Re: [PATCH] x86/uaccess: small optimization in unsafe_copy_to_user()

From: Al Viro
Date: Sat Apr 17 2021 - 21:16:13 EST

On Sat, Apr 17, 2021 at 03:11:49PM -0700, Linus Torvalds wrote:
> On Sat, Apr 17, 2021 at 1:35 PM Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
> >
> > No, wait - we have non-NULL buf->prev_reclen, so we'll hit
> > with buf->error completely ignored. Nevermind.
>
> Yeah, I'm pretty sure I even tested that -EINTR case at one point.
>
> Of course, it could easily have gotten broken again, so that's not a
> strong argument.
>
> That said, the "buf->err" handling has always been very confusing, and
> it would be lovely to get rid of that confusion.
>
> I don't remember why we did it that way, but I think it's because
> low-level filesystems ended up changing the error that the filldir()
> function returned or something like that.

Propagating errors from e.g. filldir() out through ->iterate() instances
turns out to be painful. If anything, considering that there's a lot
more ->iterate/->iterate_shared instances that ->actor ones, it would
make sense to change the calling conventions for the latter. IOW,
stop pretending that they return an error value and just have them
return a bool: "should the caller keep going".

Here's what I've got sitting in a local branch; not sure if it would
be better to invert the rules, though - I went for "should we keep
going", but we could do "should we stop" instead.

Change calling conventions for filldir_t

filldir_t instances (directory iterators callbacks) used to return 0 for
"OK, keep going" or -E... for "stop". Note that it's *NOT* how the
error values are reported - the rules for those are callback-dependent
and ->iterate{,_shared}() instances only care about zero vs. non-zero
(look at emit_dir() and friends).

So let's just return bool - it's less confusing that way.

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst
index 0302035781be..268c2ac616d1 100644
--- a/Documentation/filesystems/porting.rst
+++ b/Documentation/filesystems/porting.rst
@@ -890,3 +890,14 @@ been called or returned with non -EIOCBQUEUED code.

mnt_want_write_file() can now only be paired with mnt_drop_write_file(),
whereas previously it could be paired with mnt_drop_write() as well.
+
+---
+
+*mandatory*
+
+filldir_t (readdir callbacks) calling conventions have changed. Instead of
+returning 0 or -E... it returns bool now. true means "keep going" (as 0 used
+to to) and false - "no more" (as -E... in old calling conventions). Rationale:
+callers never looked at specific -E... values anyway. ->iterate() and
+->iterate_shared() instance require no changes at all, all filldir_t ones in
+the tree converted.
diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index d5367a1c6300..6864794b663a 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -107,7 +107,7 @@ struct osf_dirent_callback {
int error;
};

-static int
+static bool
osf_filldir(struct dir_context *ctx, const char *name, int namlen,
loff_t offset, u64 ino, unsigned int d_type)
{
@@ -119,11 +119,11 @@ osf_filldir(struct dir_context *ctx, const char *name, int namlen,

buf->error = -EINVAL; /* only used if we fail */
if (reclen > buf->count)
- return -EINVAL;
+ return false;
d_ino = ino;
if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
buf->error = -EOVERFLOW;
- return -EOVERFLOW;
+ return false;
}
if (buf->basep) {
if (put_user(offset, buf->basep))
@@ -140,10 +140,10 @@ osf_filldir(struct dir_context *ctx, const char *name, int namlen,
dirent = (void __user *)dirent + reclen;
buf->dirent = dirent;
buf->count -= reclen;
- return 0;
+ return true;
Efault:
buf->error = -EFAULT;
- return -EFAULT;
+ return false;
}

