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    SubjectRe: Missing exports(patch) + Ugh
    Itai Nahshon wrote:
    > After adding these (and the fix to SHM_SWP_TYPE) I get Ugh messages
    > when I try to use an ide cdrom with ide-scsi and the scsi cdrom driver.
    > The Ugh messages are always from the lock_kernel() inlined call in the
    > next system call after the call to open /dev/scd0.
    > In some cases (I'm not sure it is releted) I got a system hang
    > when repeating the same scenario.
    > To repeat:
    > compile support for ide-scsi and scsi cdrom as modules, then
    > rmmod ide-cd, modprobe ide-scsi, modprobe sr_mod, run this program:
    > main() {
    > int fd;
    > char buf[2048];
    > fd = open("/dev/scd0", 0);
    > read(fd, buf, 2048);
    > }

    I think I located the reason for the Ugh in the scsi cdrom driver.
    do_sr_request() (in drivers/cdrom/sr.c).

    The function is starting with

    But later uses the macro INIT_SCSI_REQUEST:
    #define INIT_SCSI_REQUEST \
    if (!CURRENT) { \
    spin_unlock_irqrestore(&current_lock,flags); \
    return; \

    Which does not reset global_irq_holder (when __SMP__ is defined).

    Notice also that if the host is "in_recovery" that same function returns
    without re-enabling interrupts.

    Itai Nahshon

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      Last update: 2005-03-22 13:41    [W:0.020 / U:10.536 seconds]
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