NFS: Fix inode corruption in nfs_prime_dcache() (7dc72d5f) · Commits · 戴 / test

Due to inode number reuse in filesystems, we can end up corrupting the inode on our client if we apply the file attributes without ensuring that the filehandle matches. Typical symptoms include spurious "mode changed" reports in the syslog. We still do want to ensure that we don't invalidate the dentry if the inode number matches, but we don't have a filehandle. Fixes: ("NFS: Don't require a filehandle to refresh...") Signed-off-by:

Trond Myklebust <trond.myklebust@primarydata.com> Cc: stable@vger.kernel.org # v4.0+ Tested-by:

Oleg Drokin <green@linuxhacker.ru> Signed-off-by:

Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/dir.c

+11 −5

Original line number	Diff line number	Diff line
		@@ -435,11 +435,11 @@ int nfs_same_file(struct dentry dentry, struct nfs_entry entry)
		return 0;

		nfsi = NFS_I(inode);
		if (entry->fattr->fileid == nfsi->fileid)
		return 1;
		if (nfs_compare_fh(entry->fh, &nfsi->fh) == 0)
		return 1;
		if (entry->fattr->fileid != nfsi->fileid)
		return 0;
		if (entry->fh->size && nfs_compare_fh(entry->fh, &nfsi->fh) != 0)
		return 0;
		return 1;
		}

		static
		@@ -525,6 +525,8 @@ again:
		&entry->fattr->fsid))
		goto out;
		if (nfs_same_file(dentry, entry)) {
		if (!entry->fh->size)
		goto out;
		nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
		status = nfs_refresh_inode(d_inode(dentry), entry->fattr);
		if (!status)
		@@ -537,6 +539,10 @@ again:
		goto again;
		}
		}
		if (!entry->fh->size) {
		d_lookup_done(dentry);
		goto out;
		}

		inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr, entry->label);
		alias = d_splice_alias(inode, dentry);

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