From: Hongbo Li <lihongbo22@huawei.com> Offering: HULK hulk inclusion category: feature bugzilla: NA -------------------------------- After the user obtains the events, the following action should be done. For async events, MFS provides the readahead command for any range of the file. And this is different with the default readahead system call such as posix_fadvise which limits the io size. For sync events, the user should fetch the raw data from remote storage server and write to fd. After handling the target event, the user should execute the IOC_DONE command to notify the sync event has been handled which will wakeup the waiting io in kernel. Signed-off-by: Huang Xiaojia <huangxiaojia2@huawei.com> Signed-off-by: Hongbo Li <lihongbo22@huawei.com> --- fs/mfs/cache.c | 206 +++++++++++++++++++++++++++++++++++++++ include/uapi/linux/mfs.h | 20 ++++ 2 files changed, 226 insertions(+) diff --git a/fs/mfs/cache.c b/fs/mfs/cache.c index da1ef8432e95..0466f6aefe6f 100644 --- a/fs/mfs/cache.c +++ b/fs/mfs/cache.c @@ -5,13 +5,219 @@ #include <linux/anon_inodes.h> #include <linux/mfs.h> +#include <linux/fadvise.h> +#include <linux/rwsem.h> +#include <linux/pagemap.h> /* * Used for cache object */ static struct kmem_cache *mfs_cobject_cachep; +static int fd_release(struct inode *inode, struct file *file) +{ + struct mfs_cache_object *object = file->private_data; + + down_write(&object->rwsem); + if (object->fd > 0) { + object->fd = -1; + object->anon_file = NULL; + iput(object->mfs_inode); + } + up_write(&object->rwsem); + return 0; +} + +static ssize_t fd_write_iter(struct kiocb *iocb, struct iov_iter *iter) +{ + struct file *ori_file = iocb->ki_filp; + struct mfs_cache_object *object = ori_file->private_data; + struct mfs_sb_info *sbi = MFS_SB(object->mfs_inode->i_sb); + ssize_t ret; + + if (!test_bit(MFS_CACHE_READY, &sbi->caches.flags)) + return -EINVAL; + if (sbi->mode != MFS_MODE_REMOTE) + return -EOPNOTSUPP; + + iocb->ki_filp = object->cache_file; + ret = vfs_iocb_iter_write(object->cache_file, iocb, iter); + iocb->ki_filp = ori_file; + return ret; +} + +static loff_t fd_llseek(struct file *filp, loff_t pos, int whence) +{ + struct mfs_cache_object *object = filp->private_data; + struct mfs_sb_info *sbi = MFS_SB(object->mfs_inode->i_sb); + + if (!test_bit(MFS_CACHE_READY, &sbi->caches.flags)) + return -EINVAL; + if (sbi->mode != MFS_MODE_REMOTE) + return -EOPNOTSUPP; + + return vfs_llseek(object->cache_file, pos, whence); +} + +/* Used for sync events */ +static long _ioc_done(struct mfs_cache_object *object, + struct mfs_ioc_done *done) +{ + struct mfs_sb_info *sbi = MFS_SB(object->mfs_inode->i_sb); + struct mfs_caches *caches = &sbi->caches; + XA_STATE(xas, &caches->events, done->id); + struct mfs_syncer *syncer; + struct mfs_event *event; + + xas_lock(&xas); + event = xas_load(&xas); + if (!event || event->object != object) { + xa_unlock(&caches->events); + return -EINVAL; + } + xas_store(&xas, NULL); + xas_unlock(&xas); + + syncer = event->syncer; + if (done->ret) + atomic_cmpxchg(&syncer->res, 0, -EIO); + spin_lock(&syncer->list_lock); + list_del(&event->link); + spin_unlock(&syncer->list_lock); + if (atomic_dec_return(&syncer->notback) == 0) + complete(&syncer->done); + put_mfs_event(event); + return 0; +} + +static void force_ra(struct address_space *mapping, struct file *file, + pgoff_t start, pgoff_t end) +{ + unsigned long default_pages = (4 * 1024 * 1024) / PAGE_SIZE; + DEFINE_READAHEAD(ractl, file, NULL, mapping, start); + pgoff_t index = start; + unsigned