[PATCH 09/12] gfs2: hold i_rwsem until AIO completes
From: Christoph Hellwig <hch@lst.de>
Date: 2020-01-14 16:13:11
Also in:
linux-fsdevel, linux-mm, linux-xfs, lkml
Subsystem:
filesystems (vfs and infrastructure), gfs2 file system, the rest · Maintainers:
Alexander Viro, Christian Brauner, Andreas Gruenbacher, Linus Torvalds
Switch gfs from the magic i_dio_count scheme to just hold i_rwsem until the actual I/O has completed to reduce the locking complexity and avoid nasty bugs due to missing inode_dio_wait calls. Note that gfs only uses i_rwsem for direct I/O writes, not for reads so no change to the read behavior. It might also make sense to use the same scheme for the gfs2 internal cluster lock. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/gfs2/bmap.c | 2 -- fs/gfs2/file.c | 6 ++++-- fs/gfs2/glops.c | 10 ++-------- 3 files changed, 6 insertions(+), 12 deletions(-)
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 08f6fbb3655e..226f4eb680c7 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c@@ -2181,8 +2181,6 @@ int gfs2_setattr_size(struct inode *inode, u64 newsize) if (ret) return ret; - inode_dio_wait(inode); - ret = gfs2_rsqa_alloc(ip); if (ret) goto out;
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 2260cb5d31af..82a2f313a3e6 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c@@ -806,7 +806,8 @@ static ssize_t gfs2_file_direct_write(struct kiocb *iocb, struct iov_iter *from) if (offset + len > i_size_read(&ip->i_inode)) goto out; - ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL, 0); + ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL, + IOMAP_DIO_RWSEM_EXCL); out: gfs2_glock_dq(&gh);
@@ -923,7 +924,8 @@ static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from) return generic_write_sync(iocb, ret); out_unlock: - inode_unlock(inode); + if (ret != -EIOCBQUEUED) + inode_unlock(inode); return ret; }
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index 4ede1f18de85..a705eeb75117 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c@@ -243,11 +243,8 @@ static void inode_go_sync(struct gfs2_glock *gl) struct address_space *metamapping = gfs2_glock2aspace(gl); int error; - if (isreg) { - if (test_and_clear_bit(GIF_SW_PAGED, &ip->i_flags)) - unmap_shared_mapping_range(ip->i_inode.i_mapping, 0, 0); - inode_dio_wait(&ip->i_inode); - } + if (isreg && test_and_clear_bit(GIF_SW_PAGED, &ip->i_flags)) + unmap_shared_mapping_range(ip->i_inode.i_mapping, 0, 0); if (!test_and_clear_bit(GLF_DIRTY, &gl->gl_flags)) goto out;
@@ -440,9 +437,6 @@ static int inode_go_lock(struct gfs2_holder *gh) return error; } - if (gh->gh_state != LM_ST_DEFERRED) - inode_dio_wait(&ip->i_inode); - if ((ip->i_diskflags & GFS2_DIF_TRUNC_IN_PROG) && (gl->gl_state == LM_ST_EXCLUSIVE) && (gh->gh_state == LM_ST_EXCLUSIVE)) {
--
2.24.1