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| author | Jason Gunthorpe <jgg@nvidia.com> | 2020-08-18 15:05:14 +0300 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2020-08-27 08:38:13 -0300 |
| commit | 07e266a7753d952978f317aa2b206b4da4769567 (patch) | |
| tree | ee5ff2bc80acfb300e0be319b9c0e80c64abbb04 | |
| parent | ca2968c1efcbeb547906cf6211874ec881beafec (diff) | |
| download | linux-07e266a7753d952978f317aa2b206b4da4769567.tar.gz linux-07e266a7753d952978f317aa2b206b4da4769567.tar.bz2 linux-07e266a7753d952978f317aa2b206b4da4769567.zip | |
RDMA/ucma: Remove unnecessary locking of file->ctx_list in close
During the file_operations release function it is already not possible
that write() can be running concurrently, remove the extra locking
around the ctx_list.
Link: https://lore.kernel.org/r/20200818120526.702120-3-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
| -rw-r--r-- | drivers/infiniband/core/ucma.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c index 625168563443..9b019f31743d 100644 --- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -1824,12 +1824,17 @@ static int ucma_close(struct inode *inode, struct file *filp) struct ucma_file *file = filp->private_data; struct ucma_context *ctx, *tmp; - mutex_lock(&file->mut); + /* + * ctx_list can only be mutated under the write(), which is no longer + * possible, so no locking needed. + */ list_for_each_entry_safe(ctx, tmp, &file->ctx_list, list) { + xa_erase(&ctx_table, ctx->id); + + mutex_lock(&file->mut); ctx->destroying = 1; mutex_unlock(&file->mut); - xa_erase(&ctx_table, ctx->id); flush_workqueue(file->close_wq); /* At that step once ctx was marked as destroying and workqueue * was flushed we are safe from any inflights handlers that @@ -1849,9 +1854,7 @@ static int ucma_close(struct inode *inode, struct file *filp) } ucma_free_ctx(ctx); - mutex_lock(&file->mut); } - mutex_unlock(&file->mut); destroy_workqueue(file->close_wq); kfree(file); return 0; |