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Btrfs: mount ro and remount support
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This patch adds mount ro and remount support. The main
changes in patch are: adding btrfs_remount and related
helper function; splitting the transaction related code
out of close_ctree into btrfs_commit_super; updating
allocator to properly handle read only block group.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
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@chrismason-xx
Yan Zheng authored and chrismason-xx committed Nov 12, 2008
1 parent f3465ca commit c146afa
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Showing 7 changed files with 163 additions and 58 deletions.
1 change: 1 addition & 0 deletions fs/btrfs/ctree.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -541,6 +541,7 @@ struct btrfs_space_info {
u64 bytes_used;
u64 bytes_pinned;
u64 bytes_reserved;
u64 bytes_readonly;
int full;
int force_alloc;
struct list_head list;
Expand Down
83 changes: 63 additions & 20 deletions fs/btrfs/disk-io.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1075,10 +1075,12 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
kfree(root);
return ERR_PTR(ret);
}
ret = btrfs_find_dead_roots(fs_info->tree_root,
root->root_key.objectid, root);
BUG_ON(ret);

if (!(fs_info->sb->s_flags & MS_RDONLY)) {
ret = btrfs_find_dead_roots(fs_info->tree_root,
root->root_key.objectid, root);
BUG_ON(ret);
btrfs_orphan_cleanup(root);
}
return root;
}

Expand Down Expand Up @@ -1700,7 +1702,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,

btrfs_read_block_groups(extent_root);

fs_info->generation = btrfs_super_generation(disk_super) + 1;
fs_info->generation = generation + 1;
fs_info->last_trans_committed = generation;
fs_info->data_alloc_profile = (u64)-1;
fs_info->metadata_alloc_profile = (u64)-1;
fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
Expand All @@ -1715,6 +1718,9 @@ struct btrfs_root *open_ctree(struct super_block *sb,
if (!fs_info->transaction_kthread)
goto fail_cleaner;

if (sb->s_flags & MS_RDONLY)
return tree_root;

if (btrfs_super_log_root(disk_super) != 0) {
u32 blocksize;
u64 bytenr = btrfs_super_log_root(disk_super);
Expand All @@ -1735,7 +1741,6 @@ struct btrfs_root *open_ctree(struct super_block *sb,
ret = btrfs_recover_log_trees(log_tree_root);
BUG_ON(ret);
}
fs_info->last_trans_committed = btrfs_super_generation(disk_super);

ret = btrfs_cleanup_reloc_trees(tree_root);
BUG_ON(ret);
Expand Down Expand Up @@ -1955,28 +1960,69 @@ static int del_fs_roots(struct btrfs_fs_info *fs_info)
return 0;
}

int close_ctree(struct btrfs_root *root)
int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
{
u64 root_objectid = 0;
struct btrfs_root *gang[8];
int i;
int ret;
struct btrfs_trans_handle *trans;
struct btrfs_fs_info *fs_info = root->fs_info;

fs_info->closing = 1;
smp_mb();
while (1) {
ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
(void **)gang, root_objectid,
ARRAY_SIZE(gang));
if (!ret)
break;
for (i = 0; i < ret; i++) {
root_objectid = gang[i]->root_key.objectid;
ret = btrfs_find_dead_roots(fs_info->tree_root,
root_objectid, gang[i]);
BUG_ON(ret);
btrfs_orphan_cleanup(gang[i]);
}
root_objectid++;
}
return 0;
}

kthread_stop(root->fs_info->transaction_kthread);
kthread_stop(root->fs_info->cleaner_kthread);
int btrfs_commit_super(struct btrfs_root *root)
{
struct btrfs_trans_handle *trans;
int ret;

mutex_lock(&root->fs_info->cleaner_mutex);
btrfs_clean_old_snapshots(root);
mutex_unlock(&root->fs_info->cleaner_mutex);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_commit_transaction(trans, root);
/* run commit again to drop the original snapshot */
BUG_ON(ret);
/* run commit again to drop the original snapshot */
trans = btrfs_start_transaction(root, 1);
btrfs_commit_transaction(trans, root);
ret = btrfs_write_and_wait_transaction(NULL, root);
BUG_ON(ret);

