Backport from ml:
commit dc00809a53edd15369906b90407a2d5b976289f5
Author: Miklos Szeredi <[email protected]>
Date: Wed Jul 1 16:25:58 2015 +0200
fuse: use per req lock for lock/unlock_request()
Reuse req->waitq.lock for protecting FR_ABORTED and FR_LOCKED flags.
Signed-off-by: Miklos Szeredi <[email protected]>
Reviewed-by: Ashish Samant <[email protected]>
Signed-off-by: Maxim Patlasov <[email protected]>
---
fs/fuse/dev.c | 41 ++++++++++++++++++++---------------------
fs/fuse/fuse_i.h | 4 ++++
2 files changed, 24 insertions(+), 21 deletions(-)
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 29931bd..6d7db48 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -598,16 +598,16 @@ void fuse_force_forget(struct file *file, u64 nodeid)
* anything that could cause a page-fault. If the request was already
* aborted bail out.
*/
-static int lock_request(struct fuse_conn *fc, struct fuse_req *req)
+static int lock_request(struct fuse_req *req)
{
int err = 0;
if (req) {
- spin_lock(&fc->lock);
+ spin_lock(&req->waitq.lock);
if (test_bit(FR_ABORTED, &req->flags))
err = -ENOENT;
else
set_bit(FR_LOCKED, &req->flags);
- spin_unlock(&fc->lock);
+ spin_unlock(&req->waitq.lock);
}
return err;
}
@@ -616,22 +616,21 @@ static int lock_request(struct fuse_conn *fc, struct
fuse_req *req)
* Unlock request. If it was aborted while locked, caller is responsible
* for unlocking and ending the request.
*/
-static int unlock_request(struct fuse_conn *fc, struct fuse_req *req)
+static int unlock_request(struct fuse_req *req)
{
int err = 0;
if (req) {
- spin_lock(&fc->lock);
+ spin_lock(&req->waitq.lock);
if (test_bit(FR_ABORTED, &req->flags))
err = -ENOENT;
else
clear_bit(FR_LOCKED, &req->flags);
- spin_unlock(&fc->lock);
+ spin_unlock(&req->waitq.lock);
}
return err;
}
struct fuse_copy_state {
- struct fuse_conn *fc;
int write;
struct fuse_req *req;
const struct iovec *iov;
@@ -648,12 +647,10 @@ struct fuse_copy_state {
unsigned move_pages:1;
};
-static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc,
- int write,
+static void fuse_copy_init(struct fuse_copy_state *cs, int write,
const struct iovec *iov, unsigned long nr_segs)
{
memset(cs, 0, sizeof(*cs));
- cs->fc = fc;
cs->write = write;
cs->iov = iov;
cs->nr_segs = nr_segs;
@@ -693,7 +690,7 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
unsigned long offset;
int err;
- err = unlock_request(cs->fc, cs->req);
+ err = unlock_request(cs->req);
if (err)
return err;
@@ -754,7 +751,7 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
cs->addr += cs->len;
}
- return lock_request(cs->fc, cs->req);
+ return lock_request(cs->req);
}
/* Do as much copy to/from userspace buffer as we can */
@@ -800,7 +797,7 @@ static int fuse_try_move_page(struct fuse_copy_state *cs,
struct page **pagep)
struct page *newpage;
struct pipe_buffer *buf = cs->pipebufs;
- err = unlock_request(cs->fc, cs->req);
+ err = unlock_request(cs->req);
if (err)
return err;
@@ -857,12 +854,12 @@ static int fuse_try_move_page(struct fuse_copy_state *cs,
struct page **pagep)
lru_cache_add_file(newpage);
err = 0;
- spin_lock(&cs->fc->lock);
+ spin_lock(&cs->req->waitq.lock);
if (test_bit(FR_ABORTED, &cs->req->flags))
err = -ENOENT;
else
*pagep = newpage;
- spin_unlock(&cs->fc->lock);
+ spin_unlock(&cs->req->waitq.lock);
if (err) {
unlock_page(newpage);
@@ -882,7 +879,7 @@ out_fallback:
cs->mapaddr = buf->ops->map(cs->pipe, buf, 1);
cs->buf = cs->mapaddr + buf->offset;
- err = lock_request(cs->fc, cs->req);
+ err = lock_request(cs->req);
if (err)
return err;
@@ -898,7 +895,7 @@ static int fuse_ref_page(struct fuse_copy_state *cs, struct
page *page,
if (cs->nr_segs == cs->pipe->buffers)
return -EIO;
- err = unlock_request(cs->fc, cs->req);
+ err = unlock_request(cs->req);
if (err)
return err;
@@ -1320,7 +1317,7 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const
struct iovec *iov,
if (!fc)
return -EPERM;
- fuse_copy_init(&cs, fc, 1, iov, nr_segs);
+ fuse_copy_init(&cs, 1, iov, nr_segs);
return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
}
@@ -1358,7 +1355,7 @@ static ssize_t fuse_dev_splice_read(struct file *in,
loff_t *ppos,
if (!bufs)
return -ENOMEM;
- fuse_copy_init(&cs, fc, 1, NULL, 0);
+ fuse_copy_init(&cs, 1, NULL, 0);
cs.pipebufs = bufs;
cs.pipe = pipe;
ret = fuse_dev_do_read(fc, in, &cs, len);
@@ -1965,7 +1962,7 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, const
struct iovec *iov,
if (!fc)
return -EPERM;
- fuse_copy_init(&cs, fc, 0, iov, nr_segs);
+ fuse_copy_init(&cs, 0, iov, nr_segs);
return fuse_dev_do_write(fc, &cs, iov_length(iov, nr_segs));
}
@@ -2030,7 +2027,7 @@ static ssize_t fuse_dev_splice_write(struct
pipe_inode_info *pipe,
}
pipe_unlock(pipe);
- fuse_copy_init(&cs, fc, 0, NULL, nbuf);
+ fuse_copy_init(&cs, 0, NULL, nbuf);
cs.pipebufs = bufs;
cs.pipe = pipe;
@@ -2104,9 +2101,11 @@ __acquires(fc->lock)
list_for_each_entry_safe(req, next, &fc->io, list) {
req->out.h.error = -ECONNABORTED;
+ spin_lock(&req->waitq.lock);
set_bit(FR_ABORTED, &req->flags);
if (!test_bit(FR_LOCKED, &req->flags))
list_move(&req->list, &to_end);
+ spin_unlock(&req->waitq.lock);
}
while (!list_empty(&to_end)) {
req = list_first_entry(&to_end, struct fuse_req, list);
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 31062a0..b96b6e7 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -306,6 +306,10 @@ enum fuse_req_flag {
/**
* A request to the client
+ *
+ * .waitq.lock protects the following fields:
+ * - FR_ABORTED
+ * - FR_LOCKED (may also be modified under fc->lock, tested under both)
*/
struct fuse_req {
/** This can be on either pending processing or io lists in
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