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| author | Goldwyn Rodrigues <rgoldwyn@suse.com> | 2020-09-28 08:51:08 -0700 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2020-09-28 08:51:08 -0700 |
| commit | 1a31182edd0083bb9f26e582ed39f92f898c4d0a (patch) | |
| tree | 8bbfb19660649ede924df743a4cc1db1ed645b02 /fs | |
| parent | c3d4ed1abecfcfc801199cfadb71f5b80e025d9e (diff) | |
| download | lwn-1a31182edd0083bb9f26e582ed39f92f898c4d0a.tar.gz lwn-1a31182edd0083bb9f26e582ed39f92f898c4d0a.zip | |
iomap: Call inode_dio_end() before generic_write_sync()
iomap complete routine can deadlock with btrfs_fallocate because of the
call to generic_write_sync().
P0 P1
inode_lock() fallocate(FALLOC_FL_ZERO_RANGE)
__iomap_dio_rw() inode_lock()
<block>
<submits IO>
<completes IO>
inode_unlock()
<gets inode_lock()>
inode_dio_wait()
iomap_dio_complete()
generic_write_sync()
btrfs_file_fsync()
inode_lock()
<deadlock>
inode_dio_end() is used to notify the end of DIO data in order
to synchronize with truncate. Call inode_dio_end() before calling
generic_write_sync(), so filesystems can lock i_rwsem during a sync.
This matches the way it is done in fs/direct-io.c:dio_complete().
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
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/iomap/direct-io.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index b005ef5f554e..933f234d5bec 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -118,6 +118,7 @@ ssize_t iomap_dio_complete(struct iomap_dio *dio) dio_warn_stale_pagecache(iocb->ki_filp); } + inode_dio_end(file_inode(iocb->ki_filp)); /* * If this is a DSYNC write, make sure we push it to stable storage now * that we've written data. @@ -125,7 +126,6 @@ ssize_t iomap_dio_complete(struct iomap_dio *dio) if (ret > 0 && (dio->flags & IOMAP_DIO_NEED_SYNC)) ret = generic_write_sync(iocb, ret); - inode_dio_end(file_inode(iocb->ki_filp)); kfree(dio); return ret; |