btrfs: fix qgroup_free_reserved_data int overflow

commit 9e65bfca24cf1d77e4a5c7a170db5867377b3fe7 upstream.

The reserved data counter and input parameter is a u64, but we
inadvertently accumulate it in an int. Overflowing that int results in
freeing the wrong amount of data and breaking reserve accounting.

Unfortunately, this overflow rot spreads from there, as the qgroup
release/free functions rely on returning an int to take advantage of
negative values for error codes.

Therefore, the full fix is to return the "released" or "freed" amount by
a u64 argument and to return 0 or negative error code via the return
value.

Most of the call sites simply ignore the return value, though some
of them handle the error and count the returned bytes. Change all of
them accordingly.

CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/btrfs/delalloc-space.c b/fs/btrfs/delalloc-space.c
index 0d105ed1b8defc8b85de5f40a96a886777b5b1a1..eef341bbcc60e7291893446a1cf1423a0d61ced7 100644 (file)
--- a/fs/btrfs/delalloc-space.c
+++ b/fs/btrfs/delalloc-space.c
@@ -199,7 +199,7 @@ void btrfs_free_reserved_data_space(struct btrfs_inode *inode,
        start = round_down(start, fs_info->sectorsize);
 
        btrfs_free_reserved_data_space_noquota(fs_info, len);
-       btrfs_qgroup_free_data(inode, reserved, start, len);
+       btrfs_qgroup_free_data(inode, reserved, start, len, NULL);
 }
 
 /*

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 23a145ca945730db1bf7e1c5652475dd7356b49a..c997b790568fabaa27c9cf985f6257f992453187 100644 (file)
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -3187,7 +3187,7 @@ static long btrfs_fallocate(struct file *file, int mode,
                        qgroup_reserved -= range->len;
                } else if (qgroup_reserved > 0) {
                        btrfs_qgroup_free_data(BTRFS_I(inode), data_reserved,
-                                              range->start, range->len);
+                                              range->start, range->len, NULL);
                        qgroup_reserved -= range->len;
                }
                list_del(&range->list);

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c92c589b454d83178327cb326af93dee45aa63fa..7bf5c2c1a54d8f2658ba14075e3fb8bd6f0f1ff8 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -687,7 +687,7 @@ static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 size,
         * And at reserve time, it's always aligned to page size, so
         * just free one page here.
         */
-       btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
+       btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE, NULL);
        btrfs_free_path(path);
        btrfs_end_transaction(trans);
        return ret;
@@ -5129,7 +5129,7 @@ static void evict_inode_truncate_pages(struct inode *inode)
                 */
                if (state_flags & EXTENT_DELALLOC)
                        btrfs_qgroup_free_data(BTRFS_I(inode), NULL, start,
-                                              end - start + 1);
+                                              end - start + 1, NULL);
 
                clear_extent_bit(io_tree, start, end,
                                 EXTENT_CLEAR_ALL_BITS | EXTENT_DO_ACCOUNTING,
@@ -8051,7 +8051,7 @@ static void btrfs_invalidate_folio(struct folio *folio, size_t offset,
                 *    reserved data space.
                 *    Since the IO will never happen for this page.
                 */
-               btrfs_qgroup_free_data(inode, NULL, cur, range_end + 1 - cur);
+               btrfs_qgroup_free_data(inode, NULL, cur, range_end + 1 - cur, NULL);
                if (!inode_evicting) {
                        clear_extent_bit(tree, cur, range_end, EXTENT_LOCKED |
                                 EXTENT_DELALLOC | EXTENT_UPTODATE |
@@ -9481,7 +9481,7 @@ static struct btrfs_trans_handle *insert_prealloc_file_extent(
        struct btrfs_path *path;
        u64 start = ins->objectid;
        u64 len = ins->offset;
-       int qgroup_released;
+       u64 qgroup_released = 0;
        int ret;
 
        memset(&stack_fi, 0, sizeof(stack_fi));
@@ -9494,9 +9494,9 @@ static struct btrfs_trans_handle *insert_prealloc_file_extent(
        btrfs_set_stack_file_extent_compression(&stack_fi, BTRFS_COMPRESS_NONE);
        /* Encryption and other encoding is reserved and all 0 */
 
-       qgroup_released = btrfs_qgroup_release_data(inode, file_offset, len);
-       if (qgroup_released < 0)
-               return ERR_PTR(qgroup_released);
+       ret = btrfs_qgroup_release_data(inode, file_offset, len, &qgroup_released);
+       if (ret < 0)
+               return ERR_PTR(ret);
 
        if (trans) {
                ret = insert_reserved_file_extent(trans, inode,
@@ -10391,7 +10391,7 @@ ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
        btrfs_delalloc_release_metadata(inode, disk_num_bytes, ret < 0);
 out_qgroup_free_data:
        if (ret < 0)
-               btrfs_qgroup_free_data(inode, data_reserved, start, num_bytes);
+               btrfs_qgroup_free_data(inode, data_reserved, start, num_bytes, NULL);
 out_free_data_space:
        /*
         * If btrfs_reserve_extent() succeeded, then we already decremented

diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 0fa0bc13e8ac4fa1bcd78a7c6f340d733b85a205..2b8ff8b53af0448e07415c69e5b160aee91cfc17 100644 (file)
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -153,11 +153,12 @@ static struct btrfs_ordered_extent *alloc_ordered_extent(
 {
        struct btrfs_ordered_extent *entry;
        int ret;
+       u64 qgroup_rsv = 0;
 
