Revert series: virtiofsd: Announce submounts to the guest

This reverts the following commits due to their basis on a bogus
linux kernel header update:

c93a656f7b65 ("tests/acceptance: Add virtiofs_submounts.py")
45ced7ca2f27 ("tests/acceptance/boot_linux: Accept SSH pubkey")
08dce386e77e ("virtiofsd: Announce sub-mount points")
eba8b096c17c ("virtiofsd: Store every lo_inode's parent_dev")
ede24b6be798 ("virtiofsd: Add fuse_reply_attr_with_flags()")
e2577435d343 ("virtiofsd: Add attr_flags to fuse_entry_param")
2f10415abfc5 ("virtiofsd: Announce FUSE_ATTR_FLAGS")
97d741cc96dd ("linux/fuse.h: Pull in from Linux")

Cc: Max Reitz <mreitz@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 160385090886.20017.13382256442750027666.stgit@gimli.home
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

5 files changed, 14 insertions, 133 deletions

diff --git a/tools/virtiofsd/fuse_common.h b/tools/virtiofsd/fuse_common.h
index 870544fe13..686c42c0a5 100644
--- a/tools/virtiofsd/fuse_common.h
+++ b/tools/virtiofsd/fuse_common.h
@@ -353,14 +353,6 @@ struct fuse_file_info {
 #define FUSE_CAP_NO_OPENDIR_SUPPORT (1 << 24)
 
 /**
- * Indicates that the client will provide fuse_attr.flags, and the kernel will
- * interpret it.
- *
- * This feature is enabled by default when supported by the kernel.
- */
-#define FUSE_CAP_ATTR_FLAGS (1 << 27)
-
-/**
  * Ioctl flags
  *
  * FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine
diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
index 5198f627bc..4d1ba2925d 100644
--- a/tools/virtiofsd/fuse_lowlevel.c
+++ b/tools/virtiofsd/fuse_lowlevel.c
@@ -329,8 +329,7 @@ static unsigned int calc_timeout_nsec(double t)
     }
 }
 
-static void fill_entry(struct fuse_session *se,
-                       struct fuse_entry_out *arg,
+static void fill_entry(struct fuse_entry_out *arg,
                        const struct fuse_entry_param *e)
 {
     *arg = (struct fuse_entry_out){
@@ -342,10 +341,6 @@ static void fill_entry(struct fuse_session *se,
         .attr_valid_nsec = calc_timeout_nsec(e->attr_timeout),
     };
     convert_stat(&e->attr, &arg->attr);
-
-    if (se->conn.capable & FUSE_CAP_ATTR_FLAGS) {
-        arg->attr.flags = e->attr_flags;
-    }
 }
 
 /*
@@ -370,7 +365,7 @@ size_t fuse_add_direntry_plus(fuse_req_t req, char *buf, size_t bufsize,
 
     struct fuse_direntplus *dp = (struct fuse_direntplus *)buf;
     memset(&dp->entry_out, 0, sizeof(dp->entry_out));
-    fill_entry(req->se, &dp->entry_out, e);
+    fill_entry(&dp->entry_out, e);
 
     struct fuse_dirent *dirent = &dp->dirent;
     *dirent = (struct fuse_dirent){
@@ -408,7 +403,7 @@ int fuse_reply_entry(fuse_req_t req, const struct fuse_entry_param *e)
     size_t size = sizeof(arg);
 
     memset(&arg, 0, sizeof(arg));
-    fill_entry(req->se, &arg, e);
+    fill_entry(&arg, e);
     return send_reply_ok(req, &arg, size);
 }
 
@@ -421,13 +416,13 @@ int fuse_reply_create(fuse_req_t req, const struct fuse_entry_param *e,
     struct fuse_open_out *oarg = (struct fuse_open_out *)(buf + entrysize);
 
     memset(buf, 0, sizeof(buf));
-    fill_entry(req->se, earg, e);
+    fill_entry(earg, e);
     fill_open(oarg, f);
     return send_reply_ok(req, buf, entrysize + sizeof(struct fuse_open_out));
 }
 
