From 3bdb8efd94a73bb137e3315cd831cbc874052b4b Mon Sep 17 00:00:00 2001 From: "Patrick J. LoPresti" Date: Thu, 22 Jul 2010 15:05:57 -0700 Subject: [PATCH] OCFS2: Allow huge (> 16 TiB) volumes to mount The OCFS2 developers have already done all of the hard work to allow volumes larger than 16 TiB. But there is still a "sanity check" in fs/ocfs2/super.c that prevents the mounting of such volumes, even when the cluster size and journal options would allow it. This patch replaces that sanity check with a more sophisticated one to mount a huge volume provided that (a) it is addressable by the raw word/address size of the system (borrowing a test from ext4); (b) the volume is using JBD2; and (c) the JBD2_FEATURE_INCOMPAT_64BIT flag is set on the journal. I factored out the sanity check into its own function. I also moved it from ocfs2_initialize_super() down to ocfs2_check_volume(); any earlier, and the journal will not have been initialized yet. This patch is one of a pair, and it depends on the other ("JBD2: Allow feature checks before journal recovery"). I have tested this patch on small volumes, huge volumes, and huge volumes without 64-bit block support in the journal. All of them appear to work or to fail gracefully, as appropriate. Signed-off-by: Patrick LoPresti Signed-off-by: Joel Becker --- fs/ocfs2/super.c | 51 +++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 46 insertions(+), 5 deletions(-) diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index fa1be1b304d..47415398d56 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -1990,6 +1990,36 @@ static int ocfs2_setup_osb_uuid(struct ocfs2_super *osb, const unsigned char *uu return 0; } +/* Make sure entire volume is addressable by our journal. Requires + osb_clusters_at_boot to be valid and for the journal to have been + initialized by ocfs2_journal_init(). */ +static int ocfs2_journal_addressable(struct ocfs2_super *osb) +{ + int status = 0; + u64 max_block = + ocfs2_clusters_to_blocks(osb->sb, + osb->osb_clusters_at_boot) - 1; + + /* 32-bit block number is always OK. */ + if (max_block <= (u32)~0ULL) + goto out; + + /* Volume is "huge", so see if our journal is new enough to + support it. */ + if (!(OCFS2_HAS_COMPAT_FEATURE(osb->sb, + OCFS2_FEATURE_COMPAT_JBD2_SB) && + jbd2_journal_check_used_features(osb->journal->j_journal, 0, 0, + JBD2_FEATURE_INCOMPAT_64BIT))) { + mlog(ML_ERROR, "The journal cannot address the entire volume. " + "Enable the 'block64' journal option with tunefs.ocfs2"); + status = -EFBIG; + goto out; + } + + out: + return status; +} + static int ocfs2_initialize_super(struct super_block *sb, struct buffer_head *bh, int sector_size, @@ -2002,6 +2032,7 @@ static int ocfs2_initialize_super(struct super_block *sb, struct ocfs2_journal *journal; __le32 uuid_net_key; struct ocfs2_super *osb; + u64 total_blocks; mlog_entry_void(); @@ -2214,11 +2245,15 @@ static int ocfs2_initialize_super(struct super_block *sb, goto bail; } - if (ocfs2_clusters_to_blocks(osb->sb, le32_to_cpu(di->i_clusters) - 1) - > (u32)~0UL) { - mlog(ML_ERROR, "Volume might try to write to blocks beyond " - "what jbd can address in 32 bits.\n"); - status = -EINVAL; + total_blocks = ocfs2_clusters_to_blocks(osb->sb, + le32_to_cpu(di->i_clusters)); + + status = generic_check_addressable(osb->sb->s_blocksize_bits, + total_blocks); + if (status) { + mlog(ML_ERROR, "Volume too large " + "to mount safely on this system"); + status = -EFBIG; goto bail; } @@ -2380,6 +2415,12 @@ static int ocfs2_check_volume(struct ocfs2_super *osb) goto finally; } + /* Now that journal has been initialized, check to make sure + entire volume is addressable. */ + status = ocfs2_journal_addressable(osb); + if (status) + goto finally; + /* If the journal was unmounted cleanly then we don't want to * recover anything. Otherwise, journal_load will do that * dirty work for us :) */ -- 2.20.1