        if (flags &
            ((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
                /* For nocow write, we can release the qgroup rsv right now */
-               ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes);
+               ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes, &qgroup_rsv);
                if (ret < 0)
                        return ERR_PTR(ret);
        } else {
@@ -165,7 +166,7 @@ static struct btrfs_ordered_extent *alloc_ordered_extent(
                 * The ordered extent has reserved qgroup space, release now
                 * and pass the reserved number for qgroup_record to free.
                 */
-               ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes);
+               ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes, &qgroup_rsv);
                if (ret < 0)
                        return ERR_PTR(ret);
        }
@@ -183,7 +184,7 @@ static struct btrfs_ordered_extent *alloc_ordered_extent(
        entry->inode = igrab(&inode->vfs_inode);
        entry->compress_type = compress_type;
        entry->truncated_len = (u64)-1;
-       entry->qgroup_rsv = ret;
+       entry->qgroup_rsv = qgroup_rsv;
        entry->flags = flags;
        refcount_set(&entry->refs, 1);
        init_waitqueue_head(&entry->wait);

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index bdaebb9fc6899ffd57d8694b59c751ddbb2ec522..7c92494381549e88a104c34c9a2ac15cc9c3152e 100644 (file)
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -3855,13 +3855,14 @@ int btrfs_qgroup_reserve_data(struct btrfs_inode *inode,
 
 /* Free ranges specified by @reserved, normally in error path */
 static int qgroup_free_reserved_data(struct btrfs_inode *inode,
-                       struct extent_changeset *reserved, u64 start, u64 len)
+                                    struct extent_changeset *reserved,
+                                    u64 start, u64 len, u64 *freed_ret)
 {
        struct btrfs_root *root = inode->root;
        struct ulist_node *unode;
        struct ulist_iterator uiter;
        struct extent_changeset changeset;
-       int freed = 0;
+       u64 freed = 0;
        int ret;
 
        extent_changeset_init(&changeset);
@@ -3902,7 +3903,9 @@ static int qgroup_free_reserved_data(struct btrfs_inode *inode,
        }
        btrfs_qgroup_free_refroot(root->fs_info, root->root_key.objectid, freed,
                                  BTRFS_QGROUP_RSV_DATA);
-       ret = freed;
+       if (freed_ret)
+               *freed_ret = freed;
+       ret = 0;
 out:
        extent_changeset_release(&changeset);
        return ret;
@@ -3910,7 +3913,7 @@ static int qgroup_free_reserved_data(struct btrfs_inode *inode,
 
 static int __btrfs_qgroup_release_data(struct btrfs_inode *inode,
                        struct extent_changeset *reserved, u64 start, u64 len,
-                       int free)
+                       u64 *released, int free)
 {
        struct extent_changeset changeset;
        int trace_op = QGROUP_RELEASE;
@@ -3922,7 +3925,7 @@ static int __btrfs_qgroup_release_data(struct btrfs_inode *inode,
        /* In release case, we shouldn't have @reserved */
        WARN_ON(!free && reserved);
        if (free && reserved)
-               return qgroup_free_reserved_data(inode, reserved, start, len);
+               return qgroup_free_reserved_data(inode, reserved, start, len, released);
        extent_changeset_init(&changeset);
        ret = clear_record_extent_bits(&inode->io_tree, start, start + len -1,
                                       EXTENT_QGROUP_RESERVED, &changeset);
@@ -3937,7 +3940,8 @@ static int __btrfs_qgroup_release_data(struct btrfs_inode *inode,
                btrfs_qgroup_free_refroot(inode->root->fs_info,
                                inode->root->root_key.objectid,
                                changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA);
-       ret = changeset.bytes_changed;
+       if (released)
+               *released = changeset.bytes_changed;
 out:
        extent_changeset_release(&changeset);
        return ret;
@@ -3956,9 +3960,10 @@ static int __btrfs_qgroup_release_data(struct btrfs_inode *inode,
  * NOTE: This function may sleep for memory allocation.
  */
 int btrfs_qgroup_free_data(struct btrfs_inode *inode,
-                       struct extent_changeset *reserved, u64 start, u64 len)
+                          struct extent_changeset *reserved,
+                          u64 start, u64 len, u64 *freed)
 {
-       return __btrfs_qgroup_release_data(inode, reserved, start, len, 1);
+       return __btrfs_qgroup_release_data(inode, reserved, start, len, freed, 1);
 }
 
 /*
@@ -3976,9 +3981,9 @@ int btrfs_qgroup_free_data(struct btrfs_inode *inode,
  *
  * NOTE: This function may sleep for memory allocation.
  */
-int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len)
+int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len, u64 *released)
 {
-       return __btrfs_qgroup_release_data(inode, NULL, start, len, 0);
+       return __btrfs_qgroup_release_data(inode, NULL, start, len, released, 0);
 }
 
 static void add_root_meta_rsv(struct btrfs_root *root, int num_bytes,

diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h
index 7bffa10589d6b244135d150c6f4e6ae092f4ad32..104c9bd3c3379f301d1a07aa93484cd4520c6122 100644 (file)
--- a/fs/btrfs/qgroup.h
+++ b/fs/btrfs/qgroup.h
@@ -363,10 +363,10 @@ int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
 /* New io_tree based accurate qgroup reserve API */
 int btrfs_qgroup_reserve_data(struct btrfs_inode *inode,
                        struct extent_changeset **reserved, u64 start, u64 len);
-int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len);
+int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len, u64 *released);
 int btrfs_qgroup_free_data(struct btrfs_inode *inode,
                           struct extent_changeset *reserved, u64 start,
-                          u64 len);
+                          u64 len, u64 *freed);
 int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,
                              enum btrfs_qgroup_rsv_type type, bool enforce);
 int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes,