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| author | Miklos Szeredi <mszeredi@suse.cz> | 2015-01-06 10:45:35 +0100 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@suse.cz> | 2015-01-06 10:45:35 +0100 |
| commit | 9759bd51899458af4f4bcc11046f01285642ca10 (patch) | |
| tree | 9e50d89d7772cbff8a7502a19353c984a948d1a6 /fs | |
| parent | 21f621741a770c119e7529a3f5c0e6b7c91383a3 (diff) | |
| download | linux-9759bd51899458af4f4bcc11046f01285642ca10.tar.gz | |
fuse: add memory barrier to INIT
Theoretically we need to order setting of various fields in fc with fc->initialized. No known bug reports related to this yet. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/fuse/dev.c | 15 | ||||
| -rw-r--r-- | fs/fuse/fuse_i.h | 2 | ||||
| -rw-r--r-- | fs/fuse/inode.c | 2 |
3 files changed, 16 insertions, 3 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index c847d6b225e2..ed19a7d622fa 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -131,6 +131,13 @@ static void fuse_req_init_context(struct fuse_req *req) req->in.h.pid = current->pid; } +void fuse_set_initialized(struct fuse_conn *fc) +{ + /* Make sure stores before this are seen on another CPU */ + smp_wmb(); + fc->initialized = 1; +} + static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background) { return !fc->initialized || (for_background && fc->blocked); @@ -155,6 +162,8 @@ static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages, if (intr) goto out; } + /* Matches smp_wmb() in fuse_set_initialized() */ + smp_rmb(); err = -ENOTCONN; if (!fc->connected) @@ -253,6 +262,8 @@ struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc, atomic_inc(&fc->num_waiting); wait_event(fc->blocked_waitq, fc->initialized); + /* Matches smp_wmb() in fuse_set_initialized() */ + smp_rmb(); req = fuse_request_alloc(0); if (!req) req = get_reserved_req(fc, file); @@ -2163,7 +2174,7 @@ void fuse_abort_conn(struct fuse_conn *fc) if (fc->connected) { fc->connected = 0; fc->blocked = 0; - fc->initialized = 1; + fuse_set_initialized(fc); end_io_requests(fc); end_queued_requests(fc); end_polls(fc); @@ -2182,7 +2193,7 @@ int fuse_dev_release(struct inode *inode, struct file *file) spin_lock(&fc->lock); fc->connected = 0; fc->blocked = 0; - fc->initialized = 1; + fuse_set_initialized(fc); end_queued_requests(fc); end_polls(fc); wake_up_all(&fc->blocked_waitq); diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index e0fc6725d1d0..1cdfb07c1376 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -906,4 +906,6 @@ int fuse_write_inode(struct inode *inode, struct writeback_control *wbc); int fuse_do_setattr(struct inode *inode, struct iattr *attr, struct file *file); +void fuse_set_initialized(struct fuse_conn *fc); + #endif /* _FS_FUSE_I_H */ diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 6a20f2ff2c2e..f38256e4476e 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -897,7 +897,7 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) fc->max_write = max_t(unsigned, 4096, fc->max_write); fc->conn_init = 1; } - fc->initialized = 1; + fuse_set_initialized(fc); wake_up_all(&fc->blocked_waitq); } |