Return -ECONNABORTED when userspace tries to read from /dev/fuse after the fuse connection was aborted via sysfs. The patch increases FUSE_KERNEL_MINOR_VERSION. However -ECONNABORTED is always returned, regardless of the minor version sent by userspace in FUSE_INIT. Info why this patch might be useful: https://github.com/libfuse/libfuse/issues/122 Signed-off-by: Szymon Lukasz <noh4hss@xxxxxxxxx> --- fs/fuse/control.c | 2 +- fs/fuse/dev.c | 13 ++++++++----- fs/fuse/fuse_i.h | 8 +++++++- fs/fuse/inode.c | 4 ++-- include/uapi/linux/fuse.h | 5 ++++- 5 files changed, 22 insertions(+), 10 deletions(-) diff --git a/fs/fuse/control.c b/fs/fuse/control.c index b9ea99c5b5b3..eeda05a7c882 100644 --- a/fs/fuse/control.c +++ b/fs/fuse/control.c @@ -35,7 +35,7 @@ static ssize_t fuse_conn_abort_write(struct file *file, const char __user *buf, { struct fuse_conn *fc = fuse_ctl_file_conn_get(file); if (fc) { - fuse_abort_conn(fc); + fuse_abort_conn(fc, 1); fuse_conn_put(fc); } return count; diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 13c65dd2d37d..b51da52b92b9 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 = fiq->aborted ? -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 = fpq->aborted ? -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, int is_abort) { struct fuse_iqueue *fiq = &fc->iq; @@ -2095,6 +2096,7 @@ void fuse_abort_conn(struct fuse_conn *fc) spin_lock(&fpq->lock); fpq->connected = 0; + fpq->aborted = is_abort; list_for_each_entry_safe(req, next, &fpq->io, list) { req->out.h.error = -ECONNABORTED; spin_lock(&req->waitq.lock); @@ -2113,6 +2115,7 @@ void fuse_abort_conn(struct fuse_conn *fc) spin_lock(&fiq->waitq.lock); fiq->connected = 0; + fiq->aborted = is_abort; list_splice_init(&fiq->pending, &to_end2); list_for_each_entry(req, &to_end2, list) clear_bit(FR_PENDING, &req->flags); @@ -2151,7 +2154,7 @@ 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, 0); } fuse_dev_free(fud); } diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index d5773ca67ad2..650e72be4174 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -387,6 +387,9 @@ struct fuse_iqueue { /** Connection established */ unsigned connected; + /** Connection aborted via sysfs */ + int aborted; + /** Readers of the connection are waiting on this */ wait_queue_head_t waitq; @@ -414,6 +417,9 @@ struct fuse_pqueue { /** Connection established */ unsigned connected; + /** Connection aborted via sysfs */ + int aborted; + /** Lock protecting accessess to members of this structure */ spinlock_t lock; @@ -851,7 +857,7 @@ void fuse_request_send_background_locked(struct fuse_conn *fc, struct fuse_req *req); /* Abort all requests */ -void fuse_abort_conn(struct fuse_conn *fc); +void fuse_abort_conn(struct fuse_conn *fc, int is_abort); /** * Invalidate inode attributes diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 94a745acaef8..8cc9de4ec16d 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -371,7 +371,7 @@ void fuse_unlock_inode(struct inode *inode) static void fuse_umount_begin(struct super_block *sb) { - fuse_abort_conn(get_fuse_conn_super(sb)); + fuse_abort_conn(get_fuse_conn_super(sb), 0); } static void fuse_send_destroy(struct fuse_conn *fc) @@ -393,7 +393,7 @@ static void fuse_put_super(struct super_block *sb) fuse_send_destroy(fc); - fuse_abort_conn(fc); + fuse_abort_conn(fc, 0); mutex_lock(&fuse_mutex); list_del(&fc->entry); fuse_ctl_remove_conn(fc); diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index 42fa977e3b14..4025a5599b2b 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -112,6 +112,9 @@ * 7.26 * - add FUSE_HANDLE_KILLPRIV * - add FUSE_POSIX_ACL + * + * 7.27 + * - reading from /dev/fuse after sysfs abort returns -ECONNABORTED */ #ifndef _LINUX_FUSE_H @@ -147,7 +150,7 @@ #define FUSE_KERNEL_VERSION 7 /** Minor version number of this interface */ -#define FUSE_KERNEL_MINOR_VERSION 26 +#define FUSE_KERNEL_MINOR_VERSION 27 /** The node ID of the root inode */ #define FUSE_ROOT_ID 1 -- 2.15.0
