From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Sandeen Subject: [PATCH] ext4: feature set check helper for mount & remount paths Date: Sun, 16 Aug 2009 15:22:36 -0500 Message-ID: <4A886A8C.9090909@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: ext4 development Return-path: Received: from mx2.redhat.com ([66.187.237.31]:52733 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755884AbZHPUWg (ORCPT ); Sun, 16 Aug 2009 16:22:36 -0400 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n7GKMbqb027891 for ; Sun, 16 Aug 2009 16:22:37 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx2.corp.redhat.com (8.13.1/8.13.1) with ESMTP id n7GKMbCj009323 for ; Sun, 16 Aug 2009 16:22:37 -0400 Received: from Liberator.lan (sebastian-int.corp.redhat.com [172.16.52.221]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id n7GKMaEC013352 for ; Sun, 16 Aug 2009 16:22:36 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: A user reported that although his root ext4 filesystem was mounting fine, other filesystems would not mount, with the: "Filesystem with huge files cannot be mounted RDWR without CONFIG_LBDAF" error on his 32-bit box built without CONFIG_LBDAF. This is because the test at mount time for this situation was not being re-checked on remount, and the normal boot process makes an ro->rw transition, so this was being missed. Refactor to make a common helper function to test the filesystem features against the type of mount request (RO vs. RW) so that we stay consistent. Addresses Red Hat bugzilla 517650. Compile-tested only. Signed-off-by: Eric Sandeen --- super.c | 91 ++++++++++++++++++++++++++++++++++------------------------------ 1 file changed, 49 insertions(+), 42 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 59b80b1..4f4714e 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2253,6 +2253,49 @@ static struct kobj_type ext4_ktype = { .release = ext4_sb_release, }; +/* + * Check whether this filesystem can be mounted based on + * the features present and the RDONLY/RDWR mount requested. + * Returns 1 if this filesystem can be mounted as requested, + * 0 if it cannot be. + */ +static int ext4_feature_set_ok(struct super_block *sb, int readonly) +{ + if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) { + ext4_msg(sb, KERN_ERR, + "Couldn't mount because of " + "unsupported optional features (%x)", + (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) & + ~EXT4_FEATURE_INCOMPAT_SUPP)); + return 0; + } + + if (readonly) + return 1; + + /* Check that feature set is OK for a read-write mount */ + if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) { + ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of " + "unsupported optional features (%x)", + (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) & + ~EXT4_FEATURE_RO_COMPAT_SUPP)); + return 0; + } + /* + * Large file size enabled file system can only be mounted + * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF + */ + if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) { + if (sizeof(blkcnt_t) < sizeof(u64)) { + ext4_msg(sb, KERN_ERR, "Filesystem with huge files " + "cannot be mounted RDWR without " + "CONFIG_LBDAF"); + return 0; + } + } + return 1; +} + static int ext4_fill_super(struct super_block *sb, void *data, int silent) __releases(kernel_lock) __acquires(kernel_lock) @@ -2274,7 +2317,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) unsigned int db_count; unsigned int i; int needs_recovery, has_huge_files; - int features; __u64 blocks_count; int err; unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO; @@ -2401,39 +2443,9 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) * previously didn't change the revision level when setting the flags, * so there is a chance incompat flags are set on a rev 0 filesystem. */ - features = EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP); - if (features) { - ext4_msg(sb, KERN_ERR, - "Couldn't mount because of " - "unsupported optional features (%x)", - (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) & - ~EXT4_FEATURE_INCOMPAT_SUPP)); - goto failed_mount; - } - features = EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP); - if (!(sb->s_flags & MS_RDONLY) && features) { - ext4_msg(sb, KERN_ERR, - "Couldn't mount RDWR because of " - "unsupported optional features (%x)", - (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) & - ~EXT4_FEATURE_RO_COMPAT_SUPP)); + if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY))) goto failed_mount; - } - has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb, - EXT4_FEATURE_RO_COMPAT_HUGE_FILE); - if (has_huge_files) { - /* - * Large file size enabled file system can only be - * mount if kernel is build with CONFIG_LBDAF - */ - if (sizeof(root->i_blocks) < sizeof(u64) && - !(sb->s_flags & MS_RDONLY)) { - ext4_msg(sb, KERN_ERR, "Filesystem with huge " - "files cannot be mounted read-write " - "without CONFIG_LBDAF"); - goto failed_mount; - } - } + blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size); if (blocksize < EXT4_MIN_BLOCK_SIZE || @@ -2469,6 +2481,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) } } + has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb, + EXT4_FEATURE_RO_COMPAT_HUGE_FILE); sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits, has_huge_files); sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files); @@ -3474,18 +3488,11 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) if (sbi->s_journal) ext4_mark_recovery_complete(sb, es); } else { - int ret; - if ((ret = EXT4_HAS_RO_COMPAT_FEATURE(sb, - ~EXT4_FEATURE_RO_COMPAT_SUPP))) { - ext4_msg(sb, KERN_WARNING, "couldn't " - "remount RDWR because of unsupported " - "optional features (%x)", - (le32_to_cpu(sbi->s_es->s_feature_ro_compat) & - ~EXT4_FEATURE_RO_COMPAT_SUPP)); + /* Make sure we can mount this feature set readwrite */ + if (!ext4_feature_set_ok(sb, 0)) { err = -EROFS; goto restore_opts; }