diff options
| -rw-r--r-- | fs/fuse/dev.c | 19 | ||||
| -rw-r--r-- | fs/fuse/file.c | 132 | ||||
| -rw-r--r-- | fs/fuse/fuse_i.h | 20 | ||||
| -rw-r--r-- | fs/fuse/inode.c | 1 | ||||
| -rw-r--r-- | include/linux/fuse.h | 25 |
5 files changed, 197 insertions, 0 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index ffd670bb8c8..6176e444c76 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -816,10 +816,29 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov, return err; } +static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size, + struct fuse_copy_state *cs) +{ + struct fuse_notify_poll_wakeup_out outarg; + int err; + + if (size != sizeof(outarg)) + return -EINVAL; + + err = fuse_copy_one(cs, &outarg, sizeof(outarg)); + if (err) + return err; + + return fuse_notify_poll_wakeup(fc, &outarg); +} + static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code, unsigned int size, struct fuse_copy_state *cs) { switch (code) { + case FUSE_NOTIFY_POLL: + return fuse_notify_poll(fc, size, cs); + default: return -EINVAL; } diff --git a/fs/fuse/file.c b/fs/fuse/file.c index a28ced678d3..b3a944e4bb9 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -62,6 +62,8 @@ struct fuse_file *fuse_file_alloc(struct fuse_conn *fc) ff->kh = ++fc->khctr; spin_unlock(&fc->lock); } + RB_CLEAR_NODE(&ff->polled_node); + init_waitqueue_head(&ff->poll_wait); } return ff; } @@ -170,7 +172,11 @@ int fuse_release_common(struct inode *inode, struct file *file, int isdir) spin_lock(&fc->lock); list_del(&ff->write_entry); + if (!RB_EMPTY_NODE(&ff->polled_node)) + rb_erase(&ff->polled_node, &fc->polled_files); spin_unlock(&fc->lock); + + wake_up_interruptible_sync(&ff->poll_wait); /* * Normally this will send the RELEASE request, * however if some asynchronous READ or WRITE requests @@ -1749,6 +1755,130 @@ static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd, return fuse_file_do_ioctl(file, cmd, arg, FUSE_IOCTL_COMPAT); } +/* + * All files which have been polled are linked to RB tree + * fuse_conn->polled_files which is indexed by kh. Walk the tree and + * find the matching one. + */ +static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh, + struct rb_node **parent_out) +{ + struct rb_node **link = &fc->polled_files.rb_node; + struct rb_node *last = NULL; + + while (*link) { + struct fuse_file *ff; + + last = *link; + ff = rb_entry(last, struct fuse_file, polled_node); + + if (kh < ff->kh) + link = &last->rb_left; + else if (kh > ff->kh) + link = &last->rb_right; + else + return link; + } + + if (parent_out) + *parent_out = last; + return link; +} + +/* + * The file is about to be polled. Make sure it's on the polled_files + * RB tree. Note that files once added to the polled_files tree are + * not removed before the file is released. This is because a file + * polled once is likely to be polled again. + */ +static void fuse_register_polled_file(struct fuse_conn *fc, + struct fuse_file *ff) +{ + spin_lock(&fc->lock); + if (RB_EMPTY_NODE(&ff->polled_node)) { + struct rb_node **link, *parent; + + link = fuse_find_polled_node(fc, ff->kh, &parent); + BUG_ON(*link); + rb_link_node(&ff->polled_node, parent, link); + rb_insert_color(&ff->polled_node, &fc->polled_files); + } + spin_unlock(&fc->lock); +} + +static unsigned fuse_file_poll(struct file *file, poll_table *wait) +{ + struct inode *inode = file->f_dentry->d_inode; + struct fuse_file *ff = file->private_data; + struct fuse_conn *fc = get_fuse_conn(inode); + struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh }; + struct fuse_poll_out outarg; + struct fuse_req *req; + int err; + + if (fc->no_poll) + return DEFAULT_POLLMASK; + + poll_wait(file, &ff->poll_wait, wait); + + /* + * Ask for notification iff there's someone waiting for it. + * The client may ignore the flag and always notify. + */ + if (waitqueue_active(&ff->poll_wait)) { + inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY; + fuse_register_polled_file(fc, ff); + } + + req = fuse_get_req(fc); + if (IS_ERR(req)) + return PTR_ERR(req); + + req->in.h.opcode = FUSE_POLL; + 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; + req->out.args[0].size = sizeof(outarg); + req->out.args[0].value = &outarg; + request_send(fc, req); + err = req->out.h.error; + fuse_put_request(fc, req); + + if (!err) + return outarg.revents; + if (err == -ENOSYS) { + fc->no_poll = 1; + return DEFAULT_POLLMASK; + } + return POLLERR; +} + +/* + * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and + * wakes up the poll waiters. + */ +int fuse_notify_poll_wakeup(struct fuse_conn *fc, + struct fuse_notify_poll_wakeup_out *outarg) +{ + u64 kh = outarg->kh; + struct rb_node **link; + + spin_lock(&fc->lock); + + link = fuse_find_polled_node(fc, kh, NULL); + if (*link) { + struct fuse_file *ff; + + ff = rb_entry(*link, struct fuse_file, polled_node); + wake_up_interruptible_sync(&ff->poll_wait); + } + + spin_unlock(&fc->lock); + return 0; +} + static const struct file_operations fuse_file_operations = { .llseek = fuse_file_llseek, .read = do_sync_read, @@ -1765,6 +1895,7 @@ static const struct file_operations fuse_file_operations = { .splice_read = generic_file_splice_read, .unlocked_ioctl = fuse_file_ioctl, .compat_ioctl = fuse_file_compat_ioctl, + .poll = fuse_file_poll, }; static const struct file_operations fuse_direct_io_file_operations = { @@ -1779,6 +1910,7 @@ static const struct file_operations fuse_direct_io_file_operations = { .flock = fuse_file_flock, .unlocked_ioctl = fuse_file_ioctl, .compat_ioctl = fuse_file_compat_ioctl, + .poll = fuse_file_poll, /* no mmap and splice_read */ }; diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 86f01330382..986fbd4c1ff 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -19,6 +19,8 @@ #include <linux/backing-dev.h> #include <linux/mutex.h> #include <linux/rwsem.h> +#include <linux/rbtree.h> +#include <linux/poll.h> /** Max number of pages that can be used in a single read request */ #define FUSE_MAX_PAGES_PER_REQ 32 @@ -111,6 +113,12 @@ struct fuse_file { /** Entry on inode's write_files list */ struct list_head write_entry; + + /** RB node to be linked on fuse_conn->polled_files */ + struct rb_node polled_node; + + /** Wait queue head for poll */ + wait_queue_head_t poll_wait; }; /** One input argument of a request */ @@ -328,6 +336,9 @@ struct fuse_conn { /** The next unique kernel file handle */ u64 khctr; + /** rbtree of fuse_files waiting for poll events indexed by ph */ + struct rb_root polled_files; + /** Number of requests currently in the background */ unsigned num_background; @@ -416,6 +427,9 @@ struct fuse_conn { /** Is bmap not implemented by fs? */ unsigned no_bmap:1; + /** Is poll not implemented by fs? */ + unsigned no_poll:1; + /** Do multi-page cached writes */ unsigned big_writes:1; @@ -525,6 +539,12 @@ int fuse_fsync_common(struct file *file, struct dentry *de, int datasync, int isdir); /** + * Notify poll wakeup + */ +int fuse_notify_poll_wakeup(struct fuse_conn *fc, + struct fuse_notify_poll_wakeup_out *outarg); + +/** * Initialize file operations on a regular file */ void fuse_init_file_inode(struct inode *inode); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 0e15bc221d2..ba725612808 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -486,6 +486,7 @@ static struct fuse_conn *new_conn(struct super_block *sb) /* fuse does it's own writeback accounting */ fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB; fc->khctr = 0; + fc->polled_files = RB_ROOT; fc->dev = sb->s_dev; err = bdi_init(&fc->bdi); if (err) diff --git a/include/linux/fuse.h b/include/linux/fuse.h index abde9949e2c..5650cf033e7 100644 --- a/include/linux/fuse.h +++ b/include/linux/fuse.h @@ -163,6 +163,13 @@ struct fuse_file_lock { #define FUSE_IOCTL_MAX_IOV 256 +/** + * Poll flags + * + * FUSE_POLL_SCHEDULE_NOTIFY: request poll notify + */ +#define FUSE_POLL_SCHEDULE_NOTIFY (1 << 0) + enum fuse_opcode { FUSE_LOOKUP = 1, FUSE_FORGET = 2, /* no reply */ @@ -201,9 +208,11 @@ enum fuse_opcode { FUSE_BMAP = 37, FUSE_DESTROY = 38, FUSE_IOCTL = 39, + FUSE_POLL = 40, }; enum fuse_notify_code { + FUSE_NOTIFY_POLL = 1, FUSE_NOTIFY_CODE_MAX, }; @@ -421,6 +430,22 @@ struct fuse_ioctl_out { __u32 out_iovs; }; +struct fuse_poll_in { + __u64 fh; + __u64 kh; + __u32 flags; + __u32 padding; +}; + +struct fuse_poll_out { + __u32 revents; + __u32 padding; +}; + +struct fuse_notify_poll_wakeup_out { + __u64 kh; +}; + struct fuse_in_header { __u32 len; __u32 opcode; |