Avoid that checkpatch reports the following:
WARNING: Possible unnecessary 'out of memory' message
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@6106 d57e44dd-8a1f-0410-8b47-8ef2f437770f
For some filesystems, e.g. tmpfs, address_space.readpage is NULL.
Disable zero-copy reading for such filesystems. See also shmem_aops
in mm/shmem.c. See also inode_init_always() and empty_aops in fs/inode.c.
This patch avoids that the following call trace is triggered:
BUG: unable to handle kernel NULL pointer dereference at (null)
Call Trace:
[<ffffffffa0547d66>] prepare_read+0x106/0x1d0 [scst_vdisk]
[<ffffffffa0547f20>] fileio_alloc_data_buf+0xf0/0x330 [scst_vdisk]
[<ffffffffa046fc9b>] scst_prepare_space+0x9b/0x6e0 [scst]
[<ffffffffa047d4d5>] scst_process_active_cmd+0x545/0x840 [scst]
[<ffffffffa047dad2>] scst_cmd_init_done+0x302/0x5d0 [scst]
[<ffffffffa0563ab2>] scst_cmd_init_stage1_done.constprop.37+0x12/0x20 [iscsi_scst]
[<ffffffffa056a9ea>] scsi_cmnd_start+0x25a/0x550 [iscsi_scst]
[<ffffffffa056b4a8>] cmnd_rx_start+0x148/0x1a0 [iscsi_scst]
[<ffffffffa056e4f8>] process_read_io+0x3b8/0x800 [iscsi_scst]
[<ffffffffa056ea07>] scst_do_job_rd+0xc7/0x220 [iscsi_scst]
[<ffffffffa056efed>] istrd+0x16d/0x2e0 [iscsi_scst]
[<ffffffff81079efd>] kthread+0xed/0x110
[<ffffffff817227fc>] ret_from_fork+0x7c/0xb0
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5988 d57e44dd-8a1f-0410-8b47-8ef2f437770f
Avoid that the static source code analysis tool 'smatch' reports
the following warning:
vdisk_unmap_range() warn: should 'blocks << cmd->dev->block_shift' be a 64 bit type?
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5987 d57e44dd-8a1f-0410-8b47-8ef2f437770f
This patch does not change any behavior but micro-optimizes
vdisk_caching_pg(). Declaring the array caching_pg[] const reduces
11 bytes from the assembler code of this function.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5986 d57e44dd-8a1f-0410-8b47-8ef2f437770f
Avoid that checkpatch v3.18 reports the following warning for these
two macros:
WARNING: Macros with flow control statements should be avoided
This patch does not change any functionality.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5985 d57e44dd-8a1f-0410-8b47-8ef2f437770f
scsi_setup_cmnd() sets sc_data_direction to DMA_TO_DEVICE for bidirectional
commands. Hence test SCpnt->request->next_rq instead of sc_data_direction
to figure out whether or not a command is bidirectional.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5984 d57e44dd-8a1f-0410-8b47-8ef2f437770f
Changes in this patch:
- Rework the SCSI pass-through code such that for kernel versions
>= 2.6.30 the scst_exec_req_fifo patch is no longer needed.
- Modify the pass-through code such that blk_rq_append_bio() is only
called for kernel version 2.6.30. For later kernel versions
blk_make_request() is called instead.
- Rework scst_scsi_exec_async().
- Add debug tracing of SCSI pass-through result status.
- Add a lockdep_assert_held() call in scsi_end_async().
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@5979 d57e44dd-8a1f-0410-8b47-8ef2f437770f
