On 05/27/2015 06:58 PM, Bastian Bittorf wrote: > 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: Bastian Bittorf <bitt...@bluebottle.com>
Acked-by: Jo-Philipp Wich <j...@openwrt.org> > --- > ...-overlayfs-fallback-to-readonly-when-full.patch | 109 > ++++++++++++++++++++ > 1 file changed, 109 insertions(+) > create mode 100644 > target/linux/ar71xx/patches-3.18/910-overlayfs-fallback-to-readonly-when-full.patch > > diff --git > a/target/linux/ar71xx/patches-3.18/910-overlayfs-fallback-to-readonly-when-full.patch > > b/target/linux/ar71xx/patches-3.18/910-overlayfs-fallback-to-readonly-when-full.patch > new file mode 100644 > index 0000000..21f11fd > --- /dev/null > +++ > b/target/linux/ar71xx/patches-3.18/910-overlayfs-fallback-to-readonly-when-full.patch > @@ -0,0 +1,109 @@ > +[linux-unionfs added to Cc] > + > +On Tue, May 19, 2015 at 09:51:20AM +0200, Bastian Bittorf wrote: > +> Hi Miklos, > +> > +> sorry for writing directly to you, feel free to forward > +> this to the appropriate mailinglist. > +> > +> we have a problem with mainline overlay filesystem on kernel 3.18: > +> https://dev.openwrt.org/ticket/19564 > +> > +> 2 things are odd: > +> when the working filesystem is full, overlays fails with: > +> > +> overlayfs: failed to create directory /overlay/work/work > +> > +> what is strange, that we call it with: > +> > +> mount(overlay, "/mnt", "overlay", MS_NOATIME, lowerdir) > +> > +> see here: > +> > http://nbd.name/gitweb.cgi?p=fstools.git;a=blob;f=libfstools/mount.c;h=81176ce399b4cd8e2d347c0008c13dec92407f55;hb=e6004000ff15d7bd32cf5663e8690fc94d7ec747#l125 > +> > +> do you have an idea whats wrong? > +> 1) is it really needed, that we need space for creating dir > "/overlay/work"? > +> 2) why does overlay need "/overlay/work/work"? > + > +The work directory is needed for atomic copy-up and similar. It is not > actually > +necessary to mount a read-only overlay. Post 4.0 it is possible to mount the > +overlay without workdir (but even then it won't happen automatically in case > the > +upper fs is full, so this should be fixed in the latest kernel too). > + > +Could you please try the following patch? If the workdir can't be created it > +will fall back to mounting the overlay read-only. > + > +Thanks, > +Miklos > + > +--- > + fs/overlayfs/copy_up.c | 3 +++ > + fs/overlayfs/dir.c | 9 +++++++++ > + fs/overlayfs/super.c | 12 +++++++++--- > + 3 files changed, 21 insertions(+), 3 deletions(-) > + > +--- a/fs/overlayfs/copy_up.c > ++++ b/fs/overlayfs/copy_up.c > +@@ -300,6 +300,9 @@ int ovl_copy_up_one(struct dentry *paren > + struct cred *override_cred; > + char *link = NULL; > + > ++ if (WARN_ON(!workdir)) > ++ return -EROFS; > ++ > + ovl_path_upper(parent, &parentpath); > + upperdir = parentpath.dentry; > + > +--- a/fs/overlayfs/dir.c > ++++ b/fs/overlayfs/dir.c > +@@ -222,6 +222,9 @@ static struct dentry *ovl_clear_empty(st > + 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 @@ static int ovl_create_over_whiteout(stru > + 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 @@ static int ovl_remove_and_whiteout(struc > + 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); > +--- a/fs/overlayfs/super.c > ++++ b/fs/overlayfs/super.c > +@@ -740,9 +740,15 @@ static int ovl_fill_super(struct super_b > + 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; > ++ } > + } > + > + /* > _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
