From 3b7008b226f3de811d4ac34238e9cf670f7c9fe7 Mon Sep 17 00:00:00 2001 From: Szymon Lukasz Date: Thu, 9 Nov 2017 21:23:35 +0100 Subject: fuse: return -ECONNABORTED on /dev/fuse read after abort Currently the userspace has no way of knowing whether the fuse connection ended because of umount or abort via sysfs. It makes it hard for filesystems to free the mountpoint after abort without worrying about removing some new mount. The patch fixes it by returning different errors when userspace reads from /dev/fuse (-ENODEV for umount and -ECONNABORTED for abort). Add a new capability flag FUSE_ABORT_ERROR. If set and the connection is gone because of sysfs abort, reading from the device will return -ECONNABORTED. Signed-off-by: Szymon Lukasz Signed-off-by: Miklos Szeredi --- fs/fuse/dev.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'fs/fuse/dev.c') diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 5d06384c2cae..78b6293bd04d 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1234,9 +1234,10 @@ static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file, if (err) goto err_unlock; - err = -ENODEV; - if (!fiq->connected) + if (!fiq->connected) { + err = (fc->aborted && fc->abort_err) ? -ECONNABORTED : -ENODEV; goto err_unlock; + } if (!list_empty(&fiq->interrupts)) { req = list_entry(fiq->interrupts.next, struct fuse_req, @@ -1287,7 +1288,7 @@ static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file, spin_lock(&fpq->lock); clear_bit(FR_LOCKED, &req->flags); if (!fpq->connected) { - err = -ENODEV; + err = (fc->aborted && fc->abort_err) ? -ECONNABORTED : -ENODEV; goto out_end; } if (err) { @@ -2076,7 +2077,7 @@ static void end_polls(struct fuse_conn *fc) * is OK, the request will in that case be removed from the list before we touch * it. */ -void fuse_abort_conn(struct fuse_conn *fc) +void fuse_abort_conn(struct fuse_conn *fc, bool is_abort) { struct fuse_iqueue *fiq = &fc->iq; @@ -2089,6 +2090,7 @@ void fuse_abort_conn(struct fuse_conn *fc) fc->connected = 0; fc->blocked = 0; + fc->aborted = is_abort; fuse_set_initialized(fc); list_for_each_entry(fud, &fc->devices, entry) { struct fuse_pqueue *fpq = &fud->pq; @@ -2151,7 +2153,7 @@ int fuse_dev_release(struct inode *inode, struct file *file) /* Are we the last open device? */ if (atomic_dec_and_test(&fc->dev_count)) { WARN_ON(fc->iq.fasync != NULL); - fuse_abort_conn(fc); + fuse_abort_conn(fc, false); } fuse_dev_free(fud); } -- cgit v1.2.3