write_ctree_super(NULL, root);
ret = write_ctree_super(NULL, root);
return ret;
}

int close_ctree(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;

fs_info->closing = 1;
smp_mb();

kthread_stop(root->fs_info->transaction_kthread);
kthread_stop(root->fs_info->cleaner_kthread);

if (!(fs_info->sb->s_flags & MS_RDONLY)) {
ret = btrfs_commit_super(root);
if (ret) {
printk("btrfs: commit super returns %d\n", ret);
}
}

if (fs_info->delalloc_bytes) {
printk("btrfs: at unmount delalloc count %Lu\n",
Expand All @@ -2000,12 +2046,10 @@ int close_ctree(struct btrfs_root *root)
free_extent_buffer(root->fs_info->dev_root->node);

btrfs_free_block_groups(root->fs_info);
fs_info->closing = 2;
del_fs_roots(fs_info);

filemap_write_and_wait(fs_info->btree_inode->i_mapping);
del_fs_roots(fs_info);

truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
iput(fs_info->btree_inode);

btrfs_stop_workers(&fs_info->fixup_workers);
btrfs_stop_workers(&fs_info->delalloc_workers);
Expand All @@ -2014,7 +2058,6 @@ int close_ctree(struct btrfs_root *root)
btrfs_stop_workers(&fs_info->endio_write_workers);
btrfs_stop_workers(&fs_info->submit_workers);

iput(fs_info->btree_inode);
#if 0
while(!list_empty(&fs_info->hashers)) {
struct btrfs_hasher *hasher;
Expand Down
2 changes: 2 additions & 0 deletions fs/btrfs/disk-io.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -38,6 +38,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
int close_ctree(struct btrfs_root *root);
int write_ctree_super(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_commit_super(struct btrfs_root *root);
struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
u64 bytenr, u32 blocksize);
struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
Expand All @@ -49,6 +50,7 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
struct btrfs_key *location);
struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
struct btrfs_key *location);
int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
int btrfs_insert_dev_radix(struct btrfs_root *root,
struct block_device *bdev,
u64 device_id,
Expand Down
61 changes: 35 additions & 26 deletions fs/btrfs/extent-tree.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1794,7 +1794,7 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
*space_info = found;
return 0;
}
found = kmalloc(sizeof(*found), GFP_NOFS);
found = kzalloc(sizeof(*found), GFP_NOFS);
if (!found)
return -ENOMEM;

Expand All @@ -1807,6 +1807,7 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
found->bytes_used = bytes_used;
found->bytes_pinned = 0;
found->bytes_reserved = 0;
found->bytes_readonly = 0;
found->full = 0;
found->force_alloc = 0;
*space_info = found;
Expand All @@ -1829,6 +1830,19 @@ static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
}
}

static void set_block_group_readonly(struct btrfs_block_group_cache *cache)
{
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
if (!cache->ro) {
cache->space_info->bytes_readonly += cache->key.offset -
btrfs_block_group_used(&cache->item);
cache->ro = 1;
}
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
}

static u64 reduce_alloc_profile(struct btrfs_root *root, u64 flags)
{
u64 num_devices = root->fs_info->fs_devices->num_devices;
Expand Down Expand Up @@ -1865,7 +1879,9 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans,
u64 thresh;
u64 start;
u64 num_bytes;
int ret = 0, waited = 0;
int ret = 0;

mutex_lock(&extent_root->fs_info->chunk_mutex);

flags = reduce_alloc_profile(extent_root, flags);

Expand All @@ -1887,46 +1903,28 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans,
goto out;
}

thresh = div_factor(space_info->total_bytes, 6);
thresh = space_info->total_bytes - space_info->bytes_readonly;
thresh = div_factor(thresh, 6);
if (!force &&
(space_info->bytes_used + space_info->bytes_pinned +
space_info->bytes_reserved + alloc_bytes) < thresh) {
spin_unlock(&space_info->lock);
goto out;
}

spin_unlock(&space_info->lock);

ret = mutex_trylock(&extent_root->fs_info->chunk_mutex);
if (!ret && !force) {
goto out;
} else if (!ret) {
mutex_lock(&extent_root->fs_info->chunk_mutex);
waited = 1;
}

if (waited) {
spin_lock(&space_info->lock);
if (space_info->full) {
spin_unlock(&space_info->lock);
goto out_unlock;
}
spin_unlock(&space_info->lock);
}

ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
if (ret) {
printk("space info full %Lu\n", flags);
space_info->full = 1;
goto out_unlock;
goto out;
}

ret = btrfs_make_block_group(trans, extent_root, 0, flags,
BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
BUG_ON(ret);
out_unlock:
mutex_unlock(&extent_root->fs_info->chunk_mutex);
out:
mutex_unlock(&extent_root->fs_info->chunk_mutex);
return ret;
}

Expand Down Expand Up @@ -1956,12 +1954,18 @@ static int update_block_group(struct btrfs_trans_handle *trans,
if (alloc) {
old_val += num_bytes;
cache->space_info->bytes_used += num_bytes;
if (cache->ro) {
cache->space_info->bytes_readonly -= num_bytes;
WARN_ON(1);
}
btrfs_set_block_group_used(&cache->item, old_val);
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
} else {
old_val -= num_bytes;
cache->space_info->bytes_used -= num_bytes;
if (cache->ro)
cache->space_info->bytes_readonly += num_bytes;
btrfs_set_block_group_used(&cache->item, old_val);
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
Expand Down Expand Up @@ -5560,8 +5564,7 @@ int btrfs_relocate_block_group(struct btrfs_root *root, u64 group_start)
BUG_ON(IS_ERR(reloc_inode));

__alloc_chunk_for_shrink(root, block_group, 1);
block_group->ro = 1;
block_group->space_info->total_bytes -= block_group->key.offset;
set_block_group_readonly(block_group);

btrfs_start_delalloc_inodes(info->tree_root);
btrfs_wait_ordered_extents(info->tree_root, 0);
Expand Down Expand Up @@ -5868,6 +5871,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,

block_group = btrfs_lookup_block_group(root->fs_info, group_start);
BUG_ON(!block_group);
BUG_ON(!block_group->ro);

memcpy(&key, &block_group->key, sizeof(key));

Expand All @@ -5881,6 +5885,11 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
list_del(&block_group->list);
up_write(&block_group->space_info->groups_sem);

spin_lock(&block_group->space_info->lock);
block_group->space_info->total_bytes -= block_group->key.offset;
block_group->space_info->bytes_readonly -= block_group->key.offset;
spin_unlock(&block_group->space_info->lock);

/*
memset(shrink_block_group, 0, sizeof(*shrink_block_group));
kfree(shrink_block_group);
Expand Down
15 changes: 5 additions & 10 deletions fs/btrfs/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1808,10 +1808,6 @@ void btrfs_orphan_cleanup(struct btrfs_root *root)
struct inode *inode;
int ret = 0, nr_unlink = 0, nr_truncate = 0;

/* don't do orphan cleanup if the fs is readonly. */
if (root->fs_info->sb->s_flags & MS_RDONLY)
return;

path = btrfs_alloc_path();
if (!path)
return;
Expand Down Expand Up @@ -3050,7 +3046,7 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
struct btrfs_root *root = bi->root;
struct btrfs_root *sub_root = root;
struct btrfs_key location;
int ret, new, do_orphan = 0;
int ret, new;

if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
Expand All @@ -3076,13 +3072,9 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
if (new && root != sub_root) {
igrab(inode);
sub_root->inode = inode;
do_orphan = 1;
}
}

if (unlikely(do_orphan))
btrfs_orphan_cleanup(sub_root);

return d_splice_alias(inode, dentry);
}

Expand Down Expand Up @@ -3237,7 +3229,7 @@ int btrfs_write_inode(struct inode *inode, int wait)
struct btrfs_trans_handle *trans;
int ret = 0;

if (root->fs_info->closing > 1)
if (root->fs_info->btree_inode == inode)
return 0;

if (wait) {
Expand Down Expand Up @@ -4625,6 +4617,9 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root)
struct inode *inode;
unsigned long flags;

if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;

spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
while(!list_empty(head)) {
binode = list_entry(head->next, struct btrfs_inode,
Expand Down
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