-int fuse_reply_attr_with_flags(fuse_req_t req, const struct stat *attr,
-                               double attr_timeout, uint32_t attr_flags)
+int fuse_reply_attr(fuse_req_t req, const struct stat *attr,
+                    double attr_timeout)
 {
     struct fuse_attr_out arg;
     size_t size = sizeof(arg);
@@ -437,19 +432,9 @@ int fuse_reply_attr_with_flags(fuse_req_t req, const struct stat *attr,
     arg.attr_valid_nsec = calc_timeout_nsec(attr_timeout);
     convert_stat(attr, &arg.attr);
 
-    if (req->se->conn.capable & FUSE_CAP_ATTR_FLAGS) {
-        arg.attr.flags = attr_flags;
-    }
-
     return send_reply_ok(req, &arg, size);
 }
 
-int fuse_reply_attr(fuse_req_t req, const struct stat *attr,
-                    double attr_timeout)
-{
-    return fuse_reply_attr_with_flags(req, attr, attr_timeout, 0);
-}
-
 int fuse_reply_readlink(fuse_req_t req, const char *linkname)
 {
     return send_reply_ok(req, linkname, strlen(linkname));
@@ -2003,9 +1988,6 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid,
             bufsize = max_bufsize;
         }
     }
-    if (arg->flags & FUSE_ATTR_FLAGS) {
-        se->conn.capable |= FUSE_CAP_ATTR_FLAGS;
-    }
 #ifdef HAVE_SPLICE
 #ifdef HAVE_VMSPLICE
     se->conn.capable |= FUSE_CAP_SPLICE_WRITE | FUSE_CAP_SPLICE_MOVE;
@@ -2032,7 +2014,6 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid,
     LL_SET_DEFAULT(1, FUSE_CAP_ASYNC_DIO);
     LL_SET_DEFAULT(1, FUSE_CAP_IOCTL_DIR);
     LL_SET_DEFAULT(1, FUSE_CAP_ATOMIC_O_TRUNC);
-    LL_SET_DEFAULT(1, FUSE_CAP_ATTR_FLAGS);
     LL_SET_DEFAULT(se->op.write_buf, FUSE_CAP_SPLICE_READ);
     LL_SET_DEFAULT(se->op.getlk && se->op.setlk, FUSE_CAP_POSIX_LOCKS);
     LL_SET_DEFAULT(se->op.flock, FUSE_CAP_FLOCK_LOCKS);
@@ -2122,9 +2103,6 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid,
     if (se->conn.want & FUSE_CAP_POSIX_ACL) {
         outarg.flags |= FUSE_POSIX_ACL;
     }
-    if (se->conn.want & FUSE_CAP_ATTR_FLAGS) {
-        outarg.flags |= FUSE_ATTR_FLAGS;
-    }
     outarg.max_readahead = se->conn.max_readahead;
     outarg.max_write = se->conn.max_write;
     if (se->conn.max_background >= (1 << 16)) {
diff --git a/tools/virtiofsd/fuse_lowlevel.h b/tools/virtiofsd/fuse_lowlevel.h
index 1ff6ba1e4f..562fd5241e 100644
--- a/tools/virtiofsd/fuse_lowlevel.h
+++ b/tools/virtiofsd/fuse_lowlevel.h
@@ -102,11 +102,6 @@ struct fuse_entry_param {
      *  large value.
      */
     double entry_timeout;
-
-    /**
-     * Flags for fuse_attr.flags that do not fit into attr.
-     */
-    uint32_t attr_flags;
 };
 
 /**
@@ -1314,21 +1309,6 @@ int fuse_reply_attr(fuse_req_t req, const struct stat *attr,
                     double attr_timeout);
 
