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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-06-02 12:29:03 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-06-02 12:29:03 -0700 |
commit | e6e6d074369c839e84071c3b056adf20ead8da6e (patch) | |
tree | ef2cb726f59090d54d1c6c163587fb52abed5e53 /fs | |
parent | b939c51445f0542e80a8f910014c418d04b5de6e (diff) | |
parent | 63db7c815bc0997c29e484d2409684fdd9fcd93b (diff) | |
download | linux-e6e6d074369c839e84071c3b056adf20ead8da6e.tar.bz2 |
Merge tag 'xfs-4.12-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull XFS fix from Darrick Wong:
"I've one more bugfix for you for 4.12-rc4: Fix an unmount hang due to
a race in io buffer accounting"
* tag 'xfs-4.12-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: use ->b_state to fix buffer I/O accounting release race
Diffstat (limited to 'fs')
-rw-r--r-- | fs/xfs/xfs_buf.c | 38 | ||||
-rw-r--r-- | fs/xfs/xfs_buf.h | 5 |
2 files changed, 28 insertions, 15 deletions
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index 62fa39276a24..07b77b73b024 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -97,12 +97,16 @@ static inline void xfs_buf_ioacct_inc( struct xfs_buf *bp) { - if (bp->b_flags & (XBF_NO_IOACCT|_XBF_IN_FLIGHT)) + if (bp->b_flags & XBF_NO_IOACCT) return; ASSERT(bp->b_flags & XBF_ASYNC); - bp->b_flags |= _XBF_IN_FLIGHT; - percpu_counter_inc(&bp->b_target->bt_io_count); + spin_lock(&bp->b_lock); + if (!(bp->b_state & XFS_BSTATE_IN_FLIGHT)) { + bp->b_state |= XFS_BSTATE_IN_FLIGHT; + percpu_counter_inc(&bp->b_target->bt_io_count); + } + spin_unlock(&bp->b_lock); } /* @@ -110,14 +114,24 @@ xfs_buf_ioacct_inc( * freed and unaccount from the buftarg. */ static inline void -xfs_buf_ioacct_dec( +__xfs_buf_ioacct_dec( struct xfs_buf *bp) { - if (!(bp->b_flags & _XBF_IN_FLIGHT)) - return; + ASSERT(spin_is_locked(&bp->b_lock)); - bp->b_flags &= ~_XBF_IN_FLIGHT; - percpu_counter_dec(&bp->b_target->bt_io_count); + if (bp->b_state & XFS_BSTATE_IN_FLIGHT) { + bp->b_state &= ~XFS_BSTATE_IN_FLIGHT; + percpu_counter_dec(&bp->b_target->bt_io_count); + } +} + +static inline void +xfs_buf_ioacct_dec( + struct xfs_buf *bp) +{ + spin_lock(&bp->b_lock); + __xfs_buf_ioacct_dec(bp); + spin_unlock(&bp->b_lock); } /* @@ -149,9 +163,9 @@ xfs_buf_stale( * unaccounted (released to LRU) before that occurs. Drop in-flight * status now to preserve accounting consistency. */ - xfs_buf_ioacct_dec(bp); - spin_lock(&bp->b_lock); + __xfs_buf_ioacct_dec(bp); + atomic_set(&bp->b_lru_ref, 0); if (!(bp->b_state & XFS_BSTATE_DISPOSE) && (list_lru_del(&bp->b_target->bt_lru, &bp->b_lru))) @@ -979,12 +993,12 @@ xfs_buf_rele( * ensures the decrement occurs only once per-buf. */ if ((atomic_read(&bp->b_hold) == 1) && !list_empty(&bp->b_lru)) - xfs_buf_ioacct_dec(bp); + __xfs_buf_ioacct_dec(bp); goto out_unlock; } /* the last reference has been dropped ... */ - xfs_buf_ioacct_dec(bp); + __xfs_buf_ioacct_dec(bp); if (!(bp->b_flags & XBF_STALE) && atomic_read(&bp->b_lru_ref)) { /* * If the buffer is added to the LRU take a new reference to the diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h index 8d1d44f87ce9..1508121f29f2 100644 --- a/fs/xfs/xfs_buf.h +++ b/fs/xfs/xfs_buf.h @@ -63,7 +63,6 @@ typedef enum { #define _XBF_KMEM (1 << 21)/* backed by heap memory */ #define _XBF_DELWRI_Q (1 << 22)/* buffer on a delwri queue */ #define _XBF_COMPOUND (1 << 23)/* compound buffer */ -#define _XBF_IN_FLIGHT (1 << 25) /* I/O in flight, for accounting purposes */ typedef unsigned int xfs_buf_flags_t; @@ -84,14 +83,14 @@ typedef unsigned int xfs_buf_flags_t; { _XBF_PAGES, "PAGES" }, \ { _XBF_KMEM, "KMEM" }, \ { _XBF_DELWRI_Q, "DELWRI_Q" }, \ - { _XBF_COMPOUND, "COMPOUND" }, \ - { _XBF_IN_FLIGHT, "IN_FLIGHT" } + { _XBF_COMPOUND, "COMPOUND" } /* * Internal state flags. */ #define XFS_BSTATE_DISPOSE (1 << 0) /* buffer being discarded */ +#define XFS_BSTATE_IN_FLIGHT (1 << 1) /* I/O in flight */ /* * The xfs_buftarg contains 2 notions of "sector size" - |