From db71922217a214e5c9268448e537b54fc1f301ea Mon Sep 17 00:00:00 2001 From: Jan Blunck Date: Sun, 15 Aug 2010 22:51:10 +0200 Subject: BKL: Explicitly add BKL around get_sb/fill_super This patch is a preparation necessary to remove the BKL from do_new_mount(). It explicitly adds calls to lock_kernel()/unlock_kernel() around get_sb/fill_super operations for filesystems that still uses the BKL. I've read through all the code formerly covered by the BKL inside do_kern_mount() and have satisfied myself that it doesn't need the BKL any more. do_kern_mount() is already called without the BKL when mounting the rootfs and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called from various places without BKL: simple_pin_fs(), nfs_do_clone_mount() through nfs_follow_mountpoint(), afs_mntpt_do_automount() through afs_mntpt_follow_link(). Both later functions are actually the filesystems follow_link inode operation. vfs_kern_mount() is calling the specified get_sb function and lets the filesystem do its job by calling the given fill_super function. Therefore I think it is safe to push down the BKL from the VFS to the low-level filesystems get_sb/fill_super operation. [arnd: do not add the BKL to those file systems that already don't use it elsewhere] Signed-off-by: Jan Blunck Signed-off-by: Arnd Bergmann Cc: Matthew Wilcox Cc: Christoph Hellwig --- fs/jffs2/super.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'fs/jffs2') diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c index 662bba099501..58dd9cf06206 100644 --- a/fs/jffs2/super.c +++ b/fs/jffs2/super.c @@ -146,14 +146,19 @@ static const struct super_operations jffs2_super_operations = static int jffs2_fill_super(struct super_block *sb, void *data, int silent) { struct jffs2_sb_info *c; + int ret; + + lock_kernel(); D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():" " New superblock for device %d (\"%s\")\n", sb->s_mtd->index, sb->s_mtd->name)); c = kzalloc(sizeof(*c), GFP_KERNEL); - if (!c) + if (!c) { + unlock_kernel(); return -ENOMEM; + } c->mtd = sb->s_mtd; c->os_priv = sb; @@ -175,7 +180,9 @@ static int jffs2_fill_super(struct super_block *sb, void *data, int silent) #ifdef CONFIG_JFFS2_FS_POSIX_ACL sb->s_flags |= MS_POSIXACL; #endif - return jffs2_do_fill_super(sb, data, silent); + ret = jffs2_do_fill_super(sb, data, silent); + unlock_kernel(); + return ret; } static int jffs2_get_sb(struct file_system_type *fs_type, -- cgit v1.2.3 From 1a028dd2dd589c3924d9711a1b073a13c820b6b5 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 16 Sep 2010 16:11:09 +0200 Subject: BKL: Remove BKL from jffs2 The BKL is only used in put_super, fill_super and remount_fs that are all three protected by the superblocks s_umount rw_semaphore. Therefore it is safe to remove the BKL entirely. Signed-off-by: Arnd Bergmann Cc: David Woodhouse --- fs/jffs2/fs.c | 4 ---- fs/jffs2/super.c | 12 +----------- 2 files changed, 1 insertion(+), 15 deletions(-) (limited to 'fs/jffs2') diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c index 6b2964a19850..d9beb06e6fca 100644 --- a/fs/jffs2/fs.c +++ b/fs/jffs2/fs.c @@ -21,7 +21,6 @@ #include #include #include -#include #include "nodelist.h" static int jffs2_flash_setup(struct jffs2_sb_info *c); @@ -391,7 +390,6 @@ int jffs2_remount_fs (struct super_block *sb, int *flags, char *data) This also catches the case where it was stopped and this is just a remount to restart it. Flush the writebuffer, if neccecary, else we loose it */ - lock_kernel(); if (!(sb->s_flags & MS_RDONLY)) { jffs2_stop_garbage_collect_thread(c); mutex_lock(&c->alloc_sem); @@ -403,8 +401,6 @@ int jffs2_remount_fs (struct super_block *sb, int *flags, char *data) jffs2_start_garbage_collect_thread(c); *flags |= MS_NOATIME; - - unlock_kernel(); return 0; } diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c index 58dd9cf06206..d1ae5dfc22b9 100644 --- a/fs/jffs2/super.c +++ b/fs/jffs2/super.c @@ -12,7 +12,6 @@ #include #include #include -#include #include #include #include @@ -148,17 +147,13 @@ static int jffs2_fill_super(struct super_block *sb, void *data, int silent) struct jffs2_sb_info *c; int ret; - lock_kernel(); - D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():" " New superblock for device %d (\"%s\")\n", sb->s_mtd->index, sb->s_mtd->name)); c = kzalloc(sizeof(*c), GFP_KERNEL); - if (!c) { - unlock_kernel(); + if (!c) return -ENOMEM; - } c->mtd = sb->s_mtd; c->os_priv = sb; @@ -181,7 +176,6 @@ static int jffs2_fill_super(struct super_block *sb, void *data, int silent) sb->s_flags |= MS_POSIXACL; #endif ret = jffs2_do_fill_super(sb, data, silent); - unlock_kernel(); return ret; } @@ -199,8 +193,6 @@ static void jffs2_put_super (struct super_block *sb) D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n")); - lock_kernel(); - if (sb->s_dirt) jffs2_write_super(sb); @@ -222,8 +214,6 @@ static void jffs2_put_super (struct super_block *sb) if (c->mtd->sync) c->mtd->sync(c->mtd); - unlock_kernel(); - D1(printk(KERN_DEBUG "jffs2_put_super returning\n")); } -- cgit v1.2.3