From 788257d6101d986ac8f2741aaa35974af47f574c Mon Sep 17 00:00:00 2001 From: Arnd Bergmann <arnd@arndb.de> Date: Mon, 24 Jan 2011 10:14:12 +0100 Subject: ufs: remove the BKL This introduces a new per-superblock mutex in UFS to replace the big kernel lock. I have been careful to avoid nested calls to lock_ufs and to get the lock order right with respect to other mutexes, in particular lock_super. I did not make any attempt to prove that the big kernel lock is not needed in a particular place in the code, which is very possible. The mutex has a significant performance impact, so it is only used on SMP or PREEMPT configurations. As Nick Piggin noticed, any allocation inside of the lock may end up deadlocking when we get to ufs_getfrag_block in the reclaim task, so we now use GFP_NOFS. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Nick Bowler <nbowler@elliptictech.com> Cc: Evgeniy Dushistov <dushistov@mail.ru> Cc: Nick Piggin <npiggin@gmail.com> --- fs/ufs/namei.c | 35 +++++++++++++++++------------------ 1 file changed, 17 insertions(+), 18 deletions(-) (limited to 'fs/ufs/namei.c') diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c index 12f39b9e4437..205030a707fe 100644 --- a/fs/ufs/namei.c +++ b/fs/ufs/namei.c @@ -29,7 +29,6 @@ #include <linux/time.h> #include <linux/fs.h> -#include <linux/smp_lock.h> #include "ufs_fs.h" #include "ufs.h" @@ -55,16 +54,16 @@ static struct dentry *ufs_lookup(struct inode * dir, struct dentry *dentry, stru if (dentry->d_name.len > UFS_MAXNAMLEN) return ERR_PTR(-ENAMETOOLONG); - lock_kernel(); + lock_ufs(dir->i_sb); ino = ufs_inode_by_name(dir, &dentry->d_name); if (ino) { inode = ufs_iget(dir->i_sb, ino); if (IS_ERR(inode)) { - unlock_kernel(); + unlock_ufs(dir->i_sb); return ERR_CAST(inode); } } - unlock_kernel(); + unlock_ufs(dir->i_sb); d_add(dentry, inode); return NULL; } @@ -93,9 +92,9 @@ static int ufs_create (struct inode * dir, struct dentry * dentry, int mode, inode->i_fop = &ufs_file_operations; inode->i_mapping->a_ops = &ufs_aops; mark_inode_dirty(inode); - lock_kernel(); + lock_ufs(dir->i_sb); err = ufs_add_nondir(dentry, inode); - unlock_kernel(); + unlock_ufs(dir->i_sb); } UFSD("END: err=%d\n", err); return err; @@ -115,9 +114,9 @@ static int ufs_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t init_special_inode(inode, mode, rdev); ufs_set_inode_dev(inode->i_sb, UFS_I(inode), rdev); mark_inode_dirty(inode); - lock_kernel(); + lock_ufs(dir->i_sb); err = ufs_add_nondir(dentry, inode); - unlock_kernel(); + unlock_ufs(dir->i_sb); } return err; } @@ -133,7 +132,7 @@ static int ufs_symlink (struct inode * dir, struct dentry * dentry, if (l > sb->s_blocksize) goto out_notlocked; - lock_kernel(); + lock_ufs(dir->i_sb); inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO); err = PTR_ERR(inode); if (IS_ERR(inode)) @@ -156,7 +155,7 @@ static int ufs_symlink (struct inode * dir, struct dentry * dentry, err = ufs_add_nondir(dentry, inode); out: - unlock_kernel(); + unlock_ufs(dir->i_sb); out_notlocked: return err; @@ -172,9 +171,9 @@ static int ufs_link (struct dentry * old_dentry, struct inode * dir, struct inode *inode = old_dentry->d_inode; int error; - lock_kernel(); + lock_ufs(dir->i_sb); if (inode->i_nlink >= UFS_LINK_MAX) { - unlock_kernel(); + unlock_ufs(dir->i_sb); return -EMLINK; } @@ -183,7 +182,7 @@ static int ufs_link (struct dentry * old_dentry, struct inode * dir, ihold(inode); error = ufs_add_nondir(dentry, inode); - unlock_kernel(); + unlock_ufs(dir->i_sb); return error; } @@ -195,7 +194,7 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, int mode) if (dir->i_nlink >= UFS_LINK_MAX) goto out; - lock_kernel(); + lock_ufs(dir->i_sb); inode_inc_link_count(dir); inode = ufs_new_inode(dir, S_IFDIR|mode); @@ -216,7 +215,7 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, int mode) err = ufs_add_link(dentry, inode); if (err) goto out_fail; - unlock_kernel(); + unlock_ufs(dir->i_sb); d_instantiate(dentry, inode); out: @@ -228,7 +227,7 @@ out_fail: iput (inode); out_dir: inode_dec_link_count(dir); - unlock_kernel(); + unlock_ufs(dir->i_sb); goto out; } @@ -259,7 +258,7 @@ static int ufs_rmdir (struct inode * dir, struct dentry *dentry) struct inode * inode = dentry->d_inode; int err= -ENOTEMPTY; - lock_kernel(); + lock_ufs(dir->i_sb); if (ufs_empty_dir (inode)) { err = ufs_unlink(dir, dentry); if (!err) { @@ -268,7 +267,7 @@ static int ufs_rmdir (struct inode * dir, struct dentry *dentry) inode_dec_link_count(dir); } } - unlock_kernel(); + unlock_ufs(dir->i_sb); return err; } -- cgit v1.2.3