From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxim Patlasov Subject: [PATCH 07/16] fuse: Trust kernel i_mtime only Date: Sat, 29 Jun 2013 21:44:53 +0400 Message-ID: <20130629174446.20175.25189.stgit@maximpc.sw.ru> References: <20130629172211.20175.70154.stgit@maximpc.sw.ru> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: riel@redhat.com, dev@parallels.com, xemul@parallels.com, fuse-devel@lists.sourceforge.net, bfoster@redhat.com, linux-kernel@vger.kernel.org, jbottomley@parallels.com, linux-mm@kvack.org, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org, fengguang.wu@intel.com, devel@openvz.org, mgorman@suse.de To: miklos@szeredi.hu Return-path: In-Reply-To: <20130629172211.20175.70154.stgit@maximpc.sw.ru> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org Let the kernel maintain i_mtime locally: - clear S_NOCMTIME - implement i_op->update_time() - flush mtime on fsync and last close - update i_mtime explicitly on truncate and fallocate Fuse inode flag FUSE_I_MTIME_UPDATED serves as indication that local i_mtime should be flushed to the server eventually. Some operations (direct write, truncate, fallocate and setattr) leads to updating mtime on server. So, we can clear FUSE_I_MTIME_UPDATED when such an operation is completed. This is safe because these operations (as well as i_op->update_time and fsync) are protected by i_mutex. Signed-off-by: Maxim Patlasov --- fs/fuse/dir.c | 116 ++++++++++++++++++++++++++++++++++++++++++++++++------ fs/fuse/file.c | 38 +++++++++++++++--- fs/fuse/fuse_i.h | 6 ++- fs/fuse/inode.c | 13 +++++- 4 files changed, 151 insertions(+), 22 deletions(-) diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index b755884..cd67a0c 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -854,8 +854,11 @@ static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr, struct fuse_conn *fc = get_fuse_conn(inode); /* see the comment in fuse_change_attributes() */ - if (fc->writeback_cache && S_ISREG(inode->i_mode)) + if (fc->writeback_cache && S_ISREG(inode->i_mode)) { attr->size = i_size_read(inode); + attr->mtime = inode->i_mtime.tv_sec; + attr->mtimensec = inode->i_mtime.tv_nsec; + } stat->dev = inode->i_sb->s_dev; stat->ino = attr->ino; @@ -1565,6 +1568,89 @@ void fuse_release_nowrite(struct inode *inode) spin_unlock(&fc->lock); } +static void fuse_setattr_fill(struct fuse_conn *fc, struct fuse_req *req, + struct inode *inode, + struct fuse_setattr_in *inarg_p, + struct fuse_attr_out *outarg_p) +{ + req->in.h.opcode = FUSE_SETATTR; + req->in.h.nodeid = get_node_id(inode); + req->in.numargs = 1; + req->in.args[0].size = sizeof(*inarg_p); + req->in.args[0].value = inarg_p; + req->out.numargs = 1; + if (fc->minor < 9) + req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; + else + req->out.args[0].size = sizeof(*outarg_p); + req->out.args[0].value = outarg_p; +} + +/* + * Flush inode->i_mtime to the server + */ +int fuse_flush_mtime(struct file *file, bool nofail) +{ + struct inode *inode = file->f_mapping->host; + struct fuse_inode *fi = get_fuse_inode(inode); + struct fuse_conn *fc = get_fuse_conn(inode); + struct fuse_req *req = NULL; + struct fuse_setattr_in inarg; + struct fuse_attr_out outarg; + int err; + + if (nofail) { + req = fuse_get_req_nofail_nopages(fc, file); + } else { + req = fuse_get_req_nopages(fc); + if (IS_ERR(req)) + return PTR_ERR(req); + } + + memset(&inarg, 0, sizeof(inarg)); + memset(&outarg, 0, sizeof(outarg)); + + inarg.valid |= FATTR_MTIME; + inarg.mtime = inode->i_mtime.tv_sec; + inarg.mtimensec = inode->i_mtime.tv_nsec; + + fuse_setattr_fill(fc, req, inode, &inarg, &outarg); + fuse_request_send(fc, req); + err = req->out.h.error; + fuse_put_request(fc, req); + + if (!err) + clear_bit(FUSE_I_MTIME_UPDATED, &fi->state); + + return err; +} + +static inline void set_mtime_helper(struct inode *inode, struct timespec mtime) +{ + struct fuse_inode *fi = get_fuse_inode(inode); + + inode->i_mtime = mtime; + clear_bit(FUSE_I_MTIME_UPDATED, &fi->state); +} + +/* + * S_NOCMTIME is clear, so we need to update inode->i_mtime manually. But + * we can also clear FUSE_I_MTIME_UPDATED if FUSE_SETATTR has just changed + * mtime on server. + */ +static void fuse_set_mtime_local(struct iattr *iattr, struct inode *inode) +{ + unsigned ivalid = iattr->ia_valid; + + if ((ivalid & ATTR_MTIME) && update_mtime(ivalid)) { + if (ivalid & ATTR_MTIME_SET) + set_mtime_helper(inode, iattr->ia_mtime); + else + set_mtime_helper(inode, current_fs_time(inode->i_sb)); + } else if (ivalid & ATTR_SIZE) + set_mtime_helper(inode, current_fs_time(inode->i_sb)); +} + /* * Set attributes, and at the same time refresh them. * @@ -1621,17 +1707,7 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr, inarg.valid |= FATTR_LOCKOWNER; inarg.lock_owner = fuse_lock_owner_id(fc, current->files); } - req->in.h.opcode = FUSE_SETATTR; - req->in.h.nodeid = get_node_id(inode); - req->in.numargs = 1; - req->in.args[0].size = sizeof(inarg); - req->in.args[0].value = &inarg; - req->out.numargs = 1; - if (fc->minor < 9) - req->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; - else - req->out.args[0].size = sizeof(outarg); - req->out.args[0].value = &outarg; + fuse_setattr_fill(fc, req, inode, &inarg, &outarg); fuse_request_send(fc, req); err = req->out.h.error; fuse_put_request(fc, req); @@ -1648,6 +1724,10 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr, } spin_lock(&fc->lock); + /* the kernel maintains i_mtime locally */ + if (fc->writeback_cache && S_ISREG(inode->i_mode)) + fuse_set_mtime_local(attr, inode); + fuse_change_attributes_common(inode, &outarg.attr, attr_timeout(&outarg)); oldsize = inode->i_size; @@ -1872,6 +1952,17 @@ static int fuse_removexattr(struct dentry *entry, const char *name) return err; } +static int fuse_update_time(struct inode *inode, struct timespec *now, + int flags) +{ + if (flags & S_MTIME) { + inode->i_mtime = *now; + set_bit(FUSE_I_MTIME_UPDATED, &get_fuse_inode(inode)->state); + BUG_ON(!S_ISREG(inode->i_mode)); + } + return 0; +} + static const struct inode_operations fuse_dir_inode_operations = { .lookup = fuse_lookup, .mkdir = fuse_mkdir, @@ -1911,6 +2002,7 @@ static const struct inode_operations fuse_common_inode_operations = { .getxattr = fuse_getxattr, .listxattr = fuse_listxattr, .removexattr = fuse_removexattr, + .update_time = fuse_update_time, }; static const struct inode_operations fuse_symlink_inode_operations = { diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 98bc0d0..f53697c 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -291,6 +291,10 @@ static int fuse_open(struct inode *inode, struct file *file) static int fuse_release(struct inode *inode, struct file *file) { + if (test_bit(FUSE_I_MTIME_UPDATED, + &get_fuse_inode(inode)->state)) + fuse_flush_mtime(file, true); + fuse_release_common(file, FUSE_RELEASE); /* return value is ignored by VFS */ @@ -458,6 +462,13 @@ int fuse_fsync_common(struct file *file, loff_t start, loff_t end, fuse_sync_writes(inode); + if (test_bit(FUSE_I_MTIME_UPDATED, + &get_fuse_inode(inode)->state)) { + int err = fuse_flush_mtime(file, false); + if (err) + goto out; + } + req = fuse_get_req_nopages(fc); if (IS_ERR(req)) { err = PTR_ERR(req); @@ -948,16 +959,21 @@ static size_t fuse_send_write(struct fuse_req *req, struct fuse_io_priv *io, return req->misc.write.out.size; } -void fuse_write_update_size(struct inode *inode, loff_t pos) +bool