• Tomas Henzl's avatar
    block: fix ext_devt_idr handling · 7b74e912
    Tomas Henzl authored
    While adding and removing a lot of disks disks and partitions this
    sometimes shows up:
    
      WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xc9/0x130() (Not tainted)
      Hardware name:
      sysfs: cannot create duplicate filename '/dev/block/259:751'
      Modules linked in: raid1 autofs4 bnx2fc cnic uio fcoe libfcoe libfc 8021q scsi_transport_fc scsi_tgt garp stp llc sunrpc cpufreq_ondemand powernow_k8 freq_table mperf ipv6 dm_mirror dm_region_hash dm_log power_meter microcode dcdbas serio_raw amd64_edac_mod edac_core edac_mce_amd i2c_piix4 i2c_core k10temp bnx2 sg ixgbe dca mdio ext4 mbcache jbd2 dm_round_robin sr_mod cdrom sd_mod crc_t10dif ata_generic pata_acpi pata_atiixp ahci mptsas mptscsih mptbase scsi_transport_sas dm_multipath dm_mod [last unloaded: scsi_wait_scan]
      Pid: 44103, comm: async/16 Not tainted 2.6.32-195.el6.x86_64 #1
      Call Trace:
        warn_slowpath_common+0x87/0xc0
        warn_slowpath_fmt+0x46/0x50
        sysfs_add_one+0xc9/0x130
        sysfs_do_create_link+0x12b/0x170
        sysfs_create_link+0x13/0x20
        device_add+0x317/0x650
        idr_get_new+0x13/0x50
        add_partition+0x21c/0x390
        rescan_partitions+0x32b/0x470
        sd_open+0x81/0x1f0 [sd_mod]
        __blkdev_get+0x1b6/0x3c0
        blkdev_get+0x10/0x20
        register_disk+0x155/0x170
        add_disk+0xa6/0x160
        sd_probe_async+0x13b/0x210 [sd_mod]
        add_wait_queue+0x46/0x60
        async_thread+0x102/0x250
        default_wake_function+0x0/0x20
        async_thread+0x0/0x250
        kthread+0x96/0xa0
        child_rip+0xa/0x20
        kthread+0x0/0xa0
        child_rip+0x0/0x20
    
    This most likely happens because dev_t is freed while the number is
    still used and idr_get_new() is not protected on every use.  The fix
    adds a mutex where it wasn't before and moves the dev_t free function so
    it is called after device del.
    Signed-off-by: default avatarTomas Henzl <thenzl@redhat.com>
    Cc: Jens Axboe <axboe@kernel.dk>
    Cc: <stable@vger.kernel.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    7b74e912
genhd.c 44.2 KB