On Thu, May 14, 2009 at 4:37 PM, Kevin Shanahan <kmshanah@xxxxxxxxxxx> wrote: > On Thu, May 14, 2009 at 12:40:11AM -0400, Theodore Tso wrote: >> On Wed, May 13, 2009 at 03:56:34PM +0930, Kevin Shanahan wrote: >> > >> > Now, this is (possibly) interesting - that block contains a bunch of >> > file data. Looks like a html email (I can tell it's email because of >> > the FIXED_ prefix added to the tags by the mail sanitizer). >> >> That is interesting. Knowing that it is file data means we might be >> able to track things down this way. >> >> Are you able to apply the following patch to your kernel? Hi Ted, If we have the possibility of applying patches why not apply this too and try http://markmail.org/message/e3uwzxrd42isxczg . After all it originated from this bug only. Thanks - Manish >> If so, >> hopefully we'll be able to catch whatever is causing the problem in >> the act. > > Sure - now running with 2.6.29.3 + your patch. > > patching file fs/ext4/inode.c > Hunk #1 succeeded at 1040 with fuzz 1 (offset -80 lines). > Hunk #2 succeeded at 1113 (offset -81 lines). > Hunk #3 succeeded at 1184 (offset -93 lines). > > I'll report any hits for "check_block_validity" in syslog. > > Thankyou, much appreciated. > > Cheers, > Kevin. > >> commit 8ff799da106e9fc4da9b2a3753b5b86caab27f13 >> Author: Theodore Ts'o <tytso@xxxxxxx> >> Date: Thu May 14 00:39:48 2009 -0400 >> >> ext4: Add a block validity check to ext4_get_blocks_wrap() >> >> A few users with very large disks have been reporting low block number >> filesystem corruptions, potentially zapping the block group >> descriptors or inodes in the first inode table block. It's not clear >> what is causing this, but most recently, it appears that whatever is >> trashing the filesystem metadata appears to be file data. So let's >> try to set a trap for the corruption in ext4_get_blocks_wrap(), which >> is where logical blocks in an inode are mapped to physical blocks. >> >> Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx> >> >> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c >> index 4e7f363..4fad4fa 100644 >> --- a/fs/ext4/inode.c >> +++ b/fs/ext4/inode.c >> @@ -1120,6 +1120,35 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used) >> ext4_discard_preallocations(inode); >> } >> >> +static int check_block_validity(struct inode *inode, sector_t logical, >> + sector_t phys, int len) >> +{ >> + ext4_fsblk_t valid_block, itable_block; >> + struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es; >> + struct ext4_group_desc *gdp = ext4_get_group_desc(inode->i_sb, 0, 0); >> + unsigned int itable_len = EXT4_SB(inode->i_sb)->s_itb_per_group; >> + >> + valid_block = le32_to_cpu(es->s_first_data_block) + >> + EXT4_SB(inode->i_sb)->s_gdb_count; >> + itable_block = ext4_inode_table(inode->i_sb, gdp); >> + >> + if (unlikely((phys <= valid_block) || >> + ((phys + len - 1) > ext4_blocks_count(es)) || >> + ((phys >= itable_block) && >> + (phys <= itable_block + itable_len)) || >> + ((phys + len - 1 >= itable_block) && >> + (phys + len - 1 <= itable_block + itable_len)))) { >> + ext4_error(inode->i_sb, "check_block_validity", >> + "inode #%lu logical block %llu mapped to %llu " >> + "(size %d)", inode->i_ino, >> + (unsigned long long) logical, >> + (unsigned long long) phys, len); >> + WARN_ON(1); >> + return -EIO; >> + } >> + return 0; >> +} >> + >> /* >> * The ext4_get_blocks_wrap() function try to look up the requested blocks, >> * and returns if the blocks are already mapped. >> @@ -1165,6 +1194,13 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block, >> } >> up_read((&EXT4_I(inode)->i_data_sem)); >> >> + if (retval > 0 && buffer_mapped(bh)) { >> + int ret = check_block_validity(inode, block, >> + bh->b_blocknr, retval); >> + if (ret != 0) >> + return ret; >> + } >> + >> /* If it is only a block(s) look up */ >> if (!create) >> return retval; >> @@ -1241,6 +1277,12 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block, >> } >> >> up_write((&EXT4_I(inode)->i_data_sem)); >> + if (retval > 0 && buffer_mapped(bh)) { >> + int ret = check_block_validity(inode, block, >> + bh->b_blocknr, retval); >> + if (ret != 0) >> + return ret; >> + } >> return retval; >> } >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Thanks - Manish -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
