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authorDavid Howells <dhowells@redhat.com>2020-04-27 17:01:09 +0300
committerDavid Howells <dhowells@redhat.com>2020-06-04 17:37:57 +0300
commit6dfdf5369c9f0a47920b2f743434c90798f26cd5 (patch)
tree037656c0d187b7dbe2657311511bf86136719f1c /fs/afs
parent6ef350b1842081bef7e4879993f47f052b7007e7 (diff)
downloadlinux-6dfdf5369c9f0a47920b2f743434c90798f26cd5.tar.xz
afs: Detect cell aliases 3 - YFS Cells with a canonical cell name op
YFS Volume Location servers have an operation by which the cell name may be queried. Use this to find out what a YFS server thinks the canonical cell name should be. Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs/afs')
-rw-r--r--fs/afs/vl_alias.c58
-rw-r--r--fs/afs/vl_rotate.c4
2 files changed, 62 insertions, 0 deletions
diff --git a/fs/afs/vl_alias.c b/fs/afs/vl_alias.c
index 76bfa4dde4a4..ac7a59e951ed 100644
--- a/fs/afs/vl_alias.c
+++ b/fs/afs/vl_alias.c
@@ -268,12 +268,70 @@ is_alias:
return 1;
}
+/*
+ * Look up a VLDB record for a volume.
+ */
+static char *afs_vl_get_cell_name(struct afs_cell *cell, struct key *key)
+{
+ struct afs_vl_cursor vc;
+ char *cell_name = ERR_PTR(-EDESTADDRREQ);
+ bool skipped = false, not_skipped = false;
+ int ret;
+
+ if (!afs_begin_vlserver_operation(&vc, cell, key))
+ return ERR_PTR(-ERESTARTSYS);
+
+ while (afs_select_vlserver(&vc)) {
+ if (!test_bit(AFS_VLSERVER_FL_IS_YFS, &vc.server->flags)) {
+ vc.ac.error = -EOPNOTSUPP;
+ skipped = true;
+ continue;
+ }
+ not_skipped = true;
+ cell_name = afs_yfsvl_get_cell_name(&vc);
+ }
+
+ ret = afs_end_vlserver_operation(&vc);
+ if (skipped && !not_skipped)
+ ret = -EOPNOTSUPP;
+ return ret < 0 ? ERR_PTR(ret) : cell_name;
+}
+
+static int yfs_check_canonical_cell_name(struct afs_cell *cell, struct key *key)
+{
+ struct afs_cell *master;
+ char *cell_name;
+
+ cell_name = afs_vl_get_cell_name(cell, key);
+ if (IS_ERR(cell_name))
+ return PTR_ERR(cell_name);
+
+ if (strcmp(cell_name, cell->name) == 0) {
+ kfree(cell_name);
+ return 0;
+ }
+
+ master = afs_lookup_cell(cell->net, cell_name, strlen(cell_name),
+ NULL, false);
+ kfree(cell_name);
+ if (IS_ERR(master))
+ return PTR_ERR(master);
+
+ cell->alias_of = master; /* Transfer our ref */
+ return 1;
+}
+
static int afs_do_cell_detect_alias(struct afs_cell *cell, struct key *key)
{
struct afs_volume *root_volume;
+ int ret;
_enter("%s", cell->name);
+ ret = yfs_check_canonical_cell_name(cell, key);
+ if (ret != -EOPNOTSUPP)
+ return ret;
+
/* Try and get the root.cell volume for comparison with other cells */
root_volume = afs_sample_volume(cell, key, "root.cell", 9);
if (!IS_ERR(root_volume)) {
diff --git a/fs/afs/vl_rotate.c b/fs/afs/vl_rotate.c
index 72eacc14e6e1..f405ca8b240a 100644
--- a/fs/afs/vl_rotate.c
+++ b/fs/afs/vl_rotate.c
@@ -151,6 +151,10 @@ bool afs_select_vlserver(struct afs_vl_cursor *vc)
vc->error = error;
vc->flags |= AFS_VL_CURSOR_RETRY;
goto next_server;
+
+ case -EOPNOTSUPP:
+ _debug("notsupp");
+ goto next_server;
}
restart_from_beginning: