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/hfs/super.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'fs/hfs') diff --git a/fs/hfs/super.c b/fs/hfs/super.c index 34235d4bf08b..3069416fa8ef 100644 --- a/fs/hfs/super.c +++ b/fs/hfs/super.c @@ -382,9 +382,13 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent) struct inode *root_inode; int res; + lock_kernel(); + sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL); - if (!sbi) + if (!sbi) { + unlock_kernel(); return -ENOMEM; + } sb->s_fs_info = sbi; INIT_HLIST_HEAD(&sbi->rsrc_inodes); @@ -435,6 +439,7 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent) sb->s_root->d_op = &hfs_dentry_operations; /* everything's okay */ + unlock_kernel(); return 0; bail_iput: @@ -443,6 +448,7 @@ bail_no_root: printk(KERN_ERR "hfs: get root inode failed.\n"); bail: hfs_mdb_put(sb); + unlock_kernel(); return res; } -- cgit v1.2.3-59-g8ed1b From 8526fb37c907f8f4eb9965367af6aeec76aedbce Mon Sep 17 00:00:00 2001 From: Jan Blunck Date: Wed, 24 Feb 2010 13:25:30 +0100 Subject: BKL: Remove BKL from HFS The BKL is only used in put_super and fill_super that are both protected by the superblocks s_umount rw_semaphore. Therefore it is safe to remove the BKL entirely. Signed-off-by: Jan Blunck Signed-off-by: Arnd Bergmann --- fs/hfs/super.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) (limited to 'fs/hfs') diff --git a/fs/hfs/super.c b/fs/hfs/super.c index 3069416fa8ef..33254160f650 100644 --- a/fs/hfs/super.c +++ b/fs/hfs/super.c @@ -20,7 +20,6 @@ #include #include #include -#include #include #include "hfs_fs.h" @@ -79,15 +78,11 @@ static int hfs_sync_fs(struct super_block *sb, int wait) */ static void hfs_put_super(struct super_block *sb) { - lock_kernel(); - if (sb->s_dirt) hfs_write_super(sb); hfs_mdb_close(sb); /* release the MDB's resources */ hfs_mdb_put(sb); - - unlock_kernel(); } /* @@ -382,13 +377,10 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent) struct inode *root_inode; int res; - lock_kernel(); - sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL); - if (!sbi) { - unlock_kernel(); + if (!sbi) return -ENOMEM; - } + sb->s_fs_info = sbi; INIT_HLIST_HEAD(&sbi->rsrc_inodes); @@ -439,7 +431,6 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent) sb->s_root->d_op = &hfs_dentry_operations; /* everything's okay */ - unlock_kernel(); return 0; bail_iput: @@ -448,7 +439,6 @@ bail_no_root: printk(KERN_ERR "hfs: get root inode failed.\n"); bail: hfs_mdb_put(sb); - unlock_kernel(); return res; } -- cgit v1.2.3-59-g8ed1b