long nr_to_read; + + nr_to_read = end - start + 1; + while (nr_to_read) { + if (default_pages > nr_to_read) + default_pages = nr_to_read; + if (index > end) + return; + ractl._index = index; + page_cache_ra_unbounded(&ractl, default_pages, 0); + index += default_pages; + nr_to_read -= default_pages; + } +} + +/* Used for async events */ +static long _ioc_ra(struct mfs_cache_object *object, + struct mfs_ioc_ra *ra) +{ + struct file *file = object->cache_file; + struct address_space *mapping = file->f_mapping; + struct inode *inode = file_inode(file); + loff_t endbyte, isize; + pgoff_t start, end; + + isize = i_size_read(inode); + if (!isize) + return 0; + if (ra->off >= isize) + return -EINVAL; + endbyte = (u64)ra->off + (u64)ra->len; + if (!ra->len || endbyte < ra->len) + endbyte = LLONG_MAX; + else + endbyte--; + endbyte = min_t(loff_t, endbyte, isize); + + start = ra->off >> PAGE_SHIFT; + end = endbyte >> PAGE_SHIFT; + + force_ra(mapping, file, start, end); + return 0; +} + +static long fd_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + struct mfs_cache_object *object = filp->private_data; + struct mfs_sb_info *sbi = MFS_SB(object->mfs_inode->i_sb); + int ret = 0; + + if (!test_bit(MFS_CACHE_READY, &sbi->caches.flags)) + return -EINVAL; + + switch (cmd) { + case MFS_IOC_DONE: + { + struct mfs_ioc_done done; + + if (sbi->mode != MFS_MODE_REMOTE) + return -EOPNOTSUPP; + if (copy_from_user(&done, (void __user *)arg, sizeof(done))) + return -EFAULT; + ret = _ioc_done(object, &done); + break; + } + case MFS_IOC_RA: + { + struct mfs_ioc_ra ra; + + if (sbi->mode != MFS_MODE_LOCAL) + return -EOPNOTSUPP; + if (copy_from_user(&ra, (void __user *)arg, sizeof(ra))) + return -EFAULT; + ret = _ioc_ra(object, &ra); + break; + } + case MFS_IOC_RPATH: + { + struct mfs_ioc_rpath __user *ua = (struct mfs_ioc_rpath __user *)arg; + struct mfs_ioc_rpath *rpath; + int plen, clen; + u32 bytes; + char *p; + + if (get_user(bytes, &ua->max)) + return -EFAULT; + rpath = kzalloc(bytes + sizeof(struct mfs_ioc_rpath), GFP_KERNEL); + if (!rpath) + return -ENOMEM; + + rpath->max = bytes; + p = file_path(object->cache_file, rpath->d, rpath->max); + if (IS_ERR(p)) { + kfree(rpath); + return PTR_ERR(p); + } + plen = strlen(p), clen = strlen(sbi->cachedir); + if (plen <= clen) { + kfree(rpath); + return -EFAULT; + } + rpath->len = plen - clen; + /* include the tailing nil */ + memmove(rpath->d, p + clen, rpath->len + 1); + if (copy_to_user((void __user *)arg, rpath, + rpath->len + 1 + sizeof(struct mfs_ioc_rpath))) + ret = -EFAULT; + kfree(rpath); + break; + } + default: + return -EINVAL; + } + return ret; +} + static const struct file_operations mfs_fd_fops = { + .owner = THIS_MODULE, + .release = fd_release, + .write_iter = fd_write_iter, + .llseek = fd_llseek, + .unlocked_ioctl = fd_ioctl, }; static int mfs_setup_object(struct mfs_cache_object *object, diff --git a/include/uapi/linux/mfs.h b/include/uapi/linux/mfs.h index 1e4e253dbdd4..a7d5882b5e50 100644 --- a/include/uapi/linux/mfs.h +++ b/include/uapi/linux/mfs.h @@ -18,6 +18,26 @@ enum { MFS_MODE_REMOTE, }; +struct mfs_ioc_ra { + __u64 off; + __u64 len; +}; + +struct mfs_ioc_done { + __u32 id; + __u32 ret; +}; + +struct mfs_ioc_rpath { + __u16 max; + __u16 len; + __u8 d[]; +}; + +#define MFS_IOC_RA _IOW(0xbc, 1, struct mfs_ioc_ra) +#define MFS_IOC_DONE _IOW(0xbc, 2, struct mfs_ioc_done) +#define MFS_IOC_RPATH _IOWR(0xbc, 3, struct mfs_ioc_rpath) + struct mfs_ioc_fsinfo { __u8 mode; /* 0: none, 1: local, 2: remote */ }; -- 2.25.1