SYSCALL_DEFINE4(osf_getdirentries, unsigned int, fd,
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index 714fcca9af99..aa3bdf389d47 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -24,9 +24,9 @@ static int afs_readdir(struct file *file, struct dir_context *ctx);
static int afs_d_revalidate(struct dentry *dentry, unsigned int flags);
static int afs_d_delete(const struct dentry *dentry);
static void afs_d_iput(struct dentry *dentry, struct inode *inode);
-static int afs_lookup_one_filldir(struct dir_context *ctx, const char *name, int nlen,
+static bool afs_lookup_one_filldir(struct dir_context *ctx, const char *name, int nlen,
loff_t fpos, u64 ino, unsigned dtype);
-static int afs_lookup_filldir(struct dir_context *ctx, const char *name, int nlen,
+static bool afs_lookup_filldir(struct dir_context *ctx, const char *name, int nlen,
loff_t fpos, u64 ino, unsigned dtype);
static int afs_create(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode, bool excl);
@@ -527,7 +527,7 @@ static int afs_readdir(struct file *file, struct dir_context *ctx)
* - if afs_dir_iterate_block() spots this function, it'll pass the FID
* uniquifier through dtype
*/
-static int afs_lookup_one_filldir(struct dir_context *ctx, const char *name,
+static bool afs_lookup_one_filldir(struct dir_context *ctx, const char *name,
int nlen, loff_t fpos, u64 ino, unsigned dtype)
{
struct afs_lookup_one_cookie *cookie =
@@ -543,16 +543,16 @@ static int afs_lookup_one_filldir(struct dir_context *ctx, const char *name,

if (cookie->name.len != nlen ||
memcmp(cookie->name.name, name, nlen) != 0) {
- _leave(" = 0 [no]");
- return 0;
+ _leave(" = true [keep looking]");
+ return true;
}

cookie->fid.vnode = ino;
cookie->fid.unique = dtype;
cookie->found = 1;

- _leave(" = -1 [found]");
- return -1;
+ _leave(" = false [found]");
+ return false;
}

/*
@@ -596,12 +596,11 @@ static int afs_do_lookup_one(struct inode *dir, struct dentry *dentry,
* - if afs_dir_iterate_block() spots this function, it'll pass the FID
* uniquifier through dtype
*/
-static int afs_lookup_filldir(struct dir_context *ctx, const char *name,
+static bool afs_lookup_filldir(struct dir_context *ctx, const char *name,
int nlen, loff_t fpos, u64 ino, unsigned dtype)
{
struct afs_lookup_cookie *cookie =
container_of(ctx, struct afs_lookup_cookie, ctx);
- int ret;

_enter("{%s,%u},%s,%u,,%llu,%u",
cookie->name.name, cookie->name.len, name, nlen,
@@ -623,12 +622,10 @@ static int afs_lookup_filldir(struct dir_context *ctx, const char *name,
cookie->fids[1].unique = dtype;
cookie->found = 1;
if (cookie->one_only)
- return -1;
+ return false;
}

- ret = cookie->nr_fids >= 50 ? -1 : 0;
- _leave(" = %d", ret);
- return ret;
+ return cookie->nr_fids < 50;
}

/*
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 5fb45d865ce5..a06810fc2bc8 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -53,7 +53,7 @@ struct ecryptfs_getdents_callback {
};

/* Inspired by generic filldir in fs/readdir.c */
-static int
+static bool
ecryptfs_filldir(struct dir_context *ctx, const char *lower_name,
int lower_namelen, loff_t offset, u64 ino, unsigned int d_type)
{
@@ -61,18 +61,19 @@ ecryptfs_filldir(struct dir_context *ctx, const char *lower_name,
container_of(ctx, struct ecryptfs_getdents_callback, ctx);
size_t name_size;
char *name;
- int rc;
+ int err;
+ bool res;

buf->filldir_called++;
- rc = ecryptfs_decode_and_decrypt_filename(&name, &name_size,
- buf->sb, lower_name,
- lower_namelen);
- if (rc) {
- if (rc != -EINVAL) {
+ err = ecryptfs_decode_and_decrypt_filename(&name, &name_size,
+ buf->sb, lower_name,
+ lower_namelen);
+ if (err) {
+ if (err != -EINVAL) {
ecryptfs_printk(KERN_DEBUG,
"%s: Error attempting to decode and decrypt filename [%s]; rc = [%d]\n",
- __func__, lower_name, rc);
- return rc;
+ __func__, lower_name, err);
+ return false;
}

/* Mask -EINVAL errors as these are most likely due a plaintext
@@ -81,16 +82,15 @@ ecryptfs_filldir(struct dir_context *ctx, const char *lower_name,
* the "lost+found" dentry in the root directory of an Ext4
* filesystem.
*/
- return 0;
+ return true;
}

buf->caller->pos = buf->ctx.pos;
- rc = !dir_emit(buf->caller, name, name_size, ino, d_type);
+ res = dir_emit(buf->caller, name, name_size, ino, d_type);
kfree(name);
- if (!rc)
+ if (res)
buf->entries_written++;
-
- return rc;
+ return res;
}

/**
@@ -111,14 +111,8 @@ static int ecryptfs_readdir(struct file *file, struct dir_context *ctx)
lower_file = ecryptfs_file_to_lower(file);
rc = iterate_dir(lower_file, &buf.ctx);
ctx->pos = buf.ctx.pos;
- if (rc < 0)
- goto out;
- if (buf.filldir_called && !buf.entries_written)
- goto out;
- if (rc >= 0)
- fsstack_copy_attr_atime(inode,
- file_inode(lower_file));
-out:
+ if (rc >= 0 && (buf.entries_written || !buf.filldir_called))
+ fsstack_copy_attr_atime(inode, file_inode(lower_file));
return rc;
}

diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 0106eba46d5a..88096d842d31 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -248,21 +248,20 @@ struct getdents_callback {
* A rather strange filldir function to capture
* the name matching the specified inode number.
*/
-static int filldir_one(struct dir_context *ctx, const char *name, int len,
+static bool filldir_one(struct dir_context *ctx, const char *name, int len,
loff_t pos, u64 ino, unsigned int d_type)
{
struct getdents_callback *buf =
container_of(ctx, struct getdents_callback, ctx);
- int result = 0;

buf->sequence++;
if (buf->ino == ino && len <= NAME_MAX) {
memcpy(buf->name, name, len);
buf->name[len] = '\0';
buf->found = 1;
- result = -1;
+ return false; // no more
}
- return result;
+ return true;
}

/**
diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index c4a274285858..f4366dc59f0e 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -705,7 +705,7 @@ static int fat_readdir(struct file *file, struct dir_context *ctx)
}

#define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type) \
-static int func(struct dir_context *ctx, const char *name, int name_len, \
+static bool func(struct dir_context *ctx, const char *name, int name_len, \
loff_t offset, u64 ino, unsigned int d_type) \
{ \
struct fat_ioctl_filldir_callback *buf = \
@@ -714,7 +714,7 @@ static int func(struct dir_context *ctx, const char *name, int name_len, \
struct dirent_type __user *d2 = d1 + 1; \
\
if (buf->result) \
- return -EINVAL; \
+ return false; \
buf->result++; \
\
if (name != NULL) { \
@@ -750,10 +750,10 @@ static int func(struct dir_context *ctx, const char *name, int name_len, \
put_user(short_len, &d1->d_reclen)) \
goto efault; \
} \
- return 0; \
+ return true; \
efault: \
buf->result = -EFAULT; \
- return -EFAULT; \
+ return false; \
}

FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir, __fat_dirent)
diff --git a/fs/gfs2/export.c b/fs/gfs2/export.c
index 756d05779200..f55d083f6709 100644
--- a/fs/gfs2/export.c
+++ b/fs/gfs2/export.c
@@ -66,7 +66,7 @@ struct get_name_filldir {
char *name;
};

-static int get_name_filldir(struct dir_context *ctx, const char *name,
+static bool get_name_filldir(struct dir_context *ctx, const char *name,
int length, loff_t offset, u64 inum,
unsigned int type)
{
@@ -74,12 +74,12 @@ static int get_name_filldir(struct dir_context *ctx, const char *name,
container_of(ctx, struct get_name_filldir, ctx);

if (inum != gnfd->inum.no_addr)
- return 0;
+ return true;

memcpy(gnfd->name, name, length);
gnfd->name[length] = 0;

- return 1;
+ return false; // no more
}

static int gfs2_get_name(struct dentry *parent, char *name,
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index 891395c6c7d3..1c54cd62ee49 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -266,7 +266,7 @@ struct nfs4_dir_ctx {
struct list_head names;
};

-static int
+static bool
nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen,
loff_t offset, u64 ino, unsigned int d_type)
{
@@ -275,14 +275,14 @@ nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen,
struct name_list *entry;

if (namlen != HEXDIR_LEN - 1)
- return 0;
+ return true;
entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
if (entry == NULL)
- return -ENOMEM;
+ return false;
memcpy(entry->name, name, HEXDIR_LEN - 1);
entry->name[HEXDIR_LEN - 1] = '\0';
list_add(&entry->list, &ctx->names);
- return 0;
+ return true;
}

static int
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index fd6be35a1642..6cde3be4fbfa 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1943,7 +1943,7 @@ struct readdir_data {
int full;
};

