From ecfd890991a26e70547e025673580923a004c5e4 Mon Sep 17 00:00:00 2001 From: Prasad Joshi Date: Sun, 30 Oct 2011 22:15:32 +0530 Subject: [PATCH] logfs: set superblock shutdown flag after generic sb shutdown While unmounting the file system LogFS calls generic_shutdown_super. The function does file system independent superblock shutdown. However, it might result in call file system specific inode eviction. LogFS marks FS shutting down by setting bit LOGFS_SB_FLAG_SHUTDOWN in super->s_flags. Since, inode eviction might call truncate on inode, following BUG is observed when file system is unmounted: ------------[ cut here ]------------ kernel BUG at /home/prasad/logfs/segment.c:362! invalid opcode: 0000 [#1] PREEMPT SMP CPU 3 Modules linked in: logfs binfmt_misc ppdev virtio_blk parport_pc lp parport psmouse floppy virtio_pci serio_raw virtio_ring virtio Pid: 1933, comm: umount Not tainted 3.0.0+ #4 Bochs Bochs RIP: 0010:[] [] logfs_segment_write+0x211/0x230 [logfs] RSP: 0018:ffff880062d7b9e8 EFLAGS: 00010202 RAX: 000000000000000e RBX: ffff88006eca9000 RCX: 0000000000000000 RDX: ffff88006fd87c40 RSI: ffffea00014ff468 RDI: ffff88007b68e000 RBP: ffff880062d7ba48 R08: 8000000020451430 R09: 0000000000000000 R10: dead000000100100 R11: 0000000000000000 R12: ffff88006fd87c40 R13: ffffea00014ff468 R14: ffff88005ad0a460 R15: 0000000000000000 FS: 00007f25d50ea760(0000) GS:ffff88007fd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000d05e48 CR3: 0000000062c72000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process umount (pid: 1933, threadinfo ffff880062d7a000, task ffff880070b44500) Stack: ffff880062d7ba38 ffff88005ad0a508 0000000000001000 0000000000000000 8000000020451430 ffffea00014ff468 ffff880062d7ba48 ffff88005ad0a460 ffff880062d7bad8 ffffea00014ff468 ffff88006fd87c40 0000000000000000 Call Trace: [] logfs_write_i0+0x12e/0x190 [logfs] [] __logfs_write_rec+0x140/0x220 [logfs] [] __logfs_write_rec+0xf2/0x220 [logfs] [] logfs_write_rec+0x64/0xd0 [logfs] [] __logfs_write_buf+0x106/0x110 [logfs] [] logfs_write_buf+0x4e/0x80 [logfs] [] __logfs_write_inode+0x98/0x110 [logfs] [] logfs_truncate+0x54/0x290 [logfs] [] logfs_evict_inode+0xdc/0x190 [logfs] [] evict+0x85/0x170 [] iput+0xe6/0x1b0 [] shrink_dcache_for_umount_subtree+0x218/0x280 [] shrink_dcache_for_umount+0x51/0x90 [] generic_shutdown_super+0x2c/0x100 [] logfs_kill_sb+0x57/0xf0 [logfs] [] deactivate_locked_super+0x45/0x70 [] deactivate_super+0x4a/0x70 [] mntput_no_expire+0xa4/0xf0 [] sys_umount+0x6f/0x380 [] system_call_fastpath+0x16/0x1b Code: 55 c8 49 8d b6 a8 00 00 00 45 89 f9 45 89 e8 4c 89 e1 4c 89 55 b8 c7 04 24 00 00 00 00 e8 68 fc ff ff 4c 8b 55 b8 e9 3c ff ff ff <0f> 0b 0f 0b c7 45 c0 00 00 00 00 e9 44 fe ff ff 66 66 66 66 66 RIP [] logfs_segment_write+0x211/0x230 [logfs] RSP ---[ end trace fe6b040cea952290 ]--- Therefore, move super->s_flags setting after the fs-indenpendent work has been finished. Reviewed-by: Joern Engel Signed-off-by: Prasad Joshi --- fs/logfs/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/logfs/super.c b/fs/logfs/super.c index e795c234ea3..f9b7a30b00a 100644 --- a/fs/logfs/super.c +++ b/fs/logfs/super.c @@ -491,9 +491,9 @@ static void logfs_kill_sb(struct super_block *sb) * From this point on alias entries are simply dropped - and any * writes to the object store are considered bugs. */ - super->s_flags |= LOGFS_SB_FLAG_SHUTDOWN; log_super("LogFS: Now in shutdown\n"); generic_shutdown_super(sb); + super->s_flags |= LOGFS_SB_FLAG_SHUTDOWN; BUG_ON(super->s_dirty_used_bytes || super->s_dirty_free_bytes); -- 2.11.4.GIT