fs/btrfs/extent_io.c:5966:7: warning: Local variable 'ret' shadows outer variable [shadowVariable]

From: kernel test robot
Date: Tue Jun 28 2022 - 00:33:27 EST

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tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 941e3e7912696b9fbe3586083a7c2e102cee7a87
commit: dd137dd1f2d719682b522d4eabe6dec461b7d6fa btrfs: factor out allocating an array of pages
date: 6 weeks ago
compiler: nios2-linux-gcc (GCC) 11.3.0
reproduce (cppcheck warning):
# apt-get install cppcheck
git checkout dd137dd1f2d719682b522d4eabe6dec461b7d6fa
cppcheck --quiet --enable=style,performance,portability --template=gcc FILE

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>

cppcheck warnings: (new ones prefixed by >>)
>> fs/ext4/resize.c:383:7: warning: Local variable 'i' shadows outer variable [shadowVariable]
int i;
^
fs/ext4/resize.c:299:6: note: Shadowed declaration
int i;
^
fs/ext4/resize.c:383:7: note: Shadow variable
int i;
^
>> fs/btrfs/extent_io.c:5966:7: warning: Local variable 'ret' shadows outer variable [shadowVariable]
int ret;
^
fs/btrfs/extent_io.c:5945:6: note: Shadowed declaration
int ret;
^
fs/btrfs/extent_io.c:5966:7: note: Shadow variable
int ret;
^
>> fs/btrfs/inode.c:1004:13: warning: Local variable 'start' shadows outer variable [shadowVariable]
const u64 start = async_extent->start;
^
fs/btrfs/inode.c:926:6: note: Shadowed declaration
u64 start = async_extent->start;
^
fs/btrfs/inode.c:1004:13: note: Shadow variable
const u64 start = async_extent->start;
^
>> fs/btrfs/inode.c:1005:13: warning: Local variable 'end' shadows outer variable [shadowVariable]
const u64 end = start + async_extent->ram_size - 1;
^
fs/btrfs/inode.c:927:6: note: Shadowed declaration
u64 end = async_extent->start + async_extent->ram_size - 1;
^
fs/btrfs/inode.c:1005:13: note: Shadow variable
const u64 end = start + async_extent->ram_size - 1;
^

cppcheck possible warnings: (new ones prefixed by >>, may not real problems)

