diff options
author | Brian Foster <bfoster@redhat.com> | 2018-07-11 22:26:34 -0700 |
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committer | Darrick J. Wong <darrick.wong@oracle.com> | 2018-07-11 22:26:34 -0700 |
commit | eaebb515f1a4728565c482b13dfb17273dc4ddc8 (patch) | |
tree | 34b9110e34670e122862e0451f3d46dea9251205 /fs | |
parent | 5fdd97944ee5ae0fcdd88227224d0c2c87aa6db9 (diff) | |
download | linux-stable-eaebb515f1a4728565c482b13dfb17273dc4ddc8.tar.gz linux-stable-eaebb515f1a4728565c482b13dfb17273dc4ddc8.tar.bz2 linux-stable-eaebb515f1a4728565c482b13dfb17273dc4ddc8.zip |
xfs: refactor buffer submission into a common helper
Sync and async buffer submission both do generally similar things
with a couple odd exceptions. Refactor the core buffer submission
code into a common helper to isolate buffer submission from
completion handling of synchronous buffer I/O.
This patch does not change behavior. It is a step towards support
for using synchronous buffer I/O via synchronous delwri queue
submission.
Designed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/xfs/xfs_buf.c | 85 | ||||
-rw-r--r-- | fs/xfs/xfs_trace.h | 1 |
2 files changed, 37 insertions, 49 deletions
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index e9c058e3761c..7b0f7c79cd62 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -1458,22 +1458,20 @@ _xfs_buf_ioapply( * a call to this function unless the caller holds an additional reference * itself. */ -void -xfs_buf_submit( +static int +__xfs_buf_submit( struct xfs_buf *bp) { trace_xfs_buf_submit(bp, _RET_IP_); ASSERT(!(bp->b_flags & _XBF_DELWRI_Q)); - ASSERT(bp->b_flags & XBF_ASYNC); /* on shutdown we stale and complete the buffer immediately */ if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) { xfs_buf_ioerror(bp, -EIO); bp->b_flags &= ~XBF_DONE; xfs_buf_stale(bp); - xfs_buf_ioend(bp); - return; + return -EIO; } if (bp->b_flags & XBF_WRITE) @@ -1483,22 +1481,13 @@ xfs_buf_submit( bp->b_io_error = 0; /* - * The caller's reference is released during I/O completion. - * This occurs some time after the last b_io_remaining reference is - * released, so after we drop our Io reference we have to have some - * other reference to ensure the buffer doesn't go away from underneath - * us. Take a direct reference to ensure we have safe access to the - * buffer until we are finished with it. - */ - xfs_buf_hold(bp); - - /* * Set the count to 1 initially, this will stop an I/O completion * callout which happens before we have started all the I/O from calling * xfs_buf_ioend too early. */ atomic_set(&bp->b_io_remaining, 1); - xfs_buf_ioacct_inc(bp); + if (bp->b_flags & XBF_ASYNC) + xfs_buf_ioacct_inc(bp); _xfs_buf_ioapply(bp); /* @@ -1507,14 +1496,39 @@ xfs_buf_submit( * that we don't return to the caller with completion still pending. */ if (atomic_dec_and_test(&bp->b_io_remaining) == 1) { - if (bp->b_error) + if (bp->b_error || !(bp->b_flags & XBF_ASYNC)) xfs_buf_ioend(bp); else xfs_buf_ioend_async(bp); } - xfs_buf_rele(bp); + return 0; +} + +void +xfs_buf_submit( + struct xfs_buf *bp) +{ + int error; + + ASSERT(bp->b_flags & XBF_ASYNC); + + /* + * The caller's reference is released during I/O completion. + * This occurs some time after the last b_io_remaining reference is + * released, so after we drop our Io reference we have to have some + * other reference to ensure the buffer doesn't go away from underneath + * us. Take a direct reference to ensure we have safe access to the + * buffer until we are finished with it. + */ + xfs_buf_hold(bp); + + error = __xfs_buf_submit(bp); + if (error) + xfs_buf_ioend(bp); + /* Note: it is not safe to reference bp now we've dropped our ref */ + xfs_buf_rele(bp); } /* @@ -1526,22 +1540,7 @@ xfs_buf_submit_wait( { int error; - trace_xfs_buf_submit_wait(bp, _RET_IP_); - - ASSERT(!(bp->b_flags & (_XBF_DELWRI_Q | XBF_ASYNC))); - - if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) { - xfs_buf_ioerror(bp, -EIO); - xfs_buf_stale(bp); - bp->b_flags &= ~XBF_DONE; - return -EIO; - } - - if (bp->b_flags & XBF_WRITE) - xfs_buf_wait_unpin(bp); - - /* clear the internal error state to avoid spurious errors */ - bp->b_io_error = 0; + ASSERT(!(bp->b_flags & XBF_ASYNC)); /* * For synchronous IO, the IO does not inherit the submitters reference @@ -1551,20 +1550,9 @@ xfs_buf_submit_wait( */ xfs_buf_hold(bp); - /* - * Set the count to 1 initially, this will stop an I/O completion - * callout which happens before we have started all the I/O from calling - * xfs_buf_ioend too early. - */ - atomic_set(&bp->b_io_remaining, 1); - _xfs_buf_ioapply(bp); - - /* - * make sure we run completion synchronously if it raced with us and is - * already complete. - */ - if (atomic_dec_and_test(&bp->b_io_remaining) == 1) - xfs_buf_ioend(bp); + error = __xfs_buf_submit(bp); + if (error) + goto out; /* wait for completion before gathering the error from the buffer */ trace_xfs_buf_iowait(bp, _RET_IP_); @@ -1572,6 +1560,7 @@ xfs_buf_submit_wait( trace_xfs_buf_iowait_done(bp, _RET_IP_); error = bp->b_error; +out: /* * all done now, we can release the hold that keeps the buffer * referenced for the entire IO. diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index 9d741571b61e..b668fc127aa7 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -310,7 +310,6 @@ DEFINE_BUF_EVENT(xfs_buf_hold); DEFINE_BUF_EVENT(xfs_buf_rele); DEFINE_BUF_EVENT(xfs_buf_iodone); DEFINE_BUF_EVENT(xfs_buf_submit); -DEFINE_BUF_EVENT(xfs_buf_submit_wait); DEFINE_BUF_EVENT(xfs_buf_lock); DEFINE_BUF_EVENT(xfs_buf_lock_done); DEFINE_BUF_EVENT(xfs_buf_trylock_fail); |