-static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
+static bool nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
int namlen, loff_t offset, u64 ino,
unsigned int d_type)
{
@@ -1955,7 +1955,7 @@ static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
if (buf->used + reclen > PAGE_SIZE) {
buf->full = 1;
- return -EINVAL;
+ return false;
}

de->namlen = namlen;
@@ -1965,7 +1965,7 @@ static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
memcpy(de->name, name, namlen);
buf->used += reclen;

- return 0;
+ return true;
}

static __be32 nfsd_buffered_readdir(struct file *file, nfsd_filldir_t func,
diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index bdfba9db558a..ec7854390dc6 100644
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -2034,7 +2034,7 @@ struct ocfs2_empty_dir_priv {
unsigned seen_other;
unsigned dx_dir;
};
-static int ocfs2_empty_dir_filldir(struct dir_context *ctx, const char *name,
+static bool ocfs2_empty_dir_filldir(struct dir_context *ctx, const char *name,
int name_len, loff_t pos, u64 ino,
unsigned type)
{
@@ -2054,7 +2054,7 @@ static int ocfs2_empty_dir_filldir(struct dir_context *ctx, const char *name,
*/
if (name_len == 1 && !strncmp(".", name, 1) && pos == 0) {
p->seen_dot = 1;
- return 0;
+ return true;
}

if (name_len == 2 && !strncmp("..", name, 2) &&
@@ -2062,13 +2062,13 @@ static int ocfs2_empty_dir_filldir(struct dir_context *ctx, const char *name,
p->seen_dot_dot = 1;

if (p->dx_dir && p->seen_dot)
- return 1;
+ return false;

- return 0;
+ return true;
}

p->seen_other = 1;
- return 1;
+ return false;
}

static int ocfs2_empty_dir_dx(struct inode *inode,
diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index db52e843002a..0c9fd036f4ab 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -2035,7 +2035,7 @@ struct ocfs2_orphan_filldir_priv {
enum ocfs2_orphan_reco_type orphan_reco_type;
};

-static int ocfs2_orphan_filldir(struct dir_context *ctx, const char *name,
+static bool ocfs2_orphan_filldir(struct dir_context *ctx, const char *name,
int name_len, loff_t pos, u64 ino,
unsigned type)
{
@@ -2044,21 +2044,21 @@ static int ocfs2_orphan_filldir(struct dir_context *ctx, const char *name,
struct inode *iter;

if (name_len == 1 && !strncmp(".", name, 1))
- return 0;
+ return true;
if (name_len == 2 && !strncmp("..", name, 2))
- return 0;
+ return true;

/* do not include dio entry in case of orphan scan */
if ((p->orphan_reco_type == ORPHAN_NO_NEED_TRUNCATE) &&
(!strncmp(name, OCFS2_DIO_ORPHAN_PREFIX,
OCFS2_DIO_ORPHAN_PREFIX_LEN)))
- return 0;
+ return true;

/* Skip bad inodes so that recovery can continue */
iter = ocfs2_iget(p->osb, ino,
OCFS2_FI_FLAG_ORPHAN_RECOVERY, 0);
if (IS_ERR(iter))
- return 0;
+ return true;

if (!strncmp(name, OCFS2_DIO_ORPHAN_PREFIX,
OCFS2_DIO_ORPHAN_PREFIX_LEN))
@@ -2068,7 +2068,7 @@ static int ocfs2_orphan_filldir(struct dir_context *ctx, const char *name,
* happen concurrently with unlink/rename */
if (OCFS2_I(iter)->ip_next_orphan) {
iput(iter);
- return 0;
+ return true;
}

trace_ocfs2_orphan_filldir((unsigned long long)OCFS2_I(iter)->ip_blkno);
@@ -2077,7 +2077,7 @@ static int ocfs2_orphan_filldir(struct dir_context *ctx, const char *name,
OCFS2_I(iter)->ip_next_orphan = p->head;
p->head = iter;

