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Description of problem: I'm doing rmmod->insmod->mount->umount loop stress testing, and btrfs failed to be inserted after hundreds of loops. slab error in kmem_cache_destroy(): cache `extent_buffers': Can't free all objects Pid: 40487, comm: modprobe Tainted: G ---------------- T 2.6.32-189.el6.x86_64 #1 Call Trace: [<ffffffff8116111b>] ? kmem_cache_destroy+0xbb/0xf0 [<ffffffffa07ae25c>] ? extent_io_exit+0x5c/0x100 [btrfs] [<ffffffffa07d70fc>] ? exit_btrfs_fs+0x18/0x6be [btrfs] [<ffffffff810ac3d4>] ? sys_delete_module+0x194/0x260 [<ffffffff810d43d2>] ? audit_syscall_entry+0x272/0x2a0 [<ffffffff814f00de>] ? do_page_fault+0x3e/0xa0 [<ffffffff8100b0b2>] ? system_call_fastpath+0x16/0x1b TECH PREVIEW: btrfs may not be fully supported. Please review provided documentation for limitations. kmem_cache_create: duplicate cache extent_buffers Pid: 40488, comm: modprobe Tainted: G ---------------- T 2.6.32-189.el6.x86_64 #1 Call Trace: [<ffffffff81161688>] ? kmem_cache_create+0x538/0x5a0 [<ffffffffa0898000>] ? init_btrfs_fs+0x0/0xb1 [btrfs] [<ffffffffa089812d>] ? extent_io_init+0x4b/0x6e [btrfs] [<ffffffffa0898041>] ? init_btrfs_fs+0x41/0xb1 [btrfs] [<ffffffff8100204c>] ? do_one_initcall+0x3c/0x1d0 [<ffffffff810af371>] ? sys_init_module+0xe1/0x250 [<ffffffff8100b0b2>] ? system_call_fastpath+0x16/0x1b Version-Release number of selected component (if applicable): kernel-2.6.32-191.el6 How reproducible: Reliable, 5/5 for now Steps to Reproduce: 1. find a btrfs partition 2. while true; do modprobe -r btrfs;modprobe btrfs;mount /dev/sda5 /mnt/test;umount /dev/sda5;done 3. wait for a while Actual results: modprobe btrfs failed Expected results: test pass Additional info: A failed beaker job: https://beaker.engineering.redhat.com/jobs/122396
Since RHEL 6.2 External Beta has begun, and this bug remains unresolved, it has been rejected as it is not proposed as exception or blocker. Red Hat invites you to ask your support representative to propose this request, if appropriate and relevant, in the next release of Red Hat Enterprise Linux.
*** This bug has been marked as a duplicate of bug 698324 ***
I still could reproduce it on kernel-2.6.32-358.el6, reopen it. + modprobe btrfs FATAL: Error inserting btrfs (/lib/modules/2.6.32-358.el6.x86_64/kernel/fs/btrfs/btrfs.ko): Cannot allocate memory TECH PREVIEW: btrfs may not be fully supported. Please review provided documentation for limitations. kmem_cache_create: duplicate cache extent_buffers Pid: 7765, comm: modprobe Tainted: G --------------- T 2.6.32-358.el6.x86_64 #1 Call Trace: [<ffffffff8116aaf8>] ? kmem_cache_create+0x538/0x5a0 [<ffffffffa06ce000>] ? init_btrfs_fs+0x0/0xbb [btrfs] [<ffffffffa06ce137>] ? extent_io_init+0x4b/0x6e [btrfs] [<ffffffffa06ce03b>] ? init_btrfs_fs+0x3b/0xbb [btrfs] [<ffffffff8100204c>] ? do_one_initcall+0x3c/0x1d0 [<ffffffff810b7551>] ? sys_init_module+0xe1/0x250 [<ffffffff8100b072>] ? system_call_fastpath+0x16/0x1b '9b4be454-8e67-400b-9eb7-347b403b87c1'
Just note, still fails on kernel-2.6.32-488.el6 slab error in kmem_cache_destroy(): cache `extent_buffers': Can't free all objects Pid: 22762, comm: modprobe Tainted: G --------------- T 2.6.32-488.el6.x86_64 #1 Call Trace: [<ffffffff811763fb>] ? kmem_cache_destroy+0xbb/0xf0 [<ffffffffa1dbb44c>] ? extent_io_exit+0x5c/0x100 [btrfs] [<ffffffffa1df563a>] ? exit_btrfs_fs+0x1d/0x3f [btrfs] [<ffffffff810bc664>] ? sys_delete_module+0x194/0x260 [<ffffffff810e53a7>] ? audit_syscall_entry+0x1d7/0x200 [<ffffffff8100b072>] ? system_call_fastpath+0x16/0x1b
The tech preview of btrfs in RHEL6 is being ended. Red Hat will not be providing any further updates or security fixes for btrfs in RHEL6, therefore this bug is being closed as "WONTFIX". The tech preview of btrfs in RHEL7 is continuing, and an update will be provided in RHEL 7.1, in due course. If you are interested in the btrfs tech preview in RHEL7, then please do get in touch to share your use case(s) via the normal channels (e.g. your partner manager, TAM or via a support ticket depending upon which is most approporiate). We are very keen to collect as much information as we can about use cases for btrfs and other future developments in filesystems/storage.