diff options
| author | Andrew Gallagher <agallagher@fb.com> | 2013-11-05 19:05:52 +0400 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@suse.cz> | 2014-01-22 22:36:59 +0400 |
| commit | 7678ac50615d9c7a491d9861e020e4f5f71b594c (patch) | |
| tree | 0625a52697800b032fd60b652833cf0ba04e43ae /fs | |
| parent | 451418fc928b5ec1ee96a9afac807b6312811a2a (diff) | |
| download | linux-7678ac50615d9c7a491d9861e020e4f5f71b594c.tar.xz | |
fuse: support clients that don't implement 'open'
open/release operations require userspace transitions to keep track
of the open count and to perform any FS-specific setup. However,
for some purely read-only FSs which don't need to perform any setup
at open/release time, we can avoid the performance overhead of
calling into userspace for open/release calls.
This patch adds the necessary support to the fuse kernel modules to prevent
open/release operations from hitting in userspace. When the client returns
ENOSYS, we avoid sending the subsequent release to userspace, and also
remember this so that future opens also don't trigger a userspace
operation.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/fuse/file.c | 37 | ||||
| -rw-r--r-- | fs/fuse/fuse_i.h | 3 |
2 files changed, 30 insertions, 10 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index d53af8f15236..74f6ca500504 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -127,7 +127,15 @@ static void fuse_file_put(struct fuse_file *ff, bool sync) if (atomic_dec_and_test(&ff->count)) { struct fuse_req *req = ff->reserved_req; - if (sync) { + if (ff->fc->no_open) { + /* + * Drop the release request when client does not + * implement 'open' + */ + req->background = 0; + path_put(&req->misc.release.path); + fuse_put_request(ff->fc, req); + } else if (sync) { req->background = 0; fuse_request_send(ff->fc, req); path_put(&req->misc.release.path); @@ -144,27 +152,36 @@ static void fuse_file_put(struct fuse_file *ff, bool sync) int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file, bool isdir) { - struct fuse_open_out outarg; struct fuse_file *ff; - int err; int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN; ff = fuse_file_alloc(fc); if (!ff) return -ENOMEM; - err = fuse_send_open(fc, nodeid, file, opcode, &outarg); - if (err) { - fuse_file_free(ff); - return err; + ff->fh = 0; + ff->open_flags = FOPEN_KEEP_CACHE; /* Default for no-open */ + if (!fc->no_open || isdir) { + struct fuse_open_out outarg; + int err; + + err = fuse_send_open(fc, nodeid, file, opcode, &outarg); + if (!err) { + ff->fh = outarg.fh; + ff->open_flags = outarg.open_flags; + + } else if (err != -ENOSYS || isdir) { + fuse_file_free(ff); + return err; + } else { + fc->no_open = 1; + } } if (isdir) - outarg.open_flags &= ~FOPEN_DIRECT_IO; + ff->open_flags &= ~FOPEN_DIRECT_IO; - ff->fh = outarg.fh; ff->nodeid = nodeid; - ff->open_flags = outarg.open_flags; file->private_data = fuse_file_get(ff); return 0; diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index dc44b9e3a0c9..2da5db2c8bdb 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -485,6 +485,9 @@ struct fuse_conn { * and hence races in setting them will not cause malfunction */ + /** Is open/release not implemented by fs? */ + unsigned no_open:1; + /** Is fsync not implemented by fs? */ unsigned no_fsync:1; |