>> fs/exfat/namei.c:225:6: warning: Using argument hint_femp that points at uninitialized variable hint_femp [ctuuninitvar]
if (hint_femp->eidx != EXFAT_HINT_NONE) {
^
fs/exfat/namei.c:334:42: note: Calling function exfat_search_empty_slot, 2nd argument is uninitialized
while ((dentry = exfat_search_empty_slot(sb, &hint_femp, p_dir,
^
fs/exfat/namei.c:225:6: note: Using argument hint_femp
if (hint_femp->eidx != EXFAT_HINT_NONE) {
^
--
>> fs/ext4/resize.c:677:46: warning: The address of local variable 'block_bitmap' might be accessed at non-zero index. [objectIndex]
if (block == (&group_data[i].block_bitmap)[j]) {
^
fs/ext4/resize.c:677:18: note: Address of variable taken here.
if (block == (&group_data[i].block_bitmap)[j]) {
^
fs/ext4/resize.c:677:46: note: The address of local variable 'block_bitmap' might be accessed at non-zero index.
if (block == (&group_data[i].block_bitmap)[j]) {
^
fs/ext4/resize.c:690:41: warning: The address of local variable 'block_bitmap' might be accessed at non-zero index. [objectIndex]
start = (&group_data[i].block_bitmap)[j];
^
fs/ext4/resize.c:690:13: note: Address of variable taken here.
start = (&group_data[i].block_bitmap)[j];
^
fs/ext4/resize.c:690:41: note: The address of local variable 'block_bitmap' might be accessed at non-zero index.
start = (&group_data[i].block_bitmap)[j];
^
>> fs/ext4/resize.c:515:6: warning: Variable 'group_table_count' can be declared with const [constVariable]
int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group};
^
>> fs/ext4/ext4.h:593:2: warning: Shifting signed 32-bit value by 31 bits is implementation-defined behaviour [shiftTooManyBitsSigned]
CHECK_FLAG_VALUE(RESERVED);
^
>> fs/ext4/ext4.h:593:2: warning: Signed integer overflow for expression '1<<EXT4_INODE_RESERVED'. [integerOverflow]
CHECK_FLAG_VALUE(RESERVED);
^
>> fs/ext4/ext4_jbd2.h:402:9: warning: Variable '__ensure_end' is not assigned a value. [unassignedVariable]
return ext4_journal_ensure_credits_fn(handle, credits, credits,
^
>> fs/ext4/resize.c:427:9: warning: Variable '__ensure_end' is not assigned a value. [unassignedVariable]
return ext4_journal_ensure_credits_fn(handle, credits,
^
>> fs/ext4/resize.c:929:3: warning: Identical inner 'if' condition is always true. [identicalInnerCondition]
ext4_std_error(sb, err);
^
fs/ext4/resize.c:928:6: note: outer condition: err
if (err)
^
fs/ext4/resize.c:929:3: note: identical inner condition: err
ext4_std_error(sb, err);
^
fs/ext4/resize.c:1342:4: warning: Identical inner 'if' condition is always true. [identicalInnerCondition]
ext4_std_error(sb, err);
^
fs/ext4/resize.c:1341:7: note: outer condition: err
if (err) {
^
fs/ext4/resize.c:1342:4: note: identical inner condition: err
ext4_std_error(sb, err);
^
fs/ext4/resize.c:1921:3: warning: Identical inner 'if' condition is always true. [identicalInnerCondition]
ext4_std_error(sb, err);
^
fs/ext4/resize.c:1920:6: note: outer condition: err
if (err) {
^
fs/ext4/resize.c:1921:3: note: identical inner condition: err
ext4_std_error(sb, err);
^
fs/ext4/resize.c:1935:4: warning: Identical inner 'if' condition is always true. [identicalInnerCondition]
ext4_std_error(sb, err);
^
fs/ext4/resize.c:1934:7: note: outer condition: err
if (err)
^
fs/ext4/resize.c:1935:4: note: identical inner condition: err
ext4_std_error(sb, err);
^
>> fs/ext4/xattr.c:180:35: warning: Either the condition 'name_index>0' is redundant or the array 'ext4_xattr_handler_map[11]' is accessed at index 11, which is out of bounds. [arrayIndexOutOfBoundsCond]
handler = ext4_xattr_handler_map[name_index];
^
fs/ext4/xattr.c:179:17: note: Assuming that condition 'name_index>0' is not redundant
if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
^
fs/ext4/xattr.c:180:35: note: Array index out of bounds
handler = ext4_xattr_handler_map[name_index];
^
>> fs/ext4/xattr.h:156:70: warning: Parameter 'save' can be declared with const [constParameter]
static inline void ext4_write_unlock_xattr(struct inode *inode, int *save)
^
>> fs/ext4/xattr.c:185:64: warning: Parameter 'end' can be declared with const [constParameter]
ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end,
^
fs/ext4/xattr.c:284:10: warning: Parameter 'end' can be declared with const [constParameter]
void *end, int name_index, const char *name, int sorted)
^
>> fs/ext4/xattr.c:1313:33: warning: Parameter 'base' can be declared with const [constParameter]
size_t *min_offs, void *base, int *total)
^
>> fs/ext4/ext4.h:593:2: warning: Shifting signed 32-bit value by 31 bits is implementation-defined behaviour [shiftTooManyBitsSigned]
CHECK_FLAG_VALUE(RESERVED);
^
>> fs/ext4/ext4.h:593:2: warning: Signed integer overflow for expression '1<<EXT4_INODE_RESERVED'. [integerOverflow]
CHECK_FLAG_VALUE(RESERVED);
^
>> fs/ext4/ext4_jbd2.h:402:9: warning: Variable '__ensure_end' is not assigned a value. [unassignedVariable]
return ext4_journal_ensure_credits_fn(handle, credits, credits,
^
>> fs/ext4/xattr.c:1163:9: warning: Variable '__ensure_end' is not assigned a value. [unassignedVariable]
err = ext4_journal_ensure_credits_fn(handle, credits, credits,
^
>> fs/ext4/xattr.h:156:70: warning: Parameter 'save' can be declared with const [constParameter]
static inline void ext4_write_unlock_xattr(struct inode *inode, int *save)
^
>> fs/ext4/namei.c:1253:51: warning: Parameter 'hinfo' can be declared with const [constParameter]
unsigned blocksize, struct dx_hash_info *hinfo,
^
>> fs/ext4/namei.c:3564:67: warning: Parameter 'ent' can be declared with const [constParameter]
static void ext4_resetent(handle_t *handle, struct ext4_renament *ent,
^
>> fs/ext4/ext4.h:593:2: warning: Shifting signed 32-bit value by 31 bits is implementation-defined behaviour [shiftTooManyBitsSigned]
CHECK_FLAG_VALUE(RESERVED);
^
>> fs/ext4/ext4.h:593:2: warning: Signed integer overflow for expression '1<<EXT4_INODE_RESERVED'. [integerOverflow]
CHECK_FLAG_VALUE(RESERVED);
^
>> fs/ext4/ext4_jbd2.h:402:9: warning: Variable '__ensure_end' is not assigned a value. [unassignedVariable]
return ext4_journal_ensure_credits_fn(handle, credits, credits,
^
>> fs/ext4/namei.c:77:3: warning: Identical inner 'if' condition is always true. [identicalInnerCondition]
ext4_std_error(inode->i_sb, err);
^
fs/ext4/namei.c:75:6: note: outer condition: err
if (err) {
^
fs/ext4/namei.c:77:3: note: identical inner condition: err
ext4_std_error(inode->i_sb, err);
^
fs/ext4/namei.c:2118:3: warning: Identical inner 'if' condition is always true. [identicalInnerCondition]
ext4_std_error(dir->i_sb, err);
^
fs/ext4/namei.c:2117:6: note: outer condition: err
if (err) {
^
fs/ext4/namei.c:2118:3: note: identical inner condition: err
ext4_std_error(dir->i_sb, err);
^
fs/ext4/namei.c:2143:3: warning: Identical inner 'if' condition is always true. [identicalInnerCondition]
ext4_std_error(dir->i_sb, err);
^
fs/ext4/namei.c:2142:6: note: outer condition: err
if (err)
^
fs/ext4/namei.c:2143:3: note: identical inner condition: err
ext4_std_error(dir->i_sb, err);
^
fs/ext4/namei.c:2177:3: warning: Identical inner 'if' condition is always true. [identicalInnerCondition]
ext4_std_error(dir->i_sb, retval);
^
fs/ext4/namei.c:2176:6: note: outer condition: retval
if (retval) {
^
fs/ext4/namei.c:2177:3: note: identical inner condition: retval
ext4_std_error(dir->i_sb, retval);
^
fs/ext4/namei.c:3530:3: warning: Identical inner 'if' condition is always true. [identicalInnerCondition]
ext4_std_error(ent->dir->i_sb, retval);
^
fs/ext4/namei.c:3529:6: note: outer condition: retval
if (retval) {
^
fs/ext4/namei.c:3530:3: note: identical inner condition: retval
ext4_std_error(ent->dir->i_sb, retval);
^
fs/ext4/namei.c:3581:3: warning: Identical inner 'if' condition is always true. [identicalInnerCondition]
ext4_std_error(old.dir->i_sb, retval);
^
fs/ext4/namei.c:3580:6: note: outer condition: retval
if (retval) {
^
fs/ext4/namei.c:3581:3: note: identical inner condition: retval
ext4_std_error(old.dir->i_sb, retval);
^
>> fs/ext4/namei.c:747:28: warning: Parameter 'target' can be declared with const [constParameter]
struct dx_entry *target,
^
fs/ext4/namei.c:623:26: warning: Parameter 'hinfo' can be declared with const [constParameter]
