diff options
| -rw-r--r-- | example/passthrough_hp.cc | 4 | ||||
| -rw-r--r-- | include/fuse_common.h | 9 | ||||
| -rw-r--r-- | lib/fuse_lowlevel.c | 4 |
3 files changed, 17 insertions, 0 deletions
diff --git a/example/passthrough_hp.cc b/example/passthrough_hp.cc index 96201d6..66fe6f8 100644 --- a/example/passthrough_hp.cc +++ b/example/passthrough_hp.cc @@ -212,6 +212,10 @@ static void sfs_init(void *userdata, fuse_conn_info *conn) { if (conn->capable & FUSE_CAP_SPLICE_READ) conn->want |= FUSE_CAP_SPLICE_READ; } + + /* This is a local file system - no network coherency needed */ + if (conn->capable & FUSE_CAP_DIRECT_IO_ALLOW_MMAP) + conn->want |= FUSE_CAP_DIRECT_IO_ALLOW_MMAP; } diff --git a/include/fuse_common.h b/include/fuse_common.h index 3ff14ec..a804134 100644 --- a/include/fuse_common.h +++ b/include/fuse_common.h @@ -441,6 +441,15 @@ struct fuse_loop_config_v1 { #define FUSE_CAP_SETXATTR_EXT (1 << 27) /** + * Files opened with FUSE_DIRECT_IO do not support MAP_SHARED mmap. This restriction + * is relaxed through FUSE_CAP_DIRECT_IO_RELAX (kernel flag: FUSE_DIRECT_IO_RELAX). + * MAP_SHARED is disabled by default for FUSE_DIRECT_IO, as this flag can be used to + * ensure coherency between mount points (or network clients) and with kernel page + * cache as enforced by mmap that cannot be guaranteed anymore. + */ +#define FUSE_CAP_DIRECT_IO_ALLOW_MMAP (1 << 27) + +/** * Ioctl flags * * FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c index ea98536..41e626b 100644 --- a/lib/fuse_lowlevel.c +++ b/lib/fuse_lowlevel.c @@ -2019,6 +2019,8 @@ void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg) bufsize = max_bufsize; } } + if (inargflags & FUSE_DIRECT_IO_ALLOW_MMAP) + se->conn.capable |= FUSE_CAP_DIRECT_IO_ALLOW_MMAP; if (arg->minor >= 38) se->conn.capable |= FUSE_CAP_EXPIRE_ONLY; } else { @@ -2151,6 +2153,8 @@ void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg) outargflags |= FUSE_EXPLICIT_INVAL_DATA; if (se->conn.want & FUSE_CAP_SETXATTR_EXT) outargflags |= FUSE_SETXATTR_EXT; + if (se->conn.want & FUSE_CAP_DIRECT_IO_ALLOW_MMAP) + outargflags |= FUSE_DIRECT_IO_ALLOW_MMAP; if (inargflags & FUSE_INIT_EXT) { outargflags |= FUSE_INIT_EXT; |