From 775c5033a0d164622d9d10dd0f0a5531639ed3ed Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Thu, 4 Mar 2021 11:09:12 +0200 Subject: [PATCH 1/3] fuse: fix live lock in fuse_iget() Commit 5d069dbe8aaf ("fuse: fix bad inode") replaced make_bad_inode() in fuse_iget() with a private implementation fuse_make_bad(). The private implementation fails to remove the bad inode from inode cache, so the retry loop with iget5_locked() finds the same bad inode and marks it bad forever. kmsg snip: [ ] rcu: INFO: rcu_sched self-detected stall on CPU ... [ ] ? bit_wait_io+0x50/0x50 [ ] ? fuse_init_file_inode+0x70/0x70 [ ] ? find_inode.isra.32+0x60/0xb0 [ ] ? fuse_init_file_inode+0x70/0x70 [ ] ilookup5_nowait+0x65/0x90 [ ] ? fuse_init_file_inode+0x70/0x70 [ ] ilookup5.part.36+0x2e/0x80 [ ] ? fuse_init_file_inode+0x70/0x70 [ ] ? fuse_inode_eq+0x20/0x20 [ ] iget5_locked+0x21/0x80 [ ] ? fuse_inode_eq+0x20/0x20 [ ] fuse_iget+0x96/0x1b0 Fixes: 5d069dbe8aaf ("fuse: fix bad inode") Cc: stable@vger.kernel.org # 5.10+ Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi --- fs/fuse/fuse_i.h | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 68cca8d4db6ed5..63d97a15ffde97 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -863,6 +863,7 @@ static inline u64 fuse_get_attr_version(struct fuse_conn *fc) static inline void fuse_make_bad(struct inode *inode) { + remove_inode_hash(inode); set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state); } From 3f9b9efd82a84f27e95d0414f852caf1fa839e83 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Tue, 9 Feb 2021 17:47:54 -0500 Subject: [PATCH 2/3] virtiofs: Fail dax mount if device does not support it Right now "mount -t virtiofs -o dax myfs /mnt/virtiofs" succeeds even if filesystem deivce does not have a cache window and hence DAX can't be supported. This gives a false sense to user that they are using DAX with virtiofs but fact of the matter is that they are not. Fix this by returning error if dax can't be supported and user has asked for it. Signed-off-by: Vivek Goyal Reviewed-by: Stefan Hajnoczi Signed-off-by: Miklos Szeredi --- fs/fuse/virtio_fs.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c index 8868ac31a3c0a1..4ee6f734ba8380 100644 --- a/fs/fuse/virtio_fs.c +++ b/fs/fuse/virtio_fs.c @@ -1324,8 +1324,15 @@ static int virtio_fs_fill_super(struct super_block *sb, struct fs_context *fsc) /* virtiofs allocates and installs its own fuse devices */ ctx->fudptr = NULL; - if (ctx->dax) + if (ctx->dax) { + if (!fs->dax_dev) { + err = -EINVAL; + pr_err("virtio-fs: dax can't be enabled as filesystem" + " device does not support it.\n"); + goto err_free_fuse_devs; + } ctx->dax_dev = fs->dax_dev; + } err = fuse_fill_super_common(sb, ctx); if (err < 0) goto err_free_fuse_devs; From f8425c9396639cc462bcce44b1051f8b4e62fddb Mon Sep 17 00:00:00 2001 From: Alessio Balsini Date: Mon, 25 Jan 2021 15:30:51 +0000 Subject: [PATCH 3/3] fuse: 32-bit user space ioctl compat for fuse device With a 64-bit kernel build the FUSE device cannot handle ioctl requests coming from 32-bit user space. This is due to the ioctl command translation that generates different command identifiers that thus cannot be used for direct comparisons without proper manipulation. Explicitly extract type and number from the ioctl command to enable 32-bit user space compatibility on 64-bit kernel builds. Signed-off-by: Alessio Balsini Signed-off-by: Miklos Szeredi --- fs/fuse/dev.c | 26 ++++++++++++++++---------- include/uapi/linux/fuse.h | 3 ++- 2 files changed, 18 insertions(+), 11 deletions(-) diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index c6636b4c4ccf25..c0fee830a34eda 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -2229,19 +2229,21 @@ static int fuse_device_clone(struct fuse_conn *fc, struct file *new) static long fuse_dev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { - int err = -ENOTTY; + int res; + int oldfd; + struct fuse_dev *fud = NULL; - if (cmd == FUSE_DEV_IOC_CLONE) { - int oldfd; + if (_IOC_TYPE(cmd) != FUSE_DEV_IOC_MAGIC) + return -ENOTTY; - err = -EFAULT; - if (!get_user(oldfd, (__u32 __user *) arg)) { + switch (_IOC_NR(cmd)) { + case _IOC_NR(FUSE_DEV_IOC_CLONE): + res = -EFAULT; + if (!get_user(oldfd, (__u32 __user *)arg)) { struct file *old = fget(oldfd); - err = -EINVAL; + res = -EINVAL; if (old) { - struct fuse_dev *fud = NULL; - /* * Check against file->f_op because CUSE * uses the same ioctl handler. @@ -2252,14 +2254,18 @@ static long fuse_dev_ioctl(struct file *file, unsigned int cmd, if (fud) { mutex_lock(&fuse_mutex); - err = fuse_device_clone(fud->fc, file); + res = fuse_device_clone(fud->fc, file); mutex_unlock(&fuse_mutex); } fput(old); } } + break; + default: + res = -ENOTTY; + break; } - return err; + return res; } const struct file_operations fuse_dev_operations = { diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index 98ca64d1beb6fb..54442612c48bd7 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -903,7 +903,8 @@ struct fuse_notify_retrieve_in { }; /* Device ioctls: */ -#define FUSE_DEV_IOC_CLONE _IOR(229, 0, uint32_t) +#define FUSE_DEV_IOC_MAGIC 229 +#define FUSE_DEV_IOC_CLONE _IOR(FUSE_DEV_IOC_MAGIC, 0, uint32_t) struct fuse_lseek_in { uint64_t fh;