_open, + .release = v9fs_dir_release, + .lock = v9fs_file_lock_dotl, + .flock = v9fs_file_flock_dotl, + .mmap = v9fs_mmap_file_mmap, + .fsync = v9fs_file_fsync_dotl, +}; diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index af7d531..bb7991c 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -299,15 +299,22 @@ int v9fs_init_inode(struct v9fs_session_info *v9ses, case S_IFREG: if (v9fs_proto_dotl(v9ses)) { inode->i_op = &v9fs_file_inode_operations_dotl; - if (v9ses->cache) + if (v9ses->cache == CACHE_LOOSE || + v9ses->cache == CACHE_FSCACHE) inode->i_fop = &v9fs_cached_file_operations_dotl; + else if (v9ses->cache == CACHE_MMAP) + inode->i_fop = &v9fs_mmap_file_operations_dotl; else inode->i_fop = &v9fs_file_operations_dotl; } else { inode->i_op = &v9fs_file_inode_operations; - if (v9ses->cache) - inode->i_fop = &v9fs_cached_file_operations; + if (v9ses->cache == CACHE_LOOSE || + v9ses->cache == CACHE_FSCACHE) + inode->i_fop = + &v9fs_cached_file_operations; + else if (v9ses->cache == CACHE_MMAP) + inode->i_fop = &v9fs_mmap_file_operations; else inode->i_fop = &v9fs_file_operations; } @@ -810,7 +817,7 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, * unlink. For cached mode create calls request for new * inode. But with cache disabled, lookup should do this. */ - if (v9ses->cache) + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb); else inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb); @@ -876,7 +883,8 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, v9fs_invalidate_inode_attr(dir); v9inode = V9FS_I(dentry->d_inode); mutex_lock(&v9inode->v_mutex); - if (v9ses->cache && !v9inode->writeback_fid && + if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) && + !v9inode->writeback_fid && ((flags & O_ACCMODE) != O_RDONLY)) { /* * clone a fid and add it to writeback_fid @@ -899,7 +907,7 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, goto error; file->private_data = fid; - if (v9ses->cache) + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) v9fs_cache_inode_set_cookie(dentry->d_inode, file); *opened |= FILE_CREATED; @@ -1477,7 +1485,7 @@ int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode) */ i_size = inode->i_size; v9fs_stat2inode(st, inode, inode->i_sb); - if (v9ses->cache) + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) inode->i_size = i_size; spin_unlock(&inode->i_lock); out: diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c index 9801306..59dc8e8 100644 --- a/fs/9p/vfs_inode_dotl.c +++ b/fs/9p/vfs_inode_dotl.c @@ -330,7 +330,8 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry, v9inode = V9FS_I(inode); mutex_lock(&v9inode->v_mutex); - if (v9ses->cache && !v9inode->writeback_fid && + if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) && + !v9inode->writeback_fid && ((flags & O_ACCMODE) != O_RDONLY)) { /* * clone a fid and add it to writeback_fid @@ -353,7 +354,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry, if (err) goto err_clunk_old_fid; file->private_data = ofid; - if (v9ses->cache) + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) v9fs_cache_inode_set_cookie(inode, file); *opened |= FILE_CREATED; out: @@ -710,7 +711,7 @@ v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry, } v9fs_invalidate_inode_attr(dir); - if (v9ses->cache) { + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) { /* Now walk from the parent so we can get an unopened fid. */ fid = p9_client_walk(dfid, 1, &name, 1); if (IS_ERR(fid)) { @@ -965,7 +966,7 @@ int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode) */ i_size = inode->i_size; v9fs_stat2inode_dotl(st, inode); - if (v9ses->cache) + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) inode->i_size = i_size; spin_unlock(&inode->i_lock); out: diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c index 2756dcd..0afd038 100644 --- a/fs/9p/vfs_super.c +++ b/fs/9p/vfs_super.c @@ -144,7 +144,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, } v9fs_fill_super(sb, v9ses, flags, data); - if (v9ses->cache) + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) sb->s_d_op = &v9fs_cached_dentry_operations; else sb->s_d_op = &v9fs_dentry_operations; @@ -282,7 +282,7 @@ static int v9fs_drop_inode(struct inode *inode) { struct v9fs_session_info *v9ses; v9ses = v9fs_inode2v9ses(inode); - if (v9ses->cache) + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) return generic_drop_inode(inode); /* * in case of non cached mode always drop the @@ -325,10 +325,12 @@ static int v9fs_write_inode_dotl(struct inode *inode, * send an fsync request to server irrespective of * wbc->sync_mode. */ - p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); v9inode = V9FS_I(inode); + p9_debug(P9_DEBUG_VFS, "%s: inode %p, writeback_fid %p\n", + __func__, inode, v9inode->writeback_fid); if (!v9inode->writeback_fid) return 0; + ret = p9_client_fsync(v9inode->writeback_fid, 0); if (ret < 0) { __mark_inode_dirty(inode, I_DIRTY_DATASYNC);