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Revision 8ca15e05e6ac2745725d2d62394cfbe4ac335e84 authored by Josef Bacik on 05 July 2013, 17:58:19 UTC, committed by Chris Mason on 09 August 2013, 23:29:56 UTC 
Btrfs: fix backref walking when we hit a compressed extent
 
If you do btrfs inspect-internal logical-resolve on a compressed extent that has
been partly overwritten it won't find anything.  This is because we try and
match the extent offset we've searched for based on the extent offset in the
data extent entry.  However this doesn't work for compressed extents because the
offsets are for the uncompressed size, not the compressed size.  So instead only
do this check if we are not compressed, that way we can get an actual entry for
the physical offset rather than nothing for compressed.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
1 parent b76bb70
Raw File
svcshare.c 
/*
 * linux/fs/lockd/svcshare.c
 *
 * Management of DOS shares.
 *
 * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/time.h>
#include <linux/unistd.h>
#include <linux/string.h>
#include <linux/slab.h>

#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/lockd/lockd.h>
#include <linux/lockd/share.h>

static inline int
nlm_cmp_owner(struct nlm_share *share, struct xdr_netobj *oh)
{
	return share->s_owner.len == oh->len
	    && !memcmp(share->s_owner.data, oh->data, oh->len);
}

__be32
nlmsvc_share_file(struct nlm_host *host, struct nlm_file *file,
			struct nlm_args *argp)
{
	struct nlm_share	*share;
	struct xdr_netobj	*oh = &argp->lock.oh;
	u8			*ohdata;

	for (share = file->f_shares; share; share = share->s_next) {
		if (share->s_host == host && nlm_cmp_owner(share, oh))
			goto update;
		if ((argp->fsm_access & share->s_mode)
		 || (argp->fsm_mode   & share->s_access ))
			return nlm_lck_denied;
	}

	share = kmalloc(sizeof(*share) + oh->len,
						GFP_KERNEL);
	if (share == NULL)
		return nlm_lck_denied_nolocks;

	/* Copy owner handle */
	ohdata = (u8 *) (share + 1);
	memcpy(ohdata, oh->data, oh->len);

	share->s_file	    = file;
	share->s_host       = host;
	share->s_owner.data = ohdata;
	share->s_owner.len  = oh->len;
	share->s_next       = file->f_shares;
	file->f_shares      = share;

update:
	share->s_access = argp->fsm_access;
	share->s_mode   = argp->fsm_mode;
	return nlm_granted;
}

/*
 * Delete a share.
 */
__be32
nlmsvc_unshare_file(struct nlm_host *host, struct nlm_file *file,
			struct nlm_args *argp)
{
	struct nlm_share	*share, **shpp;
	struct xdr_netobj	*oh = &argp->lock.oh;

	for (shpp = &file->f_shares; (share = *shpp) != NULL;
					shpp = &share->s_next) {
		if (share->s_host == host && nlm_cmp_owner(share, oh)) {
			*shpp = share->s_next;
			kfree(share);
			return nlm_granted;
		}
	}

	/* X/Open spec says return success even if there was no
	 * corresponding share. */
	return nlm_granted;
}

/*
 * Traverse all shares for a given file, and delete
 * those owned by the given (type of) host
 */
void nlmsvc_traverse_shares(struct nlm_host *host, struct nlm_file *file,
		nlm_host_match_fn_t match)
{
	struct nlm_share	*share, **shpp;

	shpp = &file->f_shares;
	while ((share = *shpp) !=  NULL) {
		if (match(share->s_host, host)) {
			*shpp = share->s_next;
			kfree(share);
			continue;
		}
		shpp = &share->s_next;
	}
}
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