From 4af1a04176bdb4688aa14f6c10d1d5131c036a9d Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 15 Dec 2014 12:57:00 +1100 Subject: [PATCH] md: move GET_BITMAP_FILE ioctl out from mddev_lock. It makes more sense to report bitmap_info->file, rather than bitmap->file (the later is only available once the array is active). With that change, use mddev->lock to protect bitmap_info being set to NULL, and we can call get_bitmap_file() without taking the mutex. Signed-off-by: NeilBrown --- drivers/md/md.c | 58 +++++++++++++++++++++++++++---------------------- drivers/md/md.h | 1 + 2 files changed, 33 insertions(+), 26 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 72c44d337ee2..5a949166dac0 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -5292,8 +5292,11 @@ static int do_md_stop(struct mddev *mddev, int mode, bitmap_destroy(mddev); if (mddev->bitmap_info.file) { - fput(mddev->bitmap_info.file); + struct file *f = mddev->bitmap_info.file; + spin_lock(&mddev->lock); mddev->bitmap_info.file = NULL; + spin_unlock(&mddev->lock); + fput(f); } mddev->bitmap_info.offset = 0; @@ -5503,32 +5506,30 @@ static int get_bitmap_file(struct mddev *mddev, void __user * arg) { mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */ char *ptr; - int err = -ENOMEM; + int err; file = kmalloc(sizeof(*file), GFP_NOIO); - if (!file) - goto out; + return -ENOMEM; + err = 0; + spin_lock(&mddev->lock); /* bitmap disabled, zero the first byte and copy out */ - if (!mddev->bitmap || !mddev->bitmap->storage.file) { + if (!mddev->bitmap_info.file) file->pathname[0] = '\0'; - goto copy_out; - } - - ptr = d_path(&mddev->bitmap->storage.file->f_path, - file->pathname, sizeof(file->pathname)); - if (IS_ERR(ptr)) - goto out; - - memmove(file->pathname, ptr, - sizeof(file->pathname)-(ptr-file->pathname)); + else if ((ptr = d_path(&mddev->bitmap_info.file->f_path, + file->pathname, sizeof(file->pathname))), + IS_ERR(ptr)) + err = PTR_ERR(ptr); + else + memmove(file->pathname, ptr, + sizeof(file->pathname)-(ptr-file->pathname)); + spin_unlock(&mddev->lock); -copy_out: - err = 0; - if (copy_to_user(arg, file, sizeof(*file))) + if (err == 0 && + copy_to_user(arg, file, sizeof(*file))) err = -EFAULT; -out: + kfree(file); return err; } @@ -5900,9 +5901,13 @@ static int set_bitmap_file(struct mddev *mddev, int fd) mddev->pers->quiesce(mddev, 0); } if (fd < 0) { - if (mddev->bitmap_info.file) - fput(mddev->bitmap_info.file); - mddev->bitmap_info.file = NULL; + struct file *f = mddev->bitmap_info.file; + if (f) { + spin_lock(&mddev->lock); + mddev->bitmap_info.file = NULL; + spin_unlock(&mddev->lock); + fput(f); + } } return err; @@ -6315,6 +6320,11 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode, case SET_DISK_FAULTY: err = set_disk_faulty(mddev, new_decode_dev(arg)); goto out; + + case GET_BITMAP_FILE: + err = get_bitmap_file(mddev, argp); + goto out; + } if (cmd == ADD_NEW_DISK) @@ -6406,10 +6416,6 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode, * Commands even a read-only array can execute: */ switch (cmd) { - case GET_BITMAP_FILE: - err = get_bitmap_file(mddev, argp); - goto unlock; - case RESTART_ARRAY_RW: err = restart_array(mddev); goto unlock; diff --git a/drivers/md/md.h b/drivers/md/md.h index 8770308a8052..b4fbd6a63fcf 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -393,6 +393,7 @@ struct mddev { * in_sync - and related safemode and MD_CHANGE changes * pers (also protected by reconfig_mutex and pending IO). * clearing ->bitmap + * clearing ->bitmap_info.file */ spinlock_t lock; wait_queue_head_t sb_wait; /* for waiting on superblock updates */ -- 2.39.2