struct dx_hash_info *hinfo,
^
>> fs/btrfs/file.c:443:64: warning: Parameter 'pages' can be declared with const [constParameter]
int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages,
^
>> fs/btrfs/tree-log.h:52:28: warning: Uninitialized variables: ordered.file_offset, ordered.num_bytes, ordered.ram_bytes, ordered.disk_bytenr, ordered.disk_num_bytes, ordered.offset, ordered.bytes_left, ordered.outstanding_isize, ordered.truncated_len, ordered.flags, ordered.compress_type, ordered.qgroup_rsv, ordered.refs, ordered.inode, ordered.list, ordered.wait, ordered.rb_node, ordered.root_extent_list, ordered.work, ordered.completion, ordered.flush_work, ordered.work_list, ordered.physical, ordered.bdev [uninitvar]
btrfs_put_ordered_extent(ordered);
^
>> fs/btrfs/file.c:66:6: warning: Using argument defrag1 that points at uninitialized variable tmp [ctuuninitvar]
if (defrag1->root > defrag2->root)
^
fs/btrfs/file.c:216:38: note: Calling function __compare_inode_defrag, 1st argument is uninitialized
if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
^
fs/btrfs/file.c:66:6: note: Using argument defrag1
if (defrag1->root > defrag2->root)
^
>> fs/ext4/xattr.h:156:70: warning: Parameter 'save' can be declared with const [constParameter]
static inline void ext4_write_unlock_xattr(struct inode *inode, int *save)
^
>> fs/ext4/ext4.h:593:2: warning: Shifting signed 32-bit value by 31 bits is implementation-defined behaviour [shiftTooManyBitsSigned]
CHECK_FLAG_VALUE(RESERVED);
^
>> fs/ext4/ext4.h:593:2: warning: Signed integer overflow for expression '1<<EXT4_INODE_RESERVED'. [integerOverflow]
CHECK_FLAG_VALUE(RESERVED);
^
>> fs/ext4/ext4_jbd2.h:402:9: warning: Variable '__ensure_end' is not assigned a value. [unassignedVariable]
return ext4_journal_ensure_credits_fn(handle, credits, credits,
^
>> fs/ext4/inode.c:5530:3: warning: Identical inner 'if' condition is always true. [identicalInnerCondition]
ext4_std_error(inode->i_sb, error);
^
fs/ext4/inode.c:5529:7: note: outer condition: error
if (error)
^
fs/ext4/inode.c:5530:3: note: identical inner condition: error
ext4_std_error(inode->i_sb, error);
^
>> fs/btrfs/extent_io.c:369:26: warning: Parameter 'p_in' can be declared with const [constParameter]
struct rb_node ***p_in,
^
>> fs/btrfs/extent_io.c:370:25: warning: Parameter 'parent_in' can be declared with const [constParameter]
struct rb_node **parent_in)
^
>> fs/btrfs/extent_io.c:1823:30: warning: Parameter 'mapping' can be declared with const [constParameter]
struct address_space *mapping,
^
>> fs/btrfs/extent_io.c:1824:40: warning: Parameter 'locked_page' can be declared with const [constParameter]
struct page *page, struct page *locked_page,
^
>> fs/btrfs/extent_io.c:6066:16: warning: Parameter 'accessed' can be declared with const [constParameter]
struct page *accessed)
^
>> fs/btrfs/inode.c:2188:21: warning: Parameter 'bits' can be declared with const [constParameter]
unsigned *bits)
^
fs/btrfs/inode.c:2239:44: warning: Parameter 'bits' can be declared with const [constParameter]
struct extent_state *state, unsigned *bits)
^
>> fs/btrfs/inode.c:256:19: warning: Parameter 'compressed_pages' can be declared with const [constParameter]
struct page **compressed_pages,
^
>> fs/btrfs/inode.c:5944:70: warning: Parameter 'now' can be declared with const [constParameter]
static int btrfs_update_time(struct inode *inode, struct timespec64 *now,
^
>> fs/btrfs/tree-log.h:52:28: warning: Uninitialized variables: ordered.file_offset, ordered.num_bytes, ordered.ram_bytes, ordered.disk_bytenr, ordered.disk_num_bytes, ordered.offset, ordered.bytes_left, ordered.outstanding_isize, ordered.truncated_len, ordered.flags, ordered.compress_type, ordered.qgroup_rsv, ordered.refs, ordered.inode, ordered.list, ordered.wait, ordered.rb_node, ordered.root_extent_list, ordered.work, ordered.completion, ordered.flush_work, ordered.work_list, ordered.physical, ordered.bdev [uninitvar]
btrfs_put_ordered_extent(ordered);
^
>> fs/btrfs/inode.c:2605:16: warning: Uninitialized variable: sum->bytenr [uninitvar]
sum->bytenr);
^

vim +/ret +5966 fs/btrfs/extent_io.c

5939
5940 struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src)
5941 {
5942 int i;
5943 struct extent_buffer *new;
5944 int num_pages = num_extent_pages(src);
5945 int ret;
5946
5947 new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
5948 if (new == NULL)
5949 return NULL;
5950
5951 /*
5952 * Set UNMAPPED before calling btrfs_release_extent_buffer(), as
5953 * btrfs_release_extent_buffer() have different behavior for
5954 * UNMAPPED subpage extent buffer.
5955 */
5956 set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags);
5957
5958 memset(new->pages, 0, sizeof(*new->pages) * num_pages);
5959 ret = btrfs_alloc_page_array(num_pages, new->pages);
5960 if (ret) {
5961 btrfs_release_extent_buffer(new);
5962 return NULL;
5963 }
5964
5965 for (i = 0; i < num_pages; i++) {
> 5966 int ret;
5967 struct page *p = new->pages[i];
5968
5969 ret = attach_extent_buffer_page(new, p, NULL);
5970 if (ret < 0) {
5971 btrfs_release_extent_buffer(new);
5972 return NULL;
5973 }
5974 WARN_ON(PageDirty(p));
5975 copy_page(page_address(p), page_address(src->pages[i]));
5976 }
5977 set_extent_buffer_uptodate(new);
5978
5979 return new;
5980 }
5981
5982 struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
5983 u64 start, unsigned long len)
5984 {
5985 struct extent_buffer *eb;
5986 int num_pages;
5987 int i;
5988 int ret;
5989
5990 eb = __alloc_extent_buffer(fs_info, start, len);
5991 if (!eb)
5992 return NULL;
5993
5994 num_pages = num_extent_pages(eb);
5995 ret = btrfs_alloc_page_array(num_pages, eb->pages);
5996 if (ret)
5997 goto err;
5998
5999 for (i = 0; i < num_pages; i++) {
6000 struct page *p = eb->pages[i];
6001
6002 ret = attach_extent_buffer_page(eb, p, NULL);
6003 if (ret < 0)
6004 goto err;
6005 }
6006
6007 set_extent_buffer_uptodate(eb);
6008 btrfs_set_header_nritems(eb, 0);
6009 set_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
6010
6011 return eb;
6012 err:
6013 for (i = 0; i < num_pages; i++) {
6014 if (eb->pages[i]) {
6015 detach_extent_buffer_page(eb, eb->pages[i]);
6016 __free_page(eb->pages[i]);
6017 }
6018 }
6019 __free_extent_buffer(eb);
6020 return NULL;
6021 }
6022
6023 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
6024 u64 start)
6025 {
6026 return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize);
6027 }
6028
6029 static void check_buffer_tree_ref(struct extent_buffer *eb)
6030 {
6031 int refs;
6032 /*
6033 * The TREE_REF bit is first set when the extent_buffer is added
6034 * to the radix tree. It is also reset, if unset, when a new reference
6035 * is created by find_extent_buffer.
6036 *
6037 * It is only cleared in two cases: freeing the last non-tree
6038 * reference to the extent_buffer when its STALE bit is set or
6039 * calling releasepage when the tree reference is the only reference.
6040 *
6041 * In both cases, care is taken to ensure that the extent_buffer's
6042 * pages are not under io. However, releasepage can be concurrently
6043 * called with creating new references, which is prone to race
6044 * conditions between the calls to check_buffer_tree_ref in those
6045 * codepaths and clearing TREE_REF in try_release_extent_buffer.
6046 *
6047 * The actual lifetime of the extent_buffer in the radix tree is
6048 * adequately protected by the refcount, but the TREE_REF bit and
6049 * its corresponding reference are not. To protect against this
6050 * class of races, we call check_buffer_tree_ref from the codepaths
6051 * which trigger io after they set eb->io_pages. Note that once io is
6052 * initiated, TREE_REF can no longer be cleared, so that is the
6053 * moment at which any such race is best fixed.
6054 */
6055 refs = atomic_read(&eb->refs);
6056 if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
6057 return;
6058
6059 spin_lock(&eb->refs_lock);
6060 if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
6061 atomic_inc(&eb->refs);
6062 spin_unlock(&eb->refs_lock);
6063 }
6064
6065 static void mark_extent_buffer_accessed(struct extent_buffer *eb,
> 6066 struct page *accessed)
6067 {
6068 int num_pages, i;
6069
6070 check_buffer_tree_ref(eb);
6071
6072 num_pages = num_extent_pages(eb);
6073 for (i = 0; i < num_pages; i++) {
6074 struct page *p = eb->pages[i];
6075
6076 if (p != accessed)
6077 mark_page_accessed(p);
6078 }
6079 }
6080

--
0-DAY CI Kernel Test Service
https://01.org/lkp

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