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authorBoaz Harrosh <bharrosh@panasas.com>2009-12-01 17:36:21 +0200
committerJames Bottomley <James.Bottomley@suse.de>2009-12-10 08:54:17 -0600
commit5d0961fd1f25e117f907f3af3aaa870637049252 (patch)
tree1eb877e773c511b3da68cab9da4ae0d0e0ee7369 /include/scsi
parentaeab3fd7b865bc4086a80a83cfdd67dded3b41a0 (diff)
downloadlinux-linaro-android-5d0961fd1f25e117f907f3af3aaa870637049252.tar.gz
[SCSI] libosd: Fix blk_put_request locking again
So libosd has decided to sacrifice some code simplicity for the sake of a clean API. One of these things is the possibility for users to call osd_end_request, in any condition at any state. This opens up some problems with calling blk_put_request when out-side of the completion callback but calling __blk_put_request when detecting a from-completion state. The current hack was working just fine until exofs decided to operate on all devices in parallel and wait for the sum of the requests, before deallocating all osd-requests at once. There are two new possible cases 1. All request in a group are deallocated as part of the last request's async-done, request_queue is locked. 2. All request in a group where executed asynchronously, but de-allocation was delayed to after the async-done, in the context of another thread. Async execution but request_queue is not locked. The solution I chose was to separate the deallocation of the osd_request which has the information users need, from the deallocation of the internal(2) requests which impose the locking problem. The internal block-requests are freed unconditionally inside the async-done-callback, when we know the queue is always locked. If at osd_end_request time we still have a bock-request, then we know it did not come from within an async-done-callback and we can call the regular blk_put_request. The internal requests were used for carrying error information after execution. This information is now copied to osd_request members for later analysis by user code. The external API and behaviour was unchanged, except now it really supports what was previously advertised. Reported-by: Vineet Agarwal <checkout.vineet@gmail.com> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Cc: Stable Tree <stable@kernel.org> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Diffstat (limited to 'include/scsi')
-rw-r--r--include/scsi/osd_initiator.h5
1 files changed, 3 insertions, 2 deletions
diff --git a/include/scsi/osd_initiator.h b/include/scsi/osd_initiator.h
index 39d6d109715..a8f37012663 100644
--- a/include/scsi/osd_initiator.h
+++ b/include/scsi/osd_initiator.h
@@ -142,6 +142,7 @@ struct osd_request {
struct _osd_io_info {
struct bio *bio;
u64 total_bytes;
+ u64 residual;
struct request *req;
struct _osd_req_data_segment *last_seg;
u8 *pad_buff;
@@ -150,12 +151,14 @@ struct osd_request {
gfp_t alloc_flags;
unsigned timeout;
unsigned retries;
+ unsigned sense_len;
u8 sense[OSD_MAX_SENSE_LEN];
enum osd_attributes_mode attributes_mode;
osd_req_done_fn *async_done;
void *async_private;
int async_error;
+ int req_errors;
};
static inline bool osd_req_is_ver1(struct osd_request *or)
@@ -297,8 +300,6 @@ enum osd_err_priority {
};
struct osd_sense_info {
- u64 out_resid; /* Zero on success otherwise out residual */
- u64 in_resid; /* Zero on success otherwise in residual */
enum osd_err_priority osd_err_pri;
int key; /* one of enum scsi_sense_keys */