 /**
- * Reply with attributes and set fuse_attr.flags
- *
- * Possible requests:
- *   getattr, setattr
- *
- * @param req request handle
- * @param attr the attributes
- * @param attr_timeout validity timeout (in seconds) for the attributes
- * @param attr_flags flags to put into fuse_attr.flags
- * @return zero for success, -errno for failure to send reply
- */
-int fuse_reply_attr_with_flags(fuse_req_t req, const struct stat *attr,
-                               double attr_timeout, uint32_t attr_flags);
-
-/**
  * Reply with the contents of a symbolic link
  *
  * Possible requests:
diff --git a/tools/virtiofsd/helper.c b/tools/virtiofsd/helper.c
index a212f32931..2e181a49b5 100644
--- a/tools/virtiofsd/helper.c
+++ b/tools/virtiofsd/helper.c
@@ -178,7 +178,6 @@ void fuse_cmdline_help(void)
            "                               default: depends on cache= option.\n"
            "    -o writeback|no_writeback  enable/disable writeback cache\n"
            "                               default: no_writeback\n"
-           "    -o announce_submounts      Announce sub-mount points to the guest\n"
            "    -o xattr|no_xattr          enable/disable xattr\n"
            "                               default: no_xattr\n"
            "    -o modcaps=CAPLIST         Modify the list of capabilities\n"
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index 4db50046d4..a0beb986f3 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -40,7 +40,6 @@
 #include "fuse_virtio.h"
 #include "fuse_log.h"
 #include "fuse_lowlevel.h"
-#include "standard-headers/linux/fuse.h"
 #include <assert.h>
 #include <cap-ng.h>
 #include <dirent.h>
@@ -126,14 +125,6 @@ struct lo_inode {
     GHashTable *posix_locks; /* protected by lo_inode->plock_mutex */
 
     mode_t filetype;
-
-    /*
-     * So we can detect crossmount roots
-     * (As such, this only needs to be valid for directories.  Note
-     * that files can have multiple parents due to hard links, and so
-     * their parent_dev may fluctuate.)
-     */
-    dev_t parent_dev;
 };
 
 struct lo_cred {
@@ -174,7 +165,6 @@ struct lo_data {
     int timeout_set;
     int readdirplus_set;
     int readdirplus_clear;
-    int announce_submounts;
     int allow_direct_io;
     struct lo_inode root;
     GHashTable *inodes; /* protected by lo->mutex */
@@ -213,7 +203,6 @@ static const struct fuse_opt lo_opts[] = {
     { "cache=always", offsetof(struct lo_data, cache), CACHE_ALWAYS },
     { "readdirplus", offsetof(struct lo_data, readdirplus_set), 1 },
     { "no_readdirplus", offsetof(struct lo_data, readdirplus_clear), 1 },
-    { "announce_submounts", offsetof(struct lo_data, announce_submounts), 1 },
     { "allow_direct_io", offsetof(struct lo_data, allow_direct_io), 1 },
     { "no_allow_direct_io", offsetof(struct lo_data, allow_direct_io), 0 },
     FUSE_OPT_END
@@ -611,52 +600,22 @@ static void lo_init(void *userdata, struct fuse_conn_info *conn)
     }
 }
 
-/**
- * Call fstatat() and set st_rdev whenever a directory's st_dev
- * differs from the rparent's st_dev (@parent_dev).  This will
- * announce submounts to the FUSE client (unless @announce_submounts
- * is false).
- */
-static int do_fstatat(int dirfd, const char *pathname, struct stat *statbuf,
-                      int flags, dev_t parent_dev, uint32_t *fuse_attr_flags)
-{
-    int res = fstatat(dirfd, pathname, statbuf, flags);
-    if (res == -1) {
-        return res;
-    }
-
-    if (statbuf->st_dev != parent_dev && S_ISDIR(statbuf->st_mode) &&
-        fuse_attr_flags)
-    {
-        *fuse_attr_flags |= FUSE_ATTR_SUBMOUNT;
-    }
-
-    return 0;
-}
-
 static void lo_getattr(fuse_req_t req, fuse_ino_t ino,
                        struct fuse_file_info *fi)
 {
     int res;
     struct stat buf;
     struct lo_data *lo = lo_data(req);
-    struct lo_inode *inode = lo_inode(req, ino);
-    uint32_t fuse_attr_flags = 0;
 
