summaryrefslogtreecommitdiffstats
path: root/fs/sysfs/file.c
diff options
context:
space:
mode:
authorJens Axboe <axboe@kernel.dk>2013-12-31 09:51:02 -0700
committerJens Axboe <axboe@kernel.dk>2013-12-31 09:51:02 -0700
commitb28bc9b38c52f63f43e3fd875af982f2240a2859 (patch)
tree76cdb7b52b58f5685993cc15ed81d1c903023358 /fs/sysfs/file.c
parent8d30726912cb39c3a3ebde06214d54861f8fdde2 (diff)
parent802eee95bde72fd0cd0f3a5b2098375a487d1eda (diff)
Merge tag 'v3.13-rc6' into for-3.14/core
Needed to bring blk-mq uptodate, since changes have been going in since for-3.14/core was established. Fixup merge issues related to the immutable biovec changes. Signed-off-by: Jens Axboe <axboe@kernel.dk> Conflicts: block/blk-flush.c fs/btrfs/check-integrity.c fs/btrfs/extent_io.c fs/btrfs/scrub.c fs/logfs/dev_bdev.c
Diffstat (limited to 'fs/sysfs/file.c')
-rw-r--r--fs/sysfs/file.c18
1 files changed, 17 insertions, 1 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 79b5da2acbe..35e7d08fe62 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -649,7 +649,23 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
if (!of)
goto err_out;
- mutex_init(&of->mutex);
+ /*
+ * The following is done to give a different lockdep key to
+ * @of->mutex for files which implement mmap. This is a rather
+ * crude way to avoid false positive lockdep warning around
+ * mm->mmap_sem - mmap nests @of->mutex under mm->mmap_sem and
+ * reading /sys/block/sda/trace/act_mask grabs sr_mutex, under
+ * which mm->mmap_sem nests, while holding @of->mutex. As each
+ * open file has a separate mutex, it's okay as long as those don't
+ * happen on the same file. At this point, we can't easily give
+ * each file a separate locking class. Let's differentiate on
+ * whether the file is bin or not for now.
+ */
+ if (sysfs_is_bin(attr_sd))
+ mutex_init(&of->mutex);
+ else
+ mutex_init(&of->mutex);
+
of->sd = attr_sd;
of->file = file;