(2010/12/16 17:44), Tsutomu Itoh wrote:
> Hi,
>
> In btrfs, inode number is increased each time a new file or directory
> is made.
> Therefore, if the making deletion of the file is repeated, value of
> 'i_ino' increases rapidly.
>
> For example, inode number changes as follows.
>
> $ touch foo
> $ ls -i foo
> 266 foo
> $ rm foo
> $ touch bar
> $ ls -i bar
> 267 bar
> $
>
> And then, length of 'i_ino' and 'objectid' is as follows on the x86
> system.
>
> unsigned long i_ino == 32bits
> u64 objectid== 64bits
>
> Therefore, in the operation to substitute 'objectid' to 'i_ino',
> 'i_ino' overflows when 'objectid' 4294967296 is substituted to 'i_ino'.
> Then, the file with inode number 0 is made.
I think that it is better to recycle inode number that became unused.
And, at least, I think that it should make the filesystem not become an
abnormal condition.
This patch is a patch that makes an error when inode number is bigger
than BTRFS_LAST_FREE_OBJECTID.
Signed-off-by: Tsutomu Itoh
---
inode.c |4
1 file changed, 4 insertions(+)
diff -urNp linux-2.6.37-rc6/fs/btrfs/inode.c
linux-2.6.37-rc6.new/fs/btrfs/inode.c
--- linux-2.6.37-rc6/fs/btrfs/inode.c 2010-12-16 10:24:48.0 +0900
+++ linux-2.6.37-rc6.new/fs/btrfs/inode.c 2010-12-20 09:04:18.0
+0900
@@ -4529,6 +4529,10 @@ static struct inode *btrfs_new_inode(str
inode_init_owner(inode, dir, mode);
inode->i_ino = objectid;
+ if (unlikely(inode->i_ino > (unsigned long)BTRFS_LAST_FREE_OBJECTID)) {
+ ret = -ENOSPC;
+ goto fail;
+ }
inode_set_bytes(inode, 0);
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
> As a result, ls command has looped infinitely, and btrfsck detected the
> error.
> Please see below.
>
> $ uname -a
> Linux luna 2.6.37-rc5 #1 SMP Thu Dec 9 13:02:41 JST 2010 i686 i686 i386
> GNU/Linux
> $ df -T /test1
> FilesystemType 1K-blocks Used Available Use% Mounted on
> /dev/sdd14 btrfs 416256056 3717632 1% /test1
> $ strace -FfTttx ls /test1
> 14:03:10.115440 execve("/bin/ls", ["ls", "/test1"], [/* 28 vars */]) = 0
> <0.000181>
> ...
> ...
> 14:03:10.123431 stat("/test1", {st_mode=S_IFDIR|0777, st_size=8, ...}) = 0
> <0.17>
> 14:03:10.123521 open("/test1", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) =
> 3 <0.18>
> 14:03:10.123578 fcntl(3, F_GETFD) = 0x1 (flags FD_CLOEXEC) <0.13>
> 14:03:10.123637 getdents(3, /* 3 entries */, 32768) = 72 <0.25>
> 14:03:10.123712 getdents(3, /* 1 entries */, 32768) = 24 <0.16>
> 14:03:10.123768 getdents(3, /* 1 entries */, 32768) = 24 <0.15>
> 14:03:10.123824 getdents(3, /* 1 entries */, 32768) = 24 <0.15>
> 14:03:10.123880 getdents(3, /* 1 entries */, 32768) = 24 <0.15>
> 14:03:10.123936 getdents(3, /* 1 entries */, 32768) = 24 <0.14>
> 14:03:10.123992 getdents(3, /* 1 entries */, 32768) = 24 <0.15>
> 14:03:10.124047 getdents(3, /* 1 entries */, 32768) = 24 <0.15>
> 14:03:10.124103 getdents(3, /* 1 entries */, 32768) = 24 <0.15>
> 14:03:10.124261 getdents(3, /* 1 entries */, 32768) = 24 <0.16>
> 14:03:10.124320 getdents(3, /* 1 entries */, 32768) = 24 <0.15>
> 14:03:10.124381 getdents(3, /* 1 entries */, 32768) = 24 <0.15>
> 14:03:10.124437 getdents(3, /* 1 entries */, 32768) = 24 <0.14>
> 14:03:10.124493 getdents(3, /* 1 entries */, 32768) = 24 <0.14>
> 14:03:10.124549 getdents(3, /* 1 entries */, 32768) = 24 <0.14>
> 14:03:10.124605 getdents(3, /* 1 entries */, 32768) = 24 <0.14>
> 14:03:10.124661 getdents(3, /* 1 entries */, 32768) = 24 <0.14>
> 14:03:10.124717 getdents(3, /* 1 entries */, 32768) = 24 <0.14>
> 14:03:10.124773 getdents(3, /* 1 entries */, 32768) = 24 <0.14>
> 14:03:10.124840 getdents(3, /* 1 entries */, 32768) = 24 <0.14>
> 14:03:10.124896 getdents(3, /* 1 entries */, 32768) = 24 <0.14>
> ...
> ...
> $ cd /test1
> $ ls -i A123
> ls: cannot access A123: No such file or directory
> $ touch
> $ ls -i
> 1
> $
>
> # umount /test1
> # btrfsck /dev/sdd14
> root 5 inode 0 errors 2001
> unresolved ref dir 256 index 4294967041 namelen 4 name A123
> filetype 1 error 4
> root 5 inode 1 errors 2001
> unresolved ref dir 256 index 4294967042 namelen 4 name
> filetype 1 error 4
> root 5 inode 4294967296 errors 2000
> unresolved ref dir 256 index 4294967041 namelen 4 name A123
> filetype 0 error 3
> root 5 inode 4294967297 errors 2000
> unresolved ref dir 256 index 4294967042 namelen 4 name
> filetype 0 error 3
> found 28672 bytes used err is 1
> total csum bytes: 0
> total tree bytes: 28672
> total fs tree bytes: 8192
> btree space waste bytes: 23191
> file data blocks allocate