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authorJens Axboe <axboe@kernel.dk>2020-02-07 16:05:21 -0700
committerJens Axboe <axboe@kernel.dk>2020-02-08 13:07:00 -0700
commitff002b30181d30cdfbca316dadd099c3ca0d739c (patch)
treeba32d4f78d1a059383fff73d3f36156ef1beb721 /fs/io_uring.c
parent9392a27d88b9707145d713654eb26f0c29789e50 (diff)
downloadlinux-ff002b30181d30cdfbca316dadd099c3ca0d739c.tar.bz2
io_uring: grab ->fs as part of async preparation
This passes it in to io-wq, so it assumes the right fs_struct when executing async work that may need to do lookups. Cc: stable@vger.kernel.org # 5.3+ Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/io_uring.c')
-rw-r--r--fs/io_uring.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 1a3ca6577a10..2a7bb178986e 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -75,6 +75,7 @@
#include <linux/fsnotify.h>
#include <linux/fadvise.h>
#include <linux/eventpoll.h>
+#include <linux/fs_struct.h>
#define CREATE_TRACE_POINTS
#include <trace/events/io_uring.h>
@@ -611,6 +612,8 @@ struct io_op_def {
unsigned not_supported : 1;
/* needs file table */
unsigned file_table : 1;
+ /* needs ->fs */
+ unsigned needs_fs : 1;
};
static const struct io_op_def io_op_defs[] = {
@@ -653,12 +656,14 @@ static const struct io_op_def io_op_defs[] = {
.needs_mm = 1,
.needs_file = 1,
.unbound_nonreg_file = 1,
+ .needs_fs = 1,
},
[IORING_OP_RECVMSG] = {
.async_ctx = 1,
.needs_mm = 1,
.needs_file = 1,
.unbound_nonreg_file = 1,
+ .needs_fs = 1,
},
[IORING_OP_TIMEOUT] = {
.async_ctx = 1,
@@ -689,6 +694,7 @@ static const struct io_op_def io_op_defs[] = {
.needs_file = 1,
.fd_non_neg = 1,
.file_table = 1,
+ .needs_fs = 1,
},
[IORING_OP_CLOSE] = {
.needs_file = 1,
@@ -702,6 +708,7 @@ static const struct io_op_def io_op_defs[] = {
.needs_mm = 1,
.needs_file = 1,
.fd_non_neg = 1,
+ .needs_fs = 1,
},
[IORING_OP_READ] = {
.needs_mm = 1,
@@ -733,6 +740,7 @@ static const struct io_op_def io_op_defs[] = {
.needs_file = 1,
.fd_non_neg = 1,
.file_table = 1,
+ .needs_fs = 1,
},
[IORING_OP_EPOLL_CTL] = {
.unbound_nonreg_file = 1,
@@ -907,6 +915,16 @@ static inline void io_req_work_grab_env(struct io_kiocb *req,
}
if (!req->work.creds)
req->work.creds = get_current_cred();
+ if (!req->work.fs && def->needs_fs) {
+ spin_lock(&current->fs->lock);
+ if (!current->fs->in_exec) {
+ req->work.fs = current->fs;
+ req->work.fs->users++;
+ } else {
+ req->work.flags |= IO_WQ_WORK_CANCEL;
+ }
+ spin_unlock(&current->fs->lock);
+ }
}
static inline void io_req_work_drop_env(struct io_kiocb *req)
@@ -919,6 +937,16 @@ static inline void io_req_work_drop_env(struct io_kiocb *req)
put_cred(req->work.creds);
req->work.creds = NULL;
}
+ if (req->work.fs) {
+ struct fs_struct *fs = req->work.fs;
+
+ spin_lock(&req->work.fs->lock);
+ if (--fs->users)
+ fs = NULL;
+ spin_unlock(&req->work.fs->lock);
+ if (fs)
+ free_fs_struct(fs);
+ }
}
static inline bool io_prep_async_work(struct io_kiocb *req,