     (void)fi;
 
-    res = do_fstatat(inode->fd, "", &buf, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW,
-                     inode->parent_dev, &fuse_attr_flags);
-    lo_inode_put(lo, &inode);
+    res =
+        fstatat(lo_fd(req, ino), "", &buf, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
     if (res == -1) {
         return (void)fuse_reply_err(req, errno);
     }
 
-    if (!lo->announce_submounts) {
-        fuse_attr_flags &= ~FUSE_ATTR_SUBMOUNT;
-    }
-
-    fuse_reply_attr_with_flags(req, &buf, lo->timeout, fuse_attr_flags);
+    fuse_reply_attr(req, &buf, lo->timeout);
 }
 
 static int lo_fi_fd(fuse_req_t req, struct fuse_file_info *fi)
@@ -852,16 +811,11 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
         goto out_err;
     }
 
-    res = do_fstatat(newfd, "", &e->attr, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW,
-                     dir->key.dev, &e->attr_flags);
+    res = fstatat(newfd, "", &e->attr, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
     if (res == -1) {
         goto out_err;
     }
 
-    if (!lo->announce_submounts) {
-        e->attr_flags &= ~FUSE_ATTR_SUBMOUNT;
-    }
-
     inode = lo_find(lo, &e->attr);
     if (inode) {
         close(newfd);
@@ -893,7 +847,6 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
         g_hash_table_insert(lo->inodes, &inode->key, inode);
         pthread_mutex_unlock(&lo->mutex);
     }
-    inode->parent_dev = dir->key.dev;
     e->ino = inode->fuse_ino;
     lo_inode_put(lo, &inode);
     lo_inode_put(lo, &dir);
@@ -1107,17 +1060,11 @@ static void lo_link(fuse_req_t req, fuse_ino_t ino, fuse_ino_t parent,
         goto out_err;
     }
 
-    res = do_fstatat(inode->fd, "", &e.attr,
-                     AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW,
-                     parent_inode->key.dev, &e.attr_flags);
+    res = fstatat(inode->fd, "", &e.attr, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
     if (res == -1) {
         goto out_err;
     }
 
-    if (!lo->announce_submounts) {
-        e.attr_flags &= ~FUSE_ATTR_SUBMOUNT;
-    }
-
     pthread_mutex_lock(&lo->mutex);
     inode->nlookup++;
     pthread_mutex_unlock(&lo->mutex);
@@ -1126,14 +1073,6 @@ static void lo_link(fuse_req_t req, fuse_ino_t ino, fuse_ino_t parent,
     fuse_log(FUSE_LOG_DEBUG, "  %lli/%s -> %lli\n", (unsigned long long)parent,
              name, (unsigned long long)e.ino);
 
-    /*
-     * No need to update inode->parent_dev, because
-     * (1) We cannot, the inode now has more than one parent,
-     * (2) Directories cannot have more than one parent, so link()
-     *     does not work for them; but parent_dev only needs to be
-     *     valid for directories.
-     */
-
     fuse_reply_entry(req, &e);
     lo_inode_put(lo, &parent_inode);
     lo_inode_put(lo, &inode);
@@ -1152,21 +1091,14 @@ static struct lo_inode *lookup_name(fuse_req_t req, fuse_ino_t parent,
 {
     int res;
     struct stat attr;
-    struct lo_data *lo = lo_data(req);
-    struct lo_inode *dir = lo_inode(req, parent);
 
-    if (!dir) {
-        return NULL;
-    }
-
-    res = do_fstatat(dir->fd, name, &attr,
-                     AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW, dir->key.dev, NULL);
-    lo_inode_put(lo, &dir);
+    res = fstatat(lo_fd(req, parent), name, &attr,
+                  AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
     if (res == -1) {
         return NULL;
     }
 
-    return lo_find(lo, &attr);
+    return lo_find(lo_data(req), &attr);
 }
 
 static void lo_rmdir(fuse_req_t req, fuse_ino_t parent, const char *name)