fuse_write_update_size(struct inode *inode, loff_t pos) { struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_inode *fi = get_fuse_inode(inode); + bool ret = false; spin_lock(&fc->lock); fi->attr_version = ++fc->attr_version; - if (pos > inode->i_size) + if (pos > inode->i_size) { i_size_write(inode, pos); + ret = true; + } spin_unlock(&fc->lock); + + return ret; } static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file, @@ -2495,9 +2511,11 @@ fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, } if (rw == WRITE) { - if (ret > 0) + if (ret > 0) { + struct fuse_inode *fi = get_fuse_inode(inode); fuse_write_update_size(inode, pos); - else if (ret < 0 && offset + count > i_size) + clear_bit(FUSE_I_MTIME_UPDATED, &fi->state); + } else if (ret < 0 && offset + count > i_size) fuse_do_truncate(file); } @@ -2553,8 +2571,16 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset, goto out; /* we could have extended the file */ - if (!(mode & FALLOC_FL_KEEP_SIZE)) - fuse_write_update_size(inode, offset + length); + if (!(mode & FALLOC_FL_KEEP_SIZE)) { + bool changed = fuse_write_update_size(inode, offset + length); + + if (changed && fc->writeback_cache) { + struct fuse_inode *fi = get_fuse_inode(inode); + + inode->i_mtime = current_fs_time(inode->i_sb); + clear_bit(FUSE_I_MTIME_UPDATED, &fi->state); + } + } if (mode & FALLOC_FL_PUNCH_HOLE) truncate_pagecache_range(inode, offset, offset + length - 1); diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index a0062a0..82abb82 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -115,6 +115,8 @@ struct fuse_inode { enum { /** Advise readdirplus */ FUSE_I_ADVISE_RDPLUS, + /** i_mtime has been updated locally; a flush to userspace needed */ + FUSE_I_MTIME_UPDATED, }; struct fuse_conn; @@ -867,7 +869,9 @@ long fuse_ioctl_common(struct file *file, unsigned int cmd, unsigned fuse_file_poll(struct file *file, poll_table *wait); int fuse_dev_release(struct inode *inode, struct file *file); -void fuse_write_update_size(struct inode *inode, loff_t pos); +bool fuse_write_update_size(struct inode *inode, loff_t pos); + +int fuse_flush_mtime(struct file *file, bool nofail); int fuse_do_setattr(struct inode *inode, struct iattr *attr, struct file *file); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 121638d..591b46c 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -170,8 +170,11 @@ void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr, inode->i_blocks = attr->blocks; inode->i_atime.tv_sec = attr->atime; inode->i_atime.tv_nsec = attr->atimensec; - inode->i_mtime.tv_sec = attr->mtime; - inode->i_mtime.tv_nsec = attr->mtimensec; + /* mtime from server may be stale due to local buffered write */ + if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) { + inode->i_mtime.tv_sec = attr->mtime; + inode->i_mtime.tv_nsec = attr->mtimensec; + } inode->i_ctime.tv_sec = attr->ctime; inode->i_ctime.tv_nsec = attr->ctimensec; @@ -249,6 +252,8 @@ static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr) { inode->i_mode = attr->mode & S_IFMT; inode->i_size = attr->size; + inode->i_mtime.tv_sec = attr->mtime; + inode->i_mtime.tv_nsec = attr->mtimensec; if (S_ISREG(inode->i_mode)) { fuse_init_common(inode); fuse_init_file_inode(inode); @@ -295,7 +300,9 @@ struct inode *fuse_iget(struct super_block *sb, u64 nodeid, return NULL; if ((inode->i_state & I_NEW)) { - inode->i_flags |= S_NOATIME|S_NOCMTIME; + inode->i_flags |= S_NOATIME; + if (!fc->writeback_cache) + inode->i_flags |= S_NOCMTIME; inode->i_generation = generation; inode->i_data.backing_dev_info = &fc->bdi; fuse_init_inode(inode, attr); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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