On Sat, 5 Jul 2014, Theodore Ts'o wrote: > Date: Sat, 5 Jul 2014 16:28:51 -0400 > From: Theodore Ts'o <[email protected]> > To: Ext4 Developers List <[email protected]> > Cc: Theodore Ts'o <[email protected]>, [email protected] > Subject: [PATCH] ext4: fix unjournalled bg descriptor while initializing inode > bitmap > > The first time that we allocate from an uninitialized inode allocation > bitmap, if the block allocation bitmap is also uninitalized, we need > to get write access to the block group descriptor before we start > modifying the block group descriptor flags and updating the free block > count, etc. Otherwise, there is the potential of a bad journal > checksum (if journal checksums are enabled), and of the file system > becoming inconsistent if we crash at exactly the wrong time.
Looks good. Reviewed-by: Lukas Czerner <[email protected]> > > Signed-off-by: Theodore Ts'o <[email protected]> > Cc: [email protected] > --- > fs/ext4/ialloc.c | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c > index a87455d..0840bf3 100644 > --- a/fs/ext4/ialloc.c > +++ b/fs/ext4/ialloc.c > @@ -874,6 +874,13 @@ got: > goto out; > } > > + BUFFER_TRACE(group_desc_bh, "get_write_access"); > + err = ext4_journal_get_write_access(handle, group_desc_bh); > + if (err) { > + ext4_std_error(sb, err); > + goto out; > + } > + > /* We may have to initialize the block bitmap if it isn't already */ > if (ext4_has_group_desc_csum(sb) && > gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { > @@ -910,13 +917,6 @@ got: > } > } > > - BUFFER_TRACE(group_desc_bh, "get_write_access"); > - err = ext4_journal_get_write_access(handle, group_desc_bh); > - if (err) { > - ext4_std_error(sb, err); > - goto out; > - } > - > /* Update the relevant bg descriptor fields */ > if (ext4_has_group_desc_csum(sb)) { > int free; > -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
