diff options
Diffstat (limited to 'fs/fuse/iomode.c')
| -rw-r--r-- | fs/fuse/iomode.c | 60 |
1 files changed, 54 insertions, 6 deletions
diff --git a/fs/fuse/iomode.c b/fs/fuse/iomode.c index 2161bdf91db2..c653ddcf0578 100644 --- a/fs/fuse/iomode.c +++ b/fs/fuse/iomode.c @@ -17,7 +17,7 @@ */ static inline bool fuse_is_io_cache_wait(struct fuse_inode *fi) { - return READ_ONCE(fi->iocachectr) < 0; + return READ_ONCE(fi->iocachectr) < 0 && !fuse_inode_backing(fi); } /* @@ -45,6 +45,17 @@ int fuse_file_cached_io_start(struct inode *inode, struct fuse_file *ff) wait_event(fi->direct_io_waitq, !fuse_is_io_cache_wait(fi)); spin_lock(&fi->lock); } + + /* + * Check if inode entered passthrough io mode while waiting for parallel + * dio write completion. + */ + if (fuse_inode_backing(fi)) { + clear_bit(FUSE_I_CACHE_IO_MODE, &fi->state); + spin_unlock(&fi->lock); + return -ETXTBSY; + } + WARN_ON(ff->iomode == IOM_UNCACHED); if (ff->iomode == IOM_NONE) { ff->iomode = IOM_CACHED; @@ -71,12 +82,19 @@ static void fuse_file_cached_io_end(struct inode *inode, struct fuse_file *ff) } /* Start strictly uncached io mode where cache access is not allowed */ -int fuse_file_uncached_io_start(struct inode *inode, struct fuse_file *ff) +int fuse_file_uncached_io_start(struct inode *inode, struct fuse_file *ff, struct fuse_backing *fb) { struct fuse_inode *fi = get_fuse_inode(inode); + struct fuse_backing *oldfb; int err = 0; spin_lock(&fi->lock); + /* deny conflicting backing files on same fuse inode */ + oldfb = fuse_inode_backing(fi); + if (oldfb && oldfb != fb) { + err = -EBUSY; + goto unlock; + } if (fi->iocachectr > 0) { err = -ETXTBSY; goto unlock; @@ -84,6 +102,14 @@ int fuse_file_uncached_io_start(struct inode *inode, struct fuse_file *ff) WARN_ON(ff->iomode != IOM_NONE); fi->iocachectr--; ff->iomode = IOM_UNCACHED; + + /* fuse inode holds a single refcount of backing file */ + if (!oldfb) { + oldfb = fuse_inode_backing_set(fi, fb); + WARN_ON_ONCE(oldfb != NULL); + } else { + fuse_backing_put(fb); + } unlock: spin_unlock(&fi->lock); return err; @@ -92,15 +118,20 @@ unlock: void fuse_file_uncached_io_end(struct inode *inode, struct fuse_file *ff) { struct fuse_inode *fi = get_fuse_inode(inode); + struct fuse_backing *oldfb = NULL; spin_lock(&fi->lock); WARN_ON(fi->iocachectr >= 0); WARN_ON(ff->iomode != IOM_UNCACHED); ff->iomode = IOM_NONE; fi->iocachectr++; - if (!fi->iocachectr) + if (!fi->iocachectr) { wake_up(&fi->direct_io_waitq); + oldfb = fuse_inode_backing_set(fi, NULL); + } spin_unlock(&fi->lock); + if (oldfb) + fuse_backing_put(oldfb); } /* @@ -118,6 +149,7 @@ static int fuse_file_passthrough_open(struct inode *inode, struct file *file) { struct fuse_file *ff = file->private_data; struct fuse_conn *fc = get_fuse_conn(inode); + struct fuse_backing *fb; int err; /* Check allowed conditions for file open in passthrough mode */ @@ -125,11 +157,18 @@ static int fuse_file_passthrough_open(struct inode *inode, struct file *file) (ff->open_flags & ~FOPEN_PASSTHROUGH_MASK)) return -EINVAL; - /* TODO: implement backing file open */ - return -EOPNOTSUPP; + fb = fuse_passthrough_open(file, inode, + ff->args->open_outarg.backing_id); + if (IS_ERR(fb)) + return PTR_ERR(fb); /* First passthrough file open denies caching inode io mode */ - err = fuse_file_uncached_io_start(inode, ff); + err = fuse_file_uncached_io_start(inode, ff, fb); + if (!err) + return 0; + + fuse_passthrough_release(ff, fb); + fuse_backing_put(fb); return err; } @@ -138,6 +177,7 @@ static int fuse_file_passthrough_open(struct inode *inode, struct file *file) int fuse_file_io_open(struct file *file, struct inode *inode) { struct fuse_file *ff = file->private_data; + struct fuse_inode *fi = get_fuse_inode(inode); int err; /* @@ -148,6 +188,14 @@ int fuse_file_io_open(struct file *file, struct inode *inode) return 0; /* + * Server is expected to use FOPEN_PASSTHROUGH for all opens of an inode + * which is already open for passthrough. + */ + err = -EINVAL; + if (fuse_inode_backing(fi) && !(ff->open_flags & FOPEN_PASSTHROUGH)) + goto fail; + + /* * FOPEN_PARALLEL_DIRECT_WRITES requires FOPEN_DIRECT_IO. */ if (!(ff->open_flags & FOPEN_DIRECT_IO)) |