Btrfs: Replace the big fs_mutex with a collection of other locks

[linux-2.6-block.git] / fs / btrfs / ioctl.c

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index da8de6cfdb5a3eb9ae7451f221e3f134e18a878e..6002eb64daf938e7fcf1a84959cf485526fef69e 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -43,6 +43,7 @@
 #include "ioctl.h"
 #include "print-tree.h"
 #include "volumes.h"
+#include "locking.h"
 
 
 
@@ -62,7 +63,6 @@ static noinline int create_subvol(struct btrfs_root *root, char *name,
        u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
        unsigned long nr = 1;
 
-       mutex_lock(&root->fs_info->fs_mutex);
        ret = btrfs_check_free_space(root, 1, 0);
        if (ret)
                goto fail_commit;
@@ -75,9 +75,9 @@ static noinline int create_subvol(struct btrfs_root *root, char *name,
        if (ret)
                goto fail;
 
-       leaf = __btrfs_alloc_free_block(trans, root, root->leafsize,
-                                       objectid, trans->transid, 0, 0,
-                                       0, 0);
+       leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
+                                     objectid, trans->transid, 0, 0,
+                                     0, 0);
        if (IS_ERR(leaf))
                return PTR_ERR(leaf);
 
@@ -108,6 +108,7 @@ static noinline int create_subvol(struct btrfs_root *root, char *name,
        memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
        root_item.drop_level = 0;
 
+       btrfs_tree_unlock(leaf);
        free_extent_buffer(leaf);
        leaf = NULL;
 
@@ -162,7 +163,6 @@ fail:
        if (err && !ret)
                ret = err;
 fail_commit:
-       mutex_unlock(&root->fs_info->fs_mutex);
        btrfs_btree_balance_dirty(root, nr);
        btrfs_throttle(root);
        return ret;
@@ -179,7 +179,6 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
        if (!root->ref_cows)
                return -EINVAL;
 
-       mutex_lock(&root->fs_info->fs_mutex);
        ret = btrfs_check_free_space(root, 1, 0);
        if (ret)
                goto fail_unlock;
@@ -206,7 +205,6 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
        err = btrfs_commit_transaction(trans, root);
 
 fail_unlock:
-       mutex_unlock(&root->fs_info->fs_mutex);
        btrfs_btree_balance_dirty(root, nr);
        btrfs_throttle(root);
        return ret;
@@ -226,9 +224,7 @@ int btrfs_defrag_file(struct file *file)
        unsigned long i;
        int ret;
 
-       mutex_lock(&root->fs_info->fs_mutex);
        ret = btrfs_check_free_space(root, inode->i_size, 0);
-       mutex_unlock(&root->fs_info->fs_mutex);
        if (ret)
                return -ENOSPC;
 
@@ -313,7 +309,8 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
                goto out;
        }
 
-       mutex_lock(&root->fs_info->fs_mutex);
+       mutex_lock(&root->fs_info->alloc_mutex);
+       mutex_lock(&root->fs_info->chunk_mutex);
        sizestr = vol_args->name;
        devstr = strchr(sizestr, ':');
        if (devstr) {
@@ -383,7 +380,8 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
        }
 
 out_unlock:
-       mutex_unlock(&root->fs_info->fs_mutex);
+       mutex_lock(&root->fs_info->alloc_mutex);
+       mutex_lock(&root->fs_info->chunk_mutex);
 out:
        kfree(vol_args);
        return ret;
@@ -426,11 +424,9 @@ static noinline int btrfs_ioctl_snap_create(struct btrfs_root *root,
        }
 
        root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
-       mutex_lock(&root->fs_info->fs_mutex);
        di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
                            path, root_dirid,
                            vol_args->name, namelen, 0);
-       mutex_unlock(&root->fs_info->fs_mutex);
        btrfs_free_path(path);
 
        if (di && !IS_ERR(di)) {
@@ -443,10 +439,12 @@ static noinline int btrfs_ioctl_snap_create(struct btrfs_root *root,
                goto out;
        }
 
+       mutex_lock(&root->fs_info->drop_mutex);
        if (root == root->fs_info->tree_root)
                ret = create_subvol(root, vol_args->name, namelen);
        else
                ret = create_snapshot(root, vol_args->name, namelen);
+       mutex_unlock(&root->fs_info->drop_mutex);
 out:
        kfree(vol_args);
        return ret;
@@ -459,10 +457,8 @@ static int btrfs_ioctl_defrag(struct file *file)
 
        switch (inode->i_mode & S_IFMT) {
        case S_IFDIR:
-               mutex_lock(&root->fs_info->fs_mutex);
                btrfs_defrag_root(root, 0);
                btrfs_defrag_root(root->fs_info->extent_root, 0);
-               mutex_unlock(&root->fs_info->fs_mutex);
                break;
        case S_IFREG:
                btrfs_defrag_file(file);
@@ -586,7 +582,6 @@ long btrfs_ioctl_clone(struct file *file, unsigned long src_fd)
                unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
        }
 
-       mutex_lock(&root->fs_info->fs_mutex);
        trans = btrfs_start_transaction(root, 0);
        path = btrfs_alloc_path();
        if (!path) {
@@ -683,7 +678,6 @@ out:
        unlock_extent(&BTRFS_I(src)->io_tree, 0, (u64)-1, GFP_NOFS);
 
        btrfs_end_transaction(trans, root);
-       mutex_unlock(&root->fs_info->fs_mutex);
 
 out_unlock:
        mutex_unlock(&src->i_mutex);
@@ -706,7 +700,9 @@ long btrfs_ioctl_trans_start(struct file *file)
        struct btrfs_trans_handle *trans;
        int ret = 0;
 
-       mutex_lock(&root->fs_info->fs_mutex);
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
        if (file->private_data) {
                ret = -EINPROGRESS;
                goto out;
@@ -718,7 +714,6 @@ long btrfs_ioctl_trans_start(struct file *file)
                ret = -ENOMEM;
        /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/
 out:
-       mutex_unlock(&root->fs_info->fs_mutex);
        return ret;
 }
 
@@ -735,7 +730,6 @@ long btrfs_ioctl_trans_end(struct file *file)
        struct btrfs_trans_handle *trans;
        int ret = 0;
 
-       mutex_lock(&root->fs_info->fs_mutex);
        trans = file->private_data;
        if (!trans) {
                ret = -EINVAL;
@@ -744,7 +738,6 @@ long btrfs_ioctl_trans_end(struct file *file)
        btrfs_end_transaction(trans, root);
        file->private_data = 0;
 out:
-       mutex_unlock(&root->fs_info->fs_mutex);
        return ret;
 }