[lxc-devel] [lxc/master] bdev: use correct overlay module name
brauner on Github
lxc-bot at linuxcontainers.org
Tue Aug 16 20:22:08 UTC 2016
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From 054213bc72c0ea0db19f359650c44a60261089ad Mon Sep 17 00:00:00 2001
From: Christian Brauner <cbrauner at suse.de>
Date: Tue, 16 Aug 2016 20:00:35 +0200
Subject: [PATCH] bdev: use correct overlay module name
- Assume that the module name is "overlay" per default and not "overlayfs".
- Assume that the overlay version we are using requires a workdir.
- When we mount an overlay filesystem and we fail with ENODEV retry once with
the module name we haven't already used.
Signed-off-by: Christian Brauner <cbrauner at suse.de>
---
src/lxc/bdev/lxcoverlay.c | 53 +++++++++++++++++++++++++++++++++--------------
1 file changed, 38 insertions(+), 15 deletions(-)
diff --git a/src/lxc/bdev/lxcoverlay.c b/src/lxc/bdev/lxcoverlay.c
index 3caadbc..ab2c1fa 100644
--- a/src/lxc/bdev/lxcoverlay.c
+++ b/src/lxc/bdev/lxcoverlay.c
@@ -39,6 +39,7 @@
lxc_log_define(lxcoverlay, lxc);
static char *ovl_name;
+static char *ovl_version[] = {"overlay", "overlayfs"};
/* defined in lxccontainer.c: needs to become common helper */
extern char *dir_new_path(char *src, const char *oldname, const char *name,
@@ -49,6 +50,9 @@ static int ovl_do_rsync(struct bdev *orig, struct bdev *new,
struct lxc_conf *conf);
static int ovl_rsync(struct rsync_data *data);
static int ovl_rsync_wrapper(void *data);
+static int ovl_remount_on_enodev(const char *lower, const char *target,
+ const char *name, unsigned long mountflags,
+ const void *options);
int ovl_clonepaths(struct bdev *orig, struct bdev *new, const char *oldname,
const char *cname, const char *oldpath, const char *lxcpath,
@@ -408,23 +412,28 @@ int ovl_mount(struct bdev *bdev)
return -1;
}
- // mount without workdir option for overlayfs before v21
- ret = mount(lower, bdev->dest, ovl_name, MS_MGC_VAL | mntflags, options);
+ /* Assume we need a workdir as we are on a overlay version >= v22. */
+ ret = ovl_remount_on_enodev(lower, bdev->dest, ovl_name,
+ MS_MGC_VAL | mntflags, options_work);
if (ret < 0) {
- INFO("overlayfs: error mounting %s onto %s options %s. retry with workdir",
- lower, bdev->dest, options);
+ INFO("Overlayfs: Error mounting %s onto %s with options %s. "
+ "Retrying without workdir: %s.",
+ lower, bdev->dest, options, strerror(errno));
- // retry with workdir option for overlayfs v22 and higher
- ret = mount(lower, bdev->dest, ovl_name, MS_MGC_VAL | mntflags, options_work);
+ /* Assume we cannot use a workdir as we are on a version <= v21. */
+ ret = ovl_remount_on_enodev(lower, bdev->dest, ovl_name,
+ MS_MGC_VAL | mntflags, options);
if (ret < 0)
- SYSERROR("overlayfs: error mounting %s onto %s options %s",
- lower, bdev->dest, options_work);
+ SYSERROR("Overlayfs: Error mounting %s onto %s with "
+ "options %s: %s.",
+ lower, bdev->dest, options,
+ strerror(errno));
else
- INFO("overlayfs: mounted %s onto %s options %s",
- lower, bdev->dest, options_work);
+ INFO("Overlayfs: Mounted %s onto %s with options %s.",
+ lower, bdev->dest, options);
} else {
- INFO("overlayfs: mounted %s onto %s options %s",
- lower, bdev->dest, options);
+ INFO("Overlayfs: Mounted %s onto %s with options %s.", lower,
+ bdev->dest, options_work);
}
return ret;
}
@@ -652,6 +661,20 @@ int ovl_update_abs_paths(struct lxc_conf *lxc_conf, const char *lxc_path,
return fret;
}
+static int ovl_remount_on_enodev(const char *lower, const char *target,
+ const char *name, unsigned long mountflags,
+ const void *options)
+{
+ int ret;
+ ret = mount(lower, target, ovl_name, MS_MGC_VAL | mountflags, options);
+ if (ret < 0 && errno == ENODEV) /* Try other module name. */
+ ret = mount(lower, target,
+ ovl_name == ovl_version[0] ? ovl_version[1]
+ : ovl_version[0],
+ MS_MGC_VAL | mountflags, options);
+ return ret;
+}
+
static int ovl_rsync(struct rsync_data *data)
{
int ret;
@@ -700,7 +723,7 @@ static int ovl_rsync(struct rsync_data *data)
static char *ovl_detect_name(void)
{
- char *v = "overlayfs";
+ char *v = ovl_version[0];
char *line = NULL;
size_t len = 0;
FILE *f = fopen("/proc/filesystems", "r");
@@ -708,8 +731,8 @@ static char *ovl_detect_name(void)
return v;
while (getline(&line, &len, f) != -1) {
- if (strcmp(line, "nodev\toverlay\n") == 0) {
- v = "overlay";
+ if (strcmp(line, "nodev\toverlayfs\n") == 0) {
+ v = ovl_version[1];
break;
}
}
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