This is the case e.g. if JFFS2 partition is full. see: https://www.mail-archive.com/linux-unionfs@vger.kernel.org/msg00246.html (a small error in a logmessage was changed and reported upstream)
runtime tested on ar71xx with kernel 3.18.11 and r45772 this paritially fixes #19564 Signed-off-by: Thomas Huehn <tho...@net.t-labs.tu-berlin.de> Signed-off-by: Bastian Bittorf <bitt...@bluebottle.com> --- ...-overlayfs-fallback-to-readonly-when-full.patch | 73 ++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 target/linux/generic/patches-3.18/912-overlayfs-fallback-to-readonly-when-full.patch diff --git a/target/linux/generic/patches-3.18/912-overlayfs-fallback-to-readonly-when-full.patch b/target/linux/generic/patches-3.18/912-overlayfs-fallback-to-readonly-when-full.patch new file mode 100644 index 0000000..9e5fad4 --- /dev/null +++ b/target/linux/generic/patches-3.18/912-overlayfs-fallback-to-readonly-when-full.patch @@ -0,0 +1,73 @@ +Index: linux-3.18.14/fs/overlayfs/copy_up.c +=================================================================== +--- linux-3.18.14.orig/fs/overlayfs/copy_up.c 2015-05-20 17:04:50.000000000 +0200 ++++ linux-3.18.14/fs/overlayfs/copy_up.c 2015-05-29 13:58:51.281147554 +0200 +@@ -300,6 +300,9 @@ + struct cred *override_cred; + char *link = NULL; + ++ if (WARN_ON(!workdir)) ++ return -EROFS; ++ + ovl_path_upper(parent, &parentpath); + upperdir = parentpath.dentry; + +Index: linux-3.18.14/fs/overlayfs/dir.c +=================================================================== +--- linux-3.18.14.orig/fs/overlayfs/dir.c 2015-05-20 17:04:50.000000000 +0200 ++++ linux-3.18.14/fs/overlayfs/dir.c 2015-05-29 14:00:55.727646504 +0200 +@@ -222,6 +222,9 @@ + struct kstat stat; + int err; + ++ if (WARN_ON(!workdir)) ++ return ERR_PTR(-EROFS); ++ + err = ovl_lock_rename_workdir(workdir, upperdir); + if (err) + goto out; +@@ -322,6 +325,9 @@ + struct dentry *newdentry; + int err; + ++ if (WARN_ON(!workdir)) ++ return -EROFS; ++ + err = ovl_lock_rename_workdir(workdir, upperdir); + if (err) + goto out; +@@ -506,6 +512,9 @@ + struct dentry *opaquedir = NULL; + int err; + ++ if (WARN_ON(!workdir)) ++ return -EROFS; ++ + if (is_dir) { + opaquedir = ovl_check_empty_and_clear(dentry); + err = PTR_ERR(opaquedir); +Index: linux-3.18.14/fs/overlayfs/super.c +=================================================================== +--- linux-3.18.14.orig/fs/overlayfs/super.c 2015-05-20 17:04:50.000000000 +0200 ++++ linux-3.18.14/fs/overlayfs/super.c 2015-05-29 14:05:45.901472157 +0200 +@@ -740,9 +740,17 @@ + ufs->workdir = ovl_workdir_create(ufs->upper_mnt, workpath.dentry); + err = PTR_ERR(ufs->workdir); + if (IS_ERR(ufs->workdir)) { +- pr_err("overlayfs: failed to create directory %s/%s\n", +- ufs->config.workdir, OVL_WORKDIR_NAME); +- goto out_put_lower_mnt; ++ if (err == -ENOSPC || err == -EROFS) { ++ pr_warning("overlayfs: failed to create work directory" ++ " (%s), mounting read-only\n", ++ err == ENOSPC ? "ENOSPC" : "EROFS"); ++ sb->s_flags |= MS_RDONLY; ++ ufs->workdir = NULL; ++ } else { ++ pr_err("overlayfs: failed to create directory %s/%s\n", ++ ufs->config.workdir, OVL_WORKDIR_NAME); ++ goto out_put_lower_mnt; ++ } + } + + /* -- 2.4.0 _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel