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 <lopresti@gmail.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
This commit is contained in:
Patrick J. LoPresti 2010-07-22 15:05:57 -07:00 коммит произвёл Joel Becker
Родитель 1113e1b504
Коммит 3bdb8efd94
1 изменённых файлов: 46 добавлений и 5 удалений

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@ -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 :) */