Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932684AbWKGP42 (ORCPT ); Tue, 7 Nov 2006 10:56:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964786AbWKGP41 (ORCPT ); Tue, 7 Nov 2006 10:56:27 -0500 Received: from mx1.redhat.com ([66.187.233.31]:28575 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S932635AbWKGP4P (ORCPT ); Tue, 7 Nov 2006 10:56:15 -0500 Subject: Re: [PATCH] make last_inode counter in new_inode 32-bit on kernels that offer x86 compatability From: Jeff Layton To: Eric Sandeen Cc: =?ISO-8859-1?Q?J=F6rn?= Engel , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <454FAAF8.8080707@redhat.com> References: <1162836725.6952.28.camel@dantu.rdu.redhat.com> <20061106182222.GO27140@parisc-linux.org> <1162838843.12129.8.camel@dantu.rdu.redhat.com> <20061106202313.GA691@wohnheim.fh-wedel.de> <454FA032.1070008@redhat.com> <20061106211134.GB691@wohnheim.fh-wedel.de> <454FAAF8.8080707@redhat.com> Content-Type: text/plain Date: Tue, 07 Nov 2006 10:56:06 -0500 Message-Id: <1162914966.28425.24.camel@dantu.rdu.redhat.com> Mime-Version: 1.0 X-Mailer: Evolution 2.8.0 (2.8.0-7.fc6) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3805 Lines: 129 On Mon, 2006-11-06 at 15:36 -0600, Eric Sandeen wrote: > *shrug* I dunno, it's probably not worth arguing this point, it needs to > be fixed properly in any case. :) > > -Eric Here's a more involved (again, untested) patch. I turned new_inode into a wrapper for a new function (new_inode_autonum). If the autonum arg is set, then we should get back a unique i_ino. This also converts the iunique function to use the per sb s_lastino counter. I think that's the right thing to do here, but I'm new to the hlist stuff and so feedback would be appreciated there. Current behavior for new_inode shouldn't be changed (aside from the per-sb s_lastino counter). The idea here would be to move filesystems that don't later overwrite the i_ino field, to use new_inode_autonum rather than new_inode and set autonum to true. Not sure how bad performance with new inode creation will be when that is set to true, but this is the best way I could see to do this without adding something like an radix tree to track used inodes. Signed-off-by: Jeff Layton diff --git a/fs/inode.c b/fs/inode.c index 26cdb11..83b9bab 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -517,14 +517,14 @@ repeat: } /** - * new_inode - obtain an inode + * new_inode_autonum - obtain an inode * @sb: superblock + * @autonum: if true, make sure that i_ino is unique * * Allocates a new inode for given superblock. */ -struct inode *new_inode(struct super_block *sb) +struct inode *new_inode_autonum(struct super_block *sb, int autonum) { - static unsigned long last_ino; struct inode * inode; spin_lock_prefetch(&inode_lock); @@ -535,13 +535,26 @@ struct inode *new_inode(struct super_blo inodes_stat.nr_inodes++; list_add(&inode->i_list, &inode_in_use); list_add(&inode->i_sb_list, &sb->s_inodes); - inode->i_ino = ++last_ino; + if (autonum) + inode->i_ino = iunique(sb, 0); + else + inode->i_ino = ++sb->s_lastino; inode->i_state = 0; spin_unlock(&inode_lock); } return inode; } +/** + * new_inode - obtain an inode + * @sb: superblock + * + * Allocates a new inode for given superblock. + */ +struct inode *new_inode(struct super_block *sb) +{ + new_inode_autonum(sb, 0); +} EXPORT_SYMBOL(new_inode); void unlock_new_inode(struct inode *inode) @@ -683,22 +696,21 @@ static unsigned long hash(struct super_b */ ino_t iunique(struct super_block *sb, ino_t max_reserved) { - static ino_t counter; struct inode *inode; struct hlist_head * head; ino_t res; spin_lock(&inode_lock); retry: - if (counter > max_reserved) { - head = inode_hashtable + hash(sb,counter); - res = counter++; + if (sb->s_lastino >= max_reserved) { + head = inode_hashtable + hash(sb,++sb->s_lastino); + res = sb->s_lastino; inode = find_inode_fast(sb, head, res); if (!inode) { spin_unlock(&inode_lock); return res; } } else { - counter = max_reserved + 1; + sb->s_lastino = max_reserved; } goto retry; diff --git a/fs/super.c b/fs/super.c diff --git a/include/linux/fs.h b/include/linux/fs.h index 2fe6e3f..1010e64 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -961,6 +961,14 @@ #endif /* Granularity of c/m/atime in ns. Cannot be worse than a second */ u32 s_time_gran; + + /* per-sb inode counter for new_inode. Make it a 32-bit counter when + we have the possibility of dealing with 32-bit apps */ +#ifdef CONFIG_COMPAT + unsigned int s_lastino; +#else + unsigned long s_lastino; +#endif }; extern struct timespec current_fs_time(struct super_block *sb); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/