| Message ID | 1438235311-23788-5-git-send-email-yangds.fnst@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu 30-07-15 13:48:00, Dongsheng Yang wrote: > There is a lot of duplicated code in get_super and user_get_super. > This commit introduc a __get_super as a common function to reduce > the duplication of it. > > Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> The patch looks good to me. You can add: Reviewed-by: Jan Kara <jack@suse.com> Honza > --- > fs/super.c | 64 ++++++++++++++++++++++++++++++-------------------------------- > 1 file changed, 31 insertions(+), 33 deletions(-) > > diff --git a/fs/super.c b/fs/super.c > index fadb677..46fd1f1 100644 > --- a/fs/super.c > +++ b/fs/super.c > @@ -559,19 +559,20 @@ void iterate_supers_type(struct file_system_type *type, > } > EXPORT_SYMBOL(iterate_supers_type); > > -/** > - * get_super - get the superblock of a device > - * @bdev: device to get the superblock for > - * > - * Scans the superblock list and finds the superblock of the file system > - * mounted on the device given. %NULL is returned if no match is found. > +/* > + * __get_super - helper function for the other functions in get_super class > + * @compare: function pointer to compare sb in list and key > + * @key: key of the sb you want > + * > + * Scans the superblock list and finds the superblock you want. %NULL is > + * returned if no match is found. > */ > - > -struct super_block *get_super(struct block_device *bdev) > +static struct super_block *__get_super( > + int (*compare)(struct super_block *, void *), void *key) > { > struct super_block *sb; > > - if (!bdev) > + if (!key) > return NULL; > > spin_lock(&sb_lock); > @@ -579,7 +580,7 @@ rescan: > list_for_each_entry(sb, &super_blocks, s_list) { > if (hlist_unhashed(&sb->s_instances)) > continue; > - if (sb->s_bdev == bdev) { > + if (compare(sb, key)) { > sb->s_count++; > spin_unlock(&sb_lock); > down_read(&sb->s_umount); > @@ -596,6 +597,20 @@ rescan: > spin_unlock(&sb_lock); > return NULL; > } > + > +static int bdev_compare(struct super_block *sb, void *key) > +{ > + return (sb->s_bdev == (struct block_device *)key); > +} > + > +/** > + * get_super - get the superblock of a device > + * @bdev: device to get the superblock for > + */ > +struct super_block *get_super(struct block_device *bdev) > +{ > + return __get_super(bdev_compare, bdev); > +} > EXPORT_SYMBOL(get_super); > > /** > @@ -651,32 +666,15 @@ restart: > spin_unlock(&sb_lock); > return NULL; > } > + > +static int user_compare(struct super_block *sb, void *key) > +{ > + return (sb->s_dev == *(dev_t *)key); > +} > > struct super_block *user_get_super(dev_t dev) > { > - struct super_block *sb; > - > - spin_lock(&sb_lock); > -rescan: > - list_for_each_entry(sb, &super_blocks, s_list) { > - if (hlist_unhashed(&sb->s_instances)) > - continue; > - if (sb->s_dev == dev) { > - sb->s_count++; > - spin_unlock(&sb_lock); > - down_read(&sb->s_umount); > - /* still alive? */ > - if (sb->s_root && (sb->s_flags & MS_BORN)) > - return sb; > - up_read(&sb->s_umount); > - /* nope, got unmounted */ > - spin_lock(&sb_lock); > - __put_super(sb); > - goto rescan; > - } > - } > - spin_unlock(&sb_lock); > - return NULL; > + return __get_super(user_compare, &dev); > } > > /** > -- > 1.8.4.2 >
diff --git a/fs/super.c b/fs/super.c index fadb677..46fd1f1 100644 --- a/fs/super.c +++ b/fs/super.c @@ -559,19 +559,20 @@ void iterate_supers_type(struct file_system_type *type, } EXPORT_SYMBOL(iterate_supers_type); -/** - * get_super - get the superblock of a device - * @bdev: device to get the superblock for - * - * Scans the superblock list and finds the superblock of the file system - * mounted on the device given. %NULL is returned if no match is found. +/* + * __get_super - helper function for the other functions in get_super class + * @compare: function pointer to compare sb in list and key + * @key: key of the sb you want + * + * Scans the superblock list and finds the superblock you want. %NULL is + * returned if no match is found. */ - -struct super_block *get_super(struct block_device *bdev) +static struct super_block *__get_super( + int (*compare)(struct super_block *, void *), void *key) { struct super_block *sb; - if (!bdev) + if (!key) return NULL; spin_lock(&sb_lock); @@ -579,7 +580,7 @@ rescan: list_for_each_entry(sb, &super_blocks, s_list) { if (hlist_unhashed(&sb->s_instances)) continue; - if (sb->s_bdev == bdev) { + if (compare(sb, key)) { sb->s_count++; spin_unlock(&sb_lock); down_read(&sb->s_umount); @@ -596,6 +597,20 @@ rescan: spin_unlock(&sb_lock); return NULL; } + +static int bdev_compare(struct super_block *sb, void *key) +{ + return (sb->s_bdev == (struct block_device *)key); +} + +/** + * get_super - get the superblock of a device + * @bdev: device to get the superblock for + */ +struct super_block *get_super(struct block_device *bdev) +{ + return __get_super(bdev_compare, bdev); +} EXPORT_SYMBOL(get_super); /** @@ -651,32 +666,15 @@ restart: spin_unlock(&sb_lock); return NULL; } + +static int user_compare(struct super_block *sb, void *key) +{ + return (sb->s_dev == *(dev_t *)key); +} struct super_block *user_get_super(dev_t dev) { - struct super_block *sb; - - spin_lock(&sb_lock); -rescan: - list_for_each_entry(sb, &super_blocks, s_list) { - if (hlist_unhashed(&sb->s_instances)) - continue; - if (sb->s_dev == dev) { - sb->s_count++; - spin_unlock(&sb_lock); - down_read(&sb->s_umount); - /* still alive? */ - if (sb->s_root && (sb->s_flags & MS_BORN)) - return sb; - up_read(&sb->s_umount); - /* nope, got unmounted */ - spin_lock(&sb_lock); - __put_super(sb); - goto rescan; - } - } - spin_unlock(&sb_lock); - return NULL; + return __get_super(user_compare, &dev); } /**
There is a lot of duplicated code in get_super and user_get_super. This commit introduc a __get_super as a common function to reduce the duplication of it. Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> --- fs/super.c | 64 ++++++++++++++++++++++++++++++-------------------------------- 1 file changed, 31 insertions(+), 33 deletions(-)