[PATCH] hfs/hfsplus: use WARN_ON for sanity check

From: Arnd Bergmann
Date: Mon Mar 22 2021 - 18:34:16 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

gcc warns about a couple of instances in which a sanity check
exists but the author wasn't sure how to react to it failing,
which makes it look like a possible bug:

fs/hfsplus/inode.c: In function 'hfsplus_cat_read_inode':
fs/hfsplus/inode.c:503:37: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
503 | /* panic? */;
| ^
fs/hfsplus/inode.c:524:37: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
524 | /* panic? */;
| ^
fs/hfsplus/inode.c: In function 'hfsplus_cat_write_inode':
fs/hfsplus/inode.c:582:37: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
582 | /* panic? */;
| ^
fs/hfsplus/inode.c:608:37: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
608 | /* panic? */;
| ^
fs/hfs/inode.c: In function 'hfs_write_inode':
fs/hfs/inode.c:464:37: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
464 | /* panic? */;
| ^
fs/hfs/inode.c:485:37: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
485 | /* panic? */;
| ^

panic() is probably not the correct choice here, but a WARN_ON
seems appropriate and avoids the compile-time warning.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
fs/hfs/inode.c | 6 ++----
fs/hfsplus/inode.c | 12 ++++--------
2 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 3fc5cb346586..4c5610b5356f 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -460,8 +460,7 @@ int hfs_write_inode(struct inode *inode, struct writeback_control *wbc)
goto out;

if (S_ISDIR(main_inode->i_mode)) {
- if (fd.entrylength < sizeof(struct hfs_cat_dir))
- /* panic? */;
+ WARN_ON(fd.entrylength < sizeof(struct hfs_cat_dir));
hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
sizeof(struct hfs_cat_dir));
if (rec.type != HFS_CDR_DIR ||
@@ -481,8 +480,7 @@ int hfs_write_inode(struct inode *inode, struct writeback_control *wbc)
hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
sizeof(struct hfs_cat_file));
} else {
- if (fd.entrylength < sizeof(struct hfs_cat_file))
- /* panic? */;
+ WARN_ON(fd.entrylength < sizeof(struct hfs_cat_file));
hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
sizeof(struct hfs_cat_file));
if (rec.type != HFS_CDR_FIL ||
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index 078c5c8a5156..6bcb0d935472 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -499,8 +499,7 @@ int hfsplus_cat_read_inode(struct inode *inode, struct hfs_find_data *fd)
if (type == HFSPLUS_FOLDER) {
struct hfsplus_cat_folder *folder = &entry.folder;

- if (fd->entrylength < sizeof(struct hfsplus_cat_folder))
- /* panic? */;
+ WARN_ON(fd->entrylength < sizeof(struct hfsplus_cat_folder));
hfs_bnode_read(fd->bnode, &entry, fd->entryoffset,
sizeof(struct hfsplus_cat_folder));
hfsplus_get_perms(inode, &folder->permissions, 1);
@@ -520,8 +519,7 @@ int hfsplus_cat_read_inode(struct inode *inode, struct hfs_find_data *fd)
} else if (type == HFSPLUS_FILE) {
struct hfsplus_cat_file *file = &entry.file;

- if (fd->entrylength < sizeof(struct hfsplus_cat_file))
- /* panic? */;
+ WARN_ON(fd->entrylength < sizeof(struct hfsplus_cat_file));
hfs_bnode_read(fd->bnode, &entry, fd->entryoffset,
sizeof(struct hfsplus_cat_file));

@@ -578,8 +576,7 @@ int hfsplus_cat_write_inode(struct inode *inode)
if (S_ISDIR(main_inode->i_mode)) {
struct hfsplus_cat_folder *folder = &entry.folder;

- if (fd.entrylength < sizeof(struct hfsplus_cat_folder))
- /* panic? */;
+ WARN_ON(fd.entrylength < sizeof(struct hfsplus_cat_folder));
hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
sizeof(struct hfsplus_cat_folder));
/* simple node checks? */
@@ -604,8 +601,7 @@ int hfsplus_cat_write_inode(struct inode *inode)
} else {
struct hfsplus_cat_file *file = &entry.file;

- if (fd.entrylength < sizeof(struct hfsplus_cat_file))
- /* panic? */;
+ WARN_ON(fd.entrylength < sizeof(struct hfsplus_cat_file));
hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
sizeof(struct hfsplus_cat_file));
hfsplus_inode_write_fork(inode, &file->data_fork);
--
2.29.2