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	Changelogs: * https://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.18.15 * https://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.18.16 Signed-off-by: Jonas Gorski <jogo@openwrt.org> SVN-Revision: 46011
		
			
				
	
	
		
			110 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			110 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| [linux-unionfs added to Cc]
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| 
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| On Tue, May 19, 2015 at 09:51:20AM +0200, Bastian Bittorf wrote:
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| > Hi Miklos,
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| >
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| > sorry for writing directly to you, feel free to forward
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| > this to the appropriate mailinglist.
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| >
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| > we have a problem with mainline overlay filesystem on kernel 3.18:
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| > https://dev.openwrt.org/ticket/19564
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| >
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| > 2 things are odd:
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| > when the working filesystem is full, overlays fails with:
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| >
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| > overlayfs: failed to create directory /overlay/work/work
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| >
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| > what is strange, that we call it with:
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| >
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| > mount(overlay, "/mnt", "overlay", MS_NOATIME, lowerdir)
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| >
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| > see here:
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| > http://nbd.name/gitweb.cgi?p=fstools.git;a=blob;f=libfstools/mount.c;h=81176ce399b4cd8e2d347c0008c13dec92407f55;hb=e6004000ff15d7bd32cf5663e8690fc94d7ec747#l125
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| >
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| > do you have an idea whats wrong?
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| > 1) is it really needed, that we need space for creating dir "/overlay/work"?
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| > 2) why does overlay need "/overlay/work/work"?
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| 
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| The work directory is needed for atomic copy-up and similar.  It is not actually
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| necessary to mount a read-only overlay.  Post 4.0 it is possible to mount the
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| overlay without workdir (but even then it won't happen automatically in case the
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| upper fs is full, so this should be fixed in the latest kernel too).
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| 
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| Could you please try the following patch?  If the workdir can't be created it
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| will fall back to mounting the overlay read-only.
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| 
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| Thanks,
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| Miklos
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| 
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| ---
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|  fs/overlayfs/copy_up.c |    3 +++
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|  fs/overlayfs/dir.c     |    9 +++++++++
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|  fs/overlayfs/super.c   |   12 +++++++++---
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|  3 files changed, 21 insertions(+), 3 deletions(-)
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| 
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| --- a/fs/overlayfs/copy_up.c
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| +++ b/fs/overlayfs/copy_up.c
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| @@ -300,6 +300,9 @@ int ovl_copy_up_one(struct dentry *paren
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|  	struct cred *override_cred;
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|  	char *link = NULL;
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|  
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| +	if (WARN_ON(!workdir))
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| +		return -EROFS;
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| +
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|  	ovl_path_upper(parent, &parentpath);
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|  	upperdir = parentpath.dentry;
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|  
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| --- a/fs/overlayfs/dir.c
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| +++ b/fs/overlayfs/dir.c
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| @@ -222,6 +222,9 @@ static struct dentry *ovl_clear_empty(st
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|  	struct kstat stat;
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|  	int err;
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|  
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| +	if (WARN_ON(!workdir))
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| +		return ERR_PTR(-EROFS);
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| +
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|  	err = ovl_lock_rename_workdir(workdir, upperdir);
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|  	if (err)
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|  		goto out;
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| @@ -322,6 +325,9 @@ static int ovl_create_over_whiteout(stru
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|  	struct dentry *newdentry;
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|  	int err;
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|  
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| +	if (WARN_ON(!workdir))
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| +		return -EROFS;
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| +
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|  	err = ovl_lock_rename_workdir(workdir, upperdir);
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|  	if (err)
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|  		goto out;
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| @@ -506,6 +512,9 @@ static int ovl_remove_and_whiteout(struc
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|  	struct dentry *opaquedir = NULL;
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|  	int err;
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|  
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| +	if (WARN_ON(!workdir))
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| +		return -EROFS;
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| +
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|  	if (is_dir) {
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|  		opaquedir = ovl_check_empty_and_clear(dentry);
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|  		err = PTR_ERR(opaquedir);
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| --- a/fs/overlayfs/super.c
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| +++ b/fs/overlayfs/super.c
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| @@ -740,9 +740,15 @@ static int ovl_fill_super(struct super_b
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|  	ufs->workdir = ovl_workdir_create(ufs->upper_mnt, workpath.dentry);
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|  	err = PTR_ERR(ufs->workdir);
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|  	if (IS_ERR(ufs->workdir)) {
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| -		pr_err("overlayfs: failed to create directory %s/%s\n",
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| -		       ufs->config.workdir, OVL_WORKDIR_NAME);
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| -		goto out_put_lower_mnt;
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| +		if (err == -ENOSPC || err == -EROFS) {
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| +			pr_warning("overlayfs: failed to create work directory (%s), mounting read-only\n", err == ENOSPC ? "ENOSPC" : "EROFS");
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| +			sb->s_flags |= MS_RDONLY;
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| +			ufs->workdir = NULL;
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| +		} else {
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| +			pr_err("overlayfs: failed to create directory %s/%s\n",
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| +			       ufs->config.workdir, OVL_WORKDIR_NAME);
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| +			goto out_put_lower_mnt;
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| +		}
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|  	}
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|  
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|  	/*
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