- return 0;
+ return true;
}

static int ocfs2_queue_orphans(struct ocfs2_super *osb,
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index f404a78e6b60..abe6d8cc1b0d 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -170,7 +170,7 @@ static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd,
return p;
}

-static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd,
+static bool ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd,
const char *name, int len, u64 ino,
unsigned int d_type)
{
@@ -179,22 +179,22 @@ static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd,
struct ovl_cache_entry *p;

if (ovl_cache_entry_find_link(name, len, &newp, &parent))
- return 0;
+ return true;

p = ovl_cache_entry_new(rdd, name, len, ino, d_type);
if (p == NULL) {
rdd->err = -ENOMEM;
- return -ENOMEM;
+ return false;
}

list_add_tail(&p->l_node, rdd->list);
rb_link_node(&p->node, parent, newp);
rb_insert_color(&p->node, rdd->root);

- return 0;
+ return true;
}

-static int ovl_fill_lowest(struct ovl_readdir_data *rdd,
+static bool ovl_fill_lowest(struct ovl_readdir_data *rdd,
const char *name, int namelen,
loff_t offset, u64 ino, unsigned int d_type)
{
@@ -211,7 +211,7 @@ static int ovl_fill_lowest(struct ovl_readdir_data *rdd,
list_add_tail(&p->l_node, &rdd->middle);
}

- return rdd->err;
+ return rdd->err == 0;
}

void ovl_cache_free(struct list_head *list)
@@ -250,7 +250,7 @@ static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry)
}
}

-static int ovl_fill_merge(struct dir_context *ctx, const char *name,
+static bool ovl_fill_merge(struct dir_context *ctx, const char *name,
int namelen, loff_t offset, u64 ino,
unsigned int d_type)
{
@@ -538,7 +538,7 @@ static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p)
goto out;
}

-static int ovl_fill_plain(struct dir_context *ctx, const char *name,
+static bool ovl_fill_plain(struct dir_context *ctx, const char *name,
int namelen, loff_t offset, u64 ino,
unsigned int d_type)
{
@@ -550,11 +550,11 @@ static int ovl_fill_plain(struct dir_context *ctx, const char *name,
p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type);
if (p == NULL) {
rdd->err = -ENOMEM;
- return -ENOMEM;
+ return false;
}
list_add_tail(&p->l_node, rdd->list);

- return 0;
+ return true;
}

static int ovl_dir_read_impure(struct path *path, struct list_head *list,
@@ -658,7 +658,7 @@ struct ovl_readdir_translate {
bool xinowarn;
};

-static int ovl_fill_real(struct dir_context *ctx, const char *name,
+static bool ovl_fill_real(struct dir_context *ctx, const char *name,
int namelen, loff_t offset, u64 ino,
unsigned int d_type)
{
@@ -1037,7 +1037,7 @@ void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list)
inode_unlock(upper->d_inode);
}

-static int ovl_check_d_type(struct dir_context *ctx, const char *name,
+static bool ovl_check_d_type(struct dir_context *ctx, const char *name,
int namelen, loff_t offset, u64 ino,
unsigned int d_type)
{
@@ -1046,12 +1046,12 @@ static int ovl_check_d_type(struct dir_context *ctx, const char *name,

/* Even if d_type is not supported, DT_DIR is returned for . and .. */
if (!strncmp(name, ".", namelen) || !strncmp(name, "..", namelen))
- return 0;
+ return true;

if (d_type != DT_UNKNOWN)
rdd->d_type_supported = true;

- return 0;
+ return true;
}

/*
diff --git a/fs/readdir.c b/fs/readdir.c
index 19434b3c982c..d5ef78273076 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -140,7 +140,7 @@ struct readdir_callback {
int result;
};

-static int fillonedir(struct dir_context *ctx, const char *name, int namlen,
+static bool fillonedir(struct dir_context *ctx, const char *name, int namlen,
loff_t offset, u64 ino, unsigned int d_type)
{
struct readdir_callback *buf =
@@ -149,11 +149,11 @@ static int fillonedir(struct dir_context *ctx, const char *name, int namlen,
unsigned long d_ino;

if (buf->result)
- return -EINVAL;
+ return false;
d_ino = ino;
if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
buf->result = -EOVERFLOW;
- return -EOVERFLOW;
+ return false;
}
buf->result++;
dirent = buf->dirent;
@@ -166,12 +166,12 @@ static int fillonedir(struct dir_context *ctx, const char *name, int namlen,
unsafe_put_user(namlen, &dirent->d_namlen, efault_end);
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
user_write_access_end();
- return 0;
+ return true;
efault_end:
user_write_access_end();
efault:
buf->result = -EFAULT;
- return -EFAULT;
+ return false;
}

SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
@@ -216,7 +216,7 @@ struct getdents_callback {
int error;
};

-static int filldir(struct dir_context *ctx, const char *name, int namlen,
+static bool filldir(struct dir_context *ctx, const char *name, int namlen,
loff_t offset, u64 ino, unsigned int d_type)
{
struct linux_dirent __user *dirent, *prev;
@@ -229,18 +229,18 @@ static int filldir(struct dir_context *ctx, const char *name, int namlen,

buf->error = verify_dirent_name(name, namlen);
if (unlikely(buf->error))
- return buf->error;
+ return false;
buf->error = -EINVAL; /* only used if we fail.. */
if (reclen > buf->count)
- return -EINVAL;
+ return false;
d_ino = ino;
if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
buf->error = -EOVERFLOW;
- return -EOVERFLOW;
+ return false;
}
prev_reclen = buf->prev_reclen;
if (prev_reclen && signal_pending(current))
- return -EINTR;
+ return false;
dirent = buf->current_dir;
prev = (void __user *) dirent - prev_reclen;
if (!user_write_access_begin(prev, reclen + prev_reclen))
@@ -257,12 +257,12 @@ static int filldir(struct dir_context *ctx, const char *name, int namlen,
buf->current_dir = (void __user *)dirent + reclen;
buf->prev_reclen = reclen;
buf->count -= reclen;
- return 0;
+ return true;
efault_end:
user_write_access_end();
efault:
buf->error = -EFAULT;
- return -EFAULT;
+ return false;
}

SYSCALL_DEFINE3(getdents, unsigned int, fd,
@@ -304,7 +304,7 @@ struct getdents_callback64 {
int error;
};

-static int filldir64(struct dir_context *ctx, const char *name, int namlen,
+static bool filldir64(struct dir_context *ctx, const char *name, int namlen,
loff_t offset, u64 ino, unsigned int d_type)
{
struct linux_dirent64 __user *dirent, *prev;
@@ -316,13 +316,13 @@ static int filldir64(struct dir_context *ctx, const char *name, int namlen,

buf->error = verify_dirent_name(name, namlen);
if (unlikely(buf->error))
- return buf->error;
+ return false;
buf->error = -EINVAL; /* only used if we fail.. */
if (reclen > buf->count)
- return -EINVAL;
+ return false;
prev_reclen = buf->prev_reclen;
if (prev_reclen && signal_pending(current))
- return -EINTR;
+ return false;
dirent = buf->current_dir;
prev = (void __user *)dirent - prev_reclen;
if (!user_write_access_begin(prev, reclen + prev_reclen))
@@ -339,13 +339,13 @@ static int filldir64(struct dir_context *ctx, const char *name, int namlen,
buf->prev_reclen = reclen;
buf->current_dir = (void __user *)dirent + reclen;
buf->count -= reclen;
- return 0;
+ return true;

efault_end:
user_write_access_end();
efault:
buf->error = -EFAULT;
- return -EFAULT;
+ return false;
}

SYSCALL_DEFINE3(getdents64, unsigned int, fd,
@@ -394,7 +394,7 @@ struct compat_readdir_callback {
int result;
};

-static int compat_fillonedir(struct dir_context *ctx, const char *name,
+static bool compat_fillonedir(struct dir_context *ctx, const char *name,
int namlen, loff_t offset, u64 ino,
unsigned int d_type)
{
@@ -404,11 +404,11 @@ static int compat_fillonedir(struct dir_context *ctx, const char *name,
compat_ulong_t d_ino;

if (buf->result)
- return -EINVAL;
+ return false;
d_ino = ino;
if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
buf->result = -EOVERFLOW;
- return -EOVERFLOW;
+ return false;
}
buf->result++;
dirent = buf->dirent;
@@ -421,12 +421,12 @@ static int compat_fillonedir(struct dir_context *ctx, const char *name,
unsafe_put_user(namlen, &dirent->d_namlen, efault_end);
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
user_write_access_end();
- return 0;
+ return true;
efault_end:
user_write_access_end();
efault:
buf->result = -EFAULT;
- return -EFAULT;
+ return false;
}

COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
@@ -465,7 +465,7 @@ struct compat_getdents_callback {
int error;
};

-static int compat_filldir(struct dir_context *ctx, const char *name, int namlen,
+static bool compat_filldir(struct dir_context *ctx, const char *name, int namlen,
loff_t offset, u64 ino, unsigned int d_type)
{
struct compat_linux_dirent __user *dirent, *prev;
@@ -478,18 +478,18 @@ static int compat_filldir(struct dir_context *ctx, const char *name, int namlen,

buf->error = verify_dirent_name(name, namlen);
if (unlikely(buf->error))
- return buf->error;
+ return false;
buf->error = -EINVAL; /* only used if we fail.. */
if (reclen > buf->count)
- return -EINVAL;
+ return false;
d_ino = ino;
if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
buf->error = -EOVERFLOW;
- return -EOVERFLOW;
+ return false;
}
prev_reclen = buf->prev_reclen;
if (prev_reclen && signal_pending(current))
- return -EINTR;
+ return false;
dirent = buf->current_dir;
prev = (void __user *) dirent - prev_reclen;
if (!user_write_access_begin(prev, reclen + prev_reclen))
@@ -505,12 +505,12 @@ static int compat_filldir(struct dir_context *ctx, const char *name, int namlen,
buf->prev_reclen = reclen;
buf->current_dir = (void __user *)dirent + reclen;
buf->count -= reclen;
- return 0;
+ return true;
efault_end:
user_write_access_end();
efault:
buf->error = -EFAULT;
- return -EFAULT;
+ return false;
}

COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index bd073836e141..70615594c19b 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -189,7 +189,7 @@ struct reiserfs_dentry_buf {
struct dentry *dentries[8];
};

-static int
+static bool
fill_with_dentries(struct dir_context *ctx, const char *name, int namelen,
loff_t offset, u64 ino, unsigned int d_type)
{
@@ -200,16 +200,16 @@ fill_with_dentries(struct dir_context *ctx, const char *name, int namelen,
WARN_ON_ONCE(!inode_is_locked(d_inode(dbuf->xadir)));

if (dbuf->count == ARRAY_SIZE(dbuf->dentries))
- return -ENOSPC;
+ return false;

if (name[0] == '.' && (namelen < 2 ||
(namelen == 2 && name[1] == '.')))
- return 0;
+ return true;

dentry = lookup_one_len(name, dbuf->xadir, namelen);
if (IS_ERR(dentry)) {
dbuf->err = PTR_ERR(dentry);
- return PTR_ERR(dentry);
+ return false;
} else if (d_really_is_negative(dentry)) {
/* A directory entry exists, but no file? */
reiserfs_error(dentry->d_sb, "xattr-20003",
@@ -218,11 +218,11 @@ fill_with_dentries(struct dir_context *ctx, const char *name, int namelen,
dentry, dbuf->xadir);
dput(dentry);
dbuf->err = -EIO;
- return -EIO;
+ return false;
}

dbuf->dentries[dbuf->count++] = dentry;
- return 0;
+ return true;
}

static void
@@ -804,7 +804,7 @@ struct listxattr_buf {
struct dentry *dentry;
};

-static int listxattr_filler(struct dir_context *ctx, const char *name,
+static bool listxattr_filler(struct dir_context *ctx, const char *name,
int namelen, loff_t offset, u64 ino,
unsigned int d_type)
{
@@ -820,19 +820,19 @@ static int listxattr_filler(struct dir_context *ctx, const char *name,
name);
if (!handler /* Unsupported xattr name */ ||
(handler->list && !handler->list(b->dentry)))
- return 0;
+ return true;
size = namelen + 1;
if (b->buf) {
if (b->pos + size > b->size) {
b->pos = -ERANGE;
- return -ERANGE;
+ return false;
}
memcpy(b->buf + b->pos, name, namelen);
b->buf[b->