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authorLinus Torvalds <torvalds@linux-foundation.org>2020-01-17 11:21:05 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-01-17 11:21:05 -0800
commiteffaf90137e3a9bb9702746f993f369a53c4185f (patch)
tree8fdf11b4e9bfbcf159b6f73928fa2782c04b433c /fs
parentab7541c3addd344939e76d0636da0048ce24f2db (diff)
parentb35cf1f0bf1f2b0b193093338414b9bd63b29015 (diff)
Merge tag 'for-5.5-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba: "A few more fixes that have been in the works during last twp weeks. All have a user visible effect and are stable material: - scrub: properly update progress after calling cancel ioctl, calling 'resume' would start from the beginning otherwise - fix subvolume reference removal, after moving out of the original path the reference is not recognized and will lead to transaction abort - fix reloc root lifetime checks, could lead to crashes when there's subvolume cleaning running in parallel - fix memory leak when quotas get disabled in the middle of extent accounting - fix transaction abort in case of balance being started on degraded mount on eg. RAID1" * tag 'for-5.5-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: check rw_devices, not num_devices for balance Btrfs: always copy scrub arguments back to user space btrfs: relocation: fix reloc_root lifespan and access btrfs: fix memory leak in qgroup accounting btrfs: do not delete mismatched root refs btrfs: fix invalid removal of root ref btrfs: rework arguments of btrfs_unlink_subvol
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/inode.c73
-rw-r--r--fs/btrfs/ioctl.c14
-rw-r--r--fs/btrfs/qgroup.c6
-rw-r--r--fs/btrfs/relocation.c51
-rw-r--r--fs/btrfs/root-tree.c10
-rw-r--r--fs/btrfs/volumes.c6
6 files changed, 114 insertions, 46 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5509c41a4f43..c70baafb2a39 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4238,18 +4238,30 @@ out:
}
static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
- struct inode *dir, u64 objectid,
- const char *name, int name_len)
+ struct inode *dir, struct dentry *dentry)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
+ struct btrfs_inode *inode = BTRFS_I(d_inode(dentry));
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key key;
+ const char *name = dentry->d_name.name;
+ int name_len = dentry->d_name.len;
u64 index;
int ret;
+ u64 objectid;
u64 dir_ino = btrfs_ino(BTRFS_I(dir));
+ if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) {
+ objectid = inode->root->root_key.objectid;
+ } else if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
+ objectid = inode->location.objectid;
+ } else {
+ WARN_ON(1);
+ return -EINVAL;
+ }
+
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
@@ -4271,13 +4283,16 @@ static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
}
btrfs_release_path(path);
- ret = btrfs_del_root_ref(trans, objectid, root->root_key.objectid,
- dir_ino, &index, name, name_len);
- if (ret < 0) {
- if (ret != -ENOENT) {
- btrfs_abort_transaction(trans, ret);
- goto out;
- }
+ /*
+ * This is a placeholder inode for a subvolume we didn't have a
+ * reference to at the time of the snapshot creation. In the meantime
+ * we could have renamed the real subvol link into our snapshot, so
+ * depending on btrfs_del_root_ref to return -ENOENT here is incorret.
+ * Instead simply lookup the dir_index_item for this entry so we can
+ * remove it. Otherwise we know we have a ref to the root and we can
+ * call btrfs_del_root_ref, and it _shouldn't_ fail.
