Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756142AbYJOOHG (ORCPT ); Wed, 15 Oct 2008 10:07:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754210AbYJOOEy (ORCPT ); Wed, 15 Oct 2008 10:04:54 -0400 Received: from mail.parknet.ad.jp ([210.171.162.6]:45121 "EHLO mail.officemail.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752173AbYJOOEs (ORCPT ); Wed, 15 Oct 2008 10:04:48 -0400 Subject: [PATCH 11/21] fat: Fix/Cleanup dcache handling for vfat To: akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, hirofumi@mail.parknet.co.jp From: OGAWA Hirofumi Date: Wed, 15 Oct 2008 22:57:59 +0900 Message-ID: <6caa18733e848f5f6e71122369.ps@mail.parknet.co.jp> References: <4e3b7e0f3e848f5f6e4222369.ps@mail.parknet.co.jp> <0f24bbb03e848f5f6e5322369.ps@mail.parknet.co.jp> <2dbbb6ea3e848f5f6e5422369.ps@mail.parknet.co.jp> <3adb30833e848f5f6e5522369.ps@mail.parknet.co.jp> <091baa8f3e848f5f6e6722369.ps@mail.parknet.co.jp> <649ecd633e848f5f6e6822369.ps@mail.parknet.co.jp> <2f7c69713e848f5f6e6922369.ps@mail.parknet.co.jp> In-Reply-To: X-Anti-Virus: Kaspersky Anti-Virus for MailServers 5.5.10/RELEASE, bases: 24052007 #308098, status: clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6549 Lines: 230 - Add comments for handling dcache of vfat. - Separate case-sensitive case and case-insensitive to vfat_revalidate() and vfat_ci_revalidate(). vfat_revalidate() doesn't need to drop case-insensitive negative dentry on creation path. - Current code is missing to set ->d_revalidate to the negative dentry created by unlink/etc.. This sets ->d_revalidate always, and returns 1 for positive dentry. Now, we don't need to change ->d_op dynamically anymore, so this just uses sb->s_root->d_op to set ->d_op. - d_find_alias() may return DCACHE_DISCONNECTED dentry. It's not the interesting dentry there. This checks it. - Add missing LOOKUP_PARENT check. We don't need to drop the valid negative dentry for (LOOKUP_CREATE | LOOKUP_PARENT) lookup. - For consistent filename on creation path, this drops negative dentry if we can't see intent. Signed-off-by: OGAWA Hirofumi --- fs/fat/namei_vfat.c | 124 ++++++++++++++++++++++++++++++++------------------- 1 file changed, 80 insertions(+), 44 deletions(-) diff -puN fs/fat/namei_vfat.c~vfat-dcache-fixes fs/fat/namei_vfat.c --- linux-2.6/fs/fat/namei_vfat.c~vfat-dcache-fixes 2008-08-27 14:57:52.000000000 +0900 +++ linux-2.6-hirofumi/fs/fat/namei_vfat.c 2008-08-27 18:41:22.000000000 +0900 @@ -24,27 +24,67 @@ #include #include "fat.h" -static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd) +/* + * If new entry was created in the parent, it could create the 8.3 + * alias (the shortname of logname). So, the parent may have the + * negative-dentry which matches the created 8.3 alias. + * + * If it happened, the negative dentry isn't actually negative + * anymore. So, drop it. + */ +static int vfat_revalidate_shortname(struct dentry *dentry) { int ret = 1; - - if (!dentry->d_inode && - nd && !(nd->flags & LOOKUP_CONTINUE) && (nd->flags & LOOKUP_CREATE)) - /* - * negative dentry is dropped, in order to make sure - * to use the name which a user desires if this is - * create path. - */ + spin_lock(&dentry->d_lock); + if (dentry->d_time != dentry->d_parent->d_inode->i_version) ret = 0; - else { - spin_lock(&dentry->d_lock); - if (dentry->d_time != dentry->d_parent->d_inode->i_version) - ret = 0; - spin_unlock(&dentry->d_lock); - } + spin_unlock(&dentry->d_lock); return ret; } +static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd) +{ + /* This is not negative dentry. Always valid. */ + if (dentry->d_inode) + return 1; + return