summaryrefslogtreecommitdiff
path: root/sound/soc/sof/intel/byt.c
diff options
context:
space:
mode:
authorDave Wysochanski <dwysocha@redhat.com>2019-10-23 05:02:33 -0400
committerSteve French <stfrench@microsoft.com>2019-10-24 21:35:04 -0500
commitd46b0da7a33dd8c99d969834f682267a45444ab3 (patch)
treef8db814544321af48a968439747c6c39a334de60 /sound/soc/sof/intel/byt.c
parent1a67c415965752879e2e9fad407bc44fc7f25f23 (diff)
cifs: Fix cifsInodeInfo lock_sem deadlock when reconnect occurs
There's a deadlock that is possible and can easily be seen with a test where multiple readers open/read/close of the same file and a disruption occurs causing reconnect. The deadlock is due a reader thread inside cifs_strict_readv calling down_read and obtaining lock_sem, and then after reconnect inside cifs_reopen_file calling down_read a second time. If in between the two down_read calls, a down_write comes from another process, deadlock occurs. CPU0 CPU1 ---- ---- cifs_strict_readv() down_read(&cifsi->lock_sem); _cifsFileInfo_put OR cifs_new_fileinfo down_write(&cifsi->lock_sem); cifs_reopen_file() down_read(&cifsi->lock_sem); Fix the above by changing all down_write(lock_sem) calls to down_write_trylock(lock_sem)/msleep() loop, which in turn makes the second down_read call benign since it will never block behind the writer while holding lock_sem. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Suggested-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed--by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Diffstat (limited to 'sound/soc/sof/intel/byt.c')
0 files changed, 0 insertions, 0 deletions