+ */
+ if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
di = btrfs_search_dir_index_item(root, path, dir_ino,
name, name_len);
if (IS_ERR_OR_NULL(di)) {
@@ -4292,8 +4307,16 @@ static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
index = key.offset;
+ btrfs_release_path(path);
+ } else {
+ ret = btrfs_del_root_ref(trans, objectid,
+ root->root_key.objectid, dir_ino,
+ &index, name, name_len);
+ if (ret) {
+ btrfs_abort_transaction(trans, ret);
+ goto out;
+ }
}
- btrfs_release_path(path);
ret = btrfs_delete_delayed_dir_index(trans, BTRFS_I(dir), index);
if (ret) {
@@ -4487,8 +4510,7 @@ int btrfs_delete_subvolume(struct inode *dir, struct dentry *dentry)
btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
- ret = btrfs_unlink_subvol(trans, dir, dest->root_key.objectid,
- dentry->d_name.name, dentry->d_name.len);
+ ret = btrfs_unlink_subvol(trans, dir, dentry);
if (ret) {
err = ret;
btrfs_abort_transaction(trans, ret);
@@ -4583,10 +4605,7 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
return PTR_ERR(trans);
if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
- err = btrfs_unlink_subvol(trans, dir,
- BTRFS_I(inode)->location.objectid,
- dentry->d_name.name,
- dentry->d_name.len);
+ err = btrfs_unlink_subvol(trans, dir, dentry);
goto out;
}
@@ -9536,7 +9555,6 @@ static int btrfs_rename_exchange(struct inode *old_dir,
u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
u64 old_idx = 0;
u64 new_idx = 0;
- u64 root_objectid;
int ret;
bool root_log_pinned = false;
bool dest_log_pinned = false;
@@ -9642,10 +9660,7 @@ static int btrfs_rename_exchange(struct inode *old_dir,
/* src is a subvolume */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
- root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
- ret = btrfs_unlink_subvol(trans, old_dir, root_objectid,
- old_dentry->d_name.name,
- old_dentry->d_name.len);
+ ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
} else { /* src is an inode */
ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
BTRFS_I(old_dentry->d_inode),
@@ -9661,10 +9676,7 @@ static int btrfs_rename_exchange(struct inode *old_dir,
/* dest is a subvolume */
if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
- root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
- ret = btrfs_unlink_subvol(trans, new_dir, root_objectid,
- new_dentry->d_name.name,
- new_dentry->d_name.len);
+ ret = btrfs_unlink_subvol(trans, new_dir, new_dentry);
} else { /* dest is an inode */
ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
BTRFS_I(new_dentry->d_inode),
@@ -9862,7 +9874,6 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_inode = d_inode(new_dentry);
struct inode *old_inode = d_inode(old_dentry);
u64 index = 0;
- u64 root_objectid;
int ret;
u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
bool log_pinned = false;
@@ -9970,10 +9981,7 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
BTRFS_I(old_inode), 1);
if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
- root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
- ret = btrfs_unlink_subvol(trans, old_dir, root_objectid,
- old_dentry->d_name.name,
- old_dentry->d_name.len);
+ ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
} else {
ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
BTRFS_I(d_inode(old_dentry)),
@@ -9992,10 +10000,7 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
new_inode->i_ctime = current_time(new_inode);
if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
- root_objectid = BTRFS_I(new_inode)->location.objectid;
- ret = btrfs_unlink_subvol(trans, new_dir, root_objectid,
- new_dentry->d_name.name,
- new_dentry->d_name.len);
+ ret = btrfs_unlink_subvol(trans, new_dir, new_dentry);
BUG_ON(new_inode->i_nlink == 0);
} else {
ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 18e328ce4b54..12ae31e1813e 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4252,7 +4252,19 @@ static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
&sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
0);
- if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
+ /*
+ * Copy scrub args to user space even if btrfs_scrub_dev() returned an
+ * error. This is important as it allows user space to know how much
+ * progress scrub has done. For example, if scrub is canceled we get
+ * -ECANCELED from btrfs_scrub_dev() and return that error back to user
+ * space. Later user space can inspect the progress from the structure
+ * btrfs_ioctl_scrub_args and resume scrub from where it left off
+ * previously (btrfs-progs does this).
+ * If we fail to copy the btrfs_ioctl_scrub_args structure to user space
+ * then return -EFAULT to signal the structure was not copied or it may
+ * be corrupt and unreliable due to a partial copy.
+ */
+ if (copy_to_user(arg, sa, sizeof(*sa)))
ret = -EFAULT;
if (!(sa->flags & BTRFS_SCRUB_READONLY))
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index d4282e12f2a6..39fc8c3d3a75 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2423,8 +2423,12 @@ int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr,
u64 nr_old_roots = 0;
int ret = 0;
+ /*
+ * If quotas get disabled meanwhile, the resouces need to be freed and
+ * we can't just exit here.