vfat_revalidate_shortname(dentry); +} + +static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd) +{ + /* + * This is not negative dentry. Always valid. + * + * Note, rename() to existing directory entry will have ->d_inode, + * and will use existing name which isn't specified name by user. + * + * We may be able to drop this positive dentry here. But dropping + * positive dentry isn't good idea. So it's unsupported like + * rename("filename", "FILENAME") for now. + */ + if (dentry->d_inode) + return 1; + + /* + * This may be nfsd (or something), anyway, we can't see the + * intent of this. So, since this can be for creation, drop it. + */ + if (!nd) + return 0; + + /* + * Drop the negative dentry, in order to make sure to use the + * case sensitive name which is specified by user if this is + * for creation. + */ + if (!(nd->flags & (LOOKUP_CONTINUE | LOOKUP_PARENT))) { + if (nd->flags & LOOKUP_CREATE) + return 0; + } + + return vfat_revalidate_shortname(dentry); +} + /* returns the length of a struct qstr, ignoring trailing dots */ static unsigned int vfat_striptail_len(struct qstr *qstr) { @@ -126,25 +166,16 @@ static int vfat_cmp(struct dentry *dentr return 1; } -static struct dentry_operations vfat_dentry_ops[4] = { - { - .d_hash = vfat_hashi, - .d_compare = vfat_cmpi, - }, - { - .d_revalidate = vfat_revalidate, - .d_hash = vfat_hashi, - .d_compare = vfat_cmpi, - }, - { - .d_hash = vfat_hash, - .d_compare = vfat_cmp, - }, - { - .d_revalidate = vfat_revalidate, - .d_hash = vfat_hash, - .d_compare = vfat_cmp, - } +static struct dentry_operations vfat_ci_dentry_ops = { + .d_revalidate = vfat_revalidate_ci, + .d_hash = vfat_hashi, + .d_compare = vfat_cmpi, +}; + +static struct dentry_operations vfat_dentry_ops = { + .d_revalidate = vfat_revalidate, + .d_hash = vfat_hash, + .d_compare = vfat_cmp, }; /* Characters that are undesirable in an MS-DOS file name */ @@ -685,29 +716,35 @@ static struct dentry *vfat_lookup(struct struct fat_slot_info sinfo; struct inode *inode; struct dentry *alias; - int err, table; + int err; lock_super(sb); - table = (MSDOS_SB(sb)->options.name_check == 's') ? 2 : 0; - dentry->d_op = &vfat_dentry_ops[table]; err = vfat_find(dir, &dentry->d_name, &sinfo); if (err) { if (err == -ENOENT) { - table++; inode = NULL; goto out; } goto error; } + inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); brelse(sinfo.bh); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto error; } + alias = d_find_alias(inode); - if (alias) { + if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) { + /* + * This inode has non DCACHE_DISCONNECTED dentry. This + * means, the user did ->lookup() by an another name + * (longname vs 8.3 alias of it) in past. + * + * Switch to new one for reason of locality if possible. + */ if (d_invalidate(alias) == 0) dput(alias); else { @@ -715,15 +752,14 @@ static struct dentry *vfat_lookup(struct unlock_super(sb); return alias; } - } out: unlock_super(sb); - dentry->d_op = &vfat_dentry_ops[table]; + dentry->d_op = sb->s_root->d_op; dentry->d_time = dentry->d_parent->d_inode->i_version; dentry = d_splice_alias(inode, dentry); if (dentry) { - dentry->d_op = &vfat_dentry_ops[table]; + dentry->d_op = sb->s_root->d_op; dentry->d_time = dentry->d_parent->d_inode->i_version; } return dentry; @@ -1022,9 +1058,9 @@ static int vfat_fill_super(struct super_ return res; if (MSDOS_SB(sb)->options.name_check != 's') - sb->s_root->d_op = &vfat_dentry_ops[0]; + sb->s_root->d_op = &vfat_ci_dentry_ops; else - sb->s_root->d_op = &vfat_dentry_ops[2]; + sb->s_root->d_op = &vfat_dentry_ops; return 0; } _ -- 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/