From 8373200b124d03de7fa2e99be56de8642e604e9e Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Thu, 10 Oct 2013 17:10:46 +0400 Subject: fuse: Trust kernel i_size only Make fuse think that when writeback is on the inode's i_size is always up-to-date and not update it with the value received from the userspace. This is done because the page cache code may update i_size without letting the FS know. This assumption implies fixing the previously introduced short-read helper -- when a short read occurs the 'hole' is filled with zeroes. fuse_file_fallocate() is also fixed because now we should keep i_size up to date, so it must be updated if FUSE_FALLOCATE request succeeded. Signed-off-by: Maxim V. Patlasov Signed-off-by: Miklos Szeredi --- fs/fuse/inode.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'fs/fuse/inode.c') diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index d468643..c668c84 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -197,6 +197,7 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, { struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_inode *fi = get_fuse_inode(inode); + bool is_wb = fc->writeback_cache; loff_t oldsize; struct timespec old_mtime; @@ -211,10 +212,16 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, fuse_change_attributes_common(inode, attr, attr_valid); oldsize = inode->i_size; - i_size_write(inode, attr->size); + /* + * In case of writeback_cache enabled, the cached writes beyond EOF + * extend local i_size without keeping userspace server in sync. So, + * attr->size coming from server can be stale. We cannot trust it. + */ + if (!is_wb || !S_ISREG(inode->i_mode)) + i_size_write(inode, attr->size); spin_unlock(&fc->lock); - if (S_ISREG(inode->i_mode)) { + if (!is_wb && S_ISREG(inode->i_mode)) { bool inval = false; if (oldsize != attr->size) { -- cgit v1.1 From b0aa760652179072119582375f8dc896ed5b5dfd Mon Sep 17 00:00:00 2001 From: Maxim Patlasov Date: Thu, 26 Dec 2013 19:51:11 +0400 Subject: fuse: Trust kernel i_mtime only 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_DIRTY serves as indication that local i_mtime should be flushed to the server eventually. Signed-off-by: Maxim Patlasov Signed-off-by: Miklos Szeredi --- fs/fuse/inode.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'fs/fuse/inode.c') diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index c668c84..1061b0d9 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; @@ -250,6 +253,8 @@ 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); @@ -296,7 +301,9 @@ 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 || !S_ISREG(inode->i_mode)) + inode->i_flags |= S_NOCMTIME; inode->i_generation = generation; inode->i_data.backing_dev_info = &fc->bdi; fuse_init_inode(inode, attr); -- cgit v1.1 From 4d99ff8f12eb20c6cde292f185cb1c8c334ba0ed Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Thu, 10 Oct 2013 17:12:18 +0400 Subject: fuse: Turn writeback cache on Introduce a bit kernel and userspace exchange between each-other on the init stage and turn writeback on if the userspace want this and mount option 'allow_wbcache' is present (controlled by fusermount). Also add each writable file into per-inode write list and call the generic_file_aio_write to make use of the Linux page cache engine. Signed-off-by: Maxim Patlasov Signed-off-by: Miklos Szeredi --- fs/fuse/inode.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'fs/fuse/inode.c') diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 1061b0d9..9ba1919 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -887,6 +887,8 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) } if (arg->flags & FUSE_ASYNC_DIO) fc->async_dio = 1; + if (arg->flags & FUSE_WRITEBACK_CACHE) + fc->writeback_cache = 1; } else { ra_pages = fc->max_read / PAGE_CACHE_SIZE; fc->no_lock = 1; @@ -914,7 +916,8 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req) FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK | FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ | FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA | - FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO; + FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO | + FUSE_WRITEBACK_CACHE; req->in.h.opcode = FUSE_INIT; req->in.numargs = 1; req->in.args[0].size = sizeof(*arg); -- cgit v1.1