+ */
if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
- return 0;
+ goto out_free;
if (new_roots) {
if (!maybe_fs_roots(new_roots))
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index c58245797f30..da5abd62db22 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -517,6 +517,34 @@ static int update_backref_cache(struct btrfs_trans_handle *trans,
return 1;
}
+static bool reloc_root_is_dead(struct btrfs_root *root)
+{
+ /*
+ * Pair with set_bit/clear_bit in clean_dirty_subvols and
+ * btrfs_update_reloc_root. We need to see the updated bit before
+ * trying to access reloc_root
+ */
+ smp_rmb();
+ if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state))
+ return true;
+ return false;
+}
+
+/*
+ * Check if this subvolume tree has valid reloc tree.
+ *
+ * Reloc tree after swap is considered dead, thus not considered as valid.
+ * This is enough for most callers, as they don't distinguish dead reloc root
+ * from no reloc root. But should_ignore_root() below is a special case.
+ */
+static bool have_reloc_root(struct btrfs_root *root)
+{
+ if (reloc_root_is_dead(root))
+ return false;
+ if (!root->reloc_root)
+ return false;
+ return true;
+}
static int should_ignore_root(struct btrfs_root *root)
{
@@ -525,6 +553,10 @@ static int should_ignore_root(struct btrfs_root *root)
if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
return 0;
+ /* This root has been merged with its reloc tree, we can ignore it */
+ if (reloc_root_is_dead(root))
+ return 1;
+
reloc_root = root->reloc_root;
if (!reloc_root)
return 0;
@@ -1439,7 +1471,7 @@ int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
* The subvolume has reloc tree but the swap is finished, no need to
* create/update the dead reloc tree
*/
- if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state))
+ if (reloc_root_is_dead(root))
return 0;
if (root->reloc_root) {
@@ -1478,8 +1510,7 @@ int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
struct btrfs_root_item *root_item;
int ret;
- if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state) ||
- !root->reloc_root)
+ if (!have_reloc_root(root))
goto out;
reloc_root = root->reloc_root;
@@ -1489,6 +1520,11 @@ int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
if (fs_info->reloc_ctl->merge_reloc_tree &&
btrfs_root_refs(root_item) == 0) {
set_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state);
+ /*
+ * Mark the tree as dead before we change reloc_root so
+ * have_reloc_root will not touch it from now on.
+ */
+ smp_wmb();
__del_reloc_root(reloc_root);
}
@@ -2201,6 +2237,11 @@ static int clean_dirty_subvols(struct reloc_control *rc)
if (ret2 < 0 && !ret)
ret = ret2;
}
+ /*
+ * Need barrier to ensure clear_bit() only happens after
+ * root->reloc_root = NULL. Pairs with have_reloc_root.
+ */
+ smp_wmb();
clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state);
btrfs_put_fs_root(root);
} else {
@@ -4718,7 +4759,7 @@ void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending,
struct btrfs_root *root = pending->root;
struct reloc_control *rc = root->fs_info->reloc_ctl;
- if (!root->reloc_root || !rc)
+ if (!rc || !have_reloc_root(root))
return;
if (!rc->merge_reloc_tree)
@@ -4752,7 +4793,7 @@ int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
struct reloc_control *rc = root->fs_info->reloc_ctl;
int ret;
- if (!root->reloc_root || !rc)
+ if (!rc || !have_reloc_root(root))
return 0;
rc = root->fs_info->reloc_ctl;
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 3b17b647d002..612411c74550 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -376,11 +376,13 @@ again:
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_root_ref);
-
- WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid);
- WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len);
ptr = (unsigned long)(ref + 1);
- WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len));
+ if ((btrfs_root_ref_dirid(leaf, ref) != dirid) ||
+ (btrfs_root_ref_name_len(leaf, ref) != name_len) ||
+ memcmp_extent_buffer(leaf, name, ptr, name_len)) {
+ err = -ENOENT;
+ goto out;
+ }
*sequence = btrfs_root_ref_sequence(leaf, ref);
ret = btrfs_del_item(trans, tree_root, path);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index a6d3f08bfff3..9b78e720c697 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3881,7 +3881,11 @@ int btrfs_balance(struct btrfs_fs_info *fs_info,
}
}
- num_devices = btrfs_num_devices(fs_info);
+ /*
+ * rw_devices will not change at the moment, device add/delete/replace
+ * are excluded by EXCL_OP
+ */
+ num_devices = fs_info->fs_devices->rw_devices;
/*
* SINGLE profile on-disk has no profile bit, but in-memory we have a

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