io-wq: add support for inheriting ->fs

Some work items need this for relative path lookup, make it available
like the other inherited credentials/mm/etc.

Cc: stable@vger.kernel.org # 5.3+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2020-02-06 21:42:51 -07:00
parent faac996ccd
commit 9392a27d88
2 changed files with 11 additions and 1 deletions

View File

@ -16,6 +16,7 @@
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/rculist_nulls.h>
#include <linux/fs_struct.h>
#include "io-wq.h"
@ -59,6 +60,7 @@ struct io_worker {
const struct cred *cur_creds;
const struct cred *saved_creds;
struct files_struct *restore_files;
struct fs_struct *restore_fs;
};
#if BITS_PER_LONG == 64
@ -151,6 +153,9 @@ static bool __io_worker_unuse(struct io_wqe *wqe, struct io_worker *worker)
task_unlock(current);
}
if (current->fs != worker->restore_fs)
current->fs = worker->restore_fs;
/*
* If we have an active mm, we need to drop the wq lock before unusing
* it. If we do, return true and let the caller retry the idle loop.
@ -311,6 +316,7 @@ static void io_worker_start(struct io_wqe *wqe, struct io_worker *worker)
worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING);
worker->restore_files = current->files;
worker->restore_fs = current->fs;
io_wqe_inc_running(wqe, worker);
}
@ -481,6 +487,8 @@ next:
current->files = work->files;
task_unlock(current);
}
if (work->fs && current->fs != work->fs)
current->fs = work->fs;
if (work->mm != worker->mm)
io_wq_switch_mm(worker, work);
if (worker->cur_creds != work->creds)

View File

@ -74,6 +74,7 @@ struct io_wq_work {
struct files_struct *files;
struct mm_struct *mm;
const struct cred *creds;
struct fs_struct *fs;
unsigned flags;
};
@ -81,10 +82,11 @@ struct io_wq_work {
do { \
(work)->list.next = NULL; \
(work)->func = _func; \
(work)->flags = 0; \
(work)->files = NULL; \
(work)->mm = NULL; \
(work)->creds = NULL; \
(work)->fs = NULL; \
(work)->flags = 0; \
} while (0) \
typedef void (get_work_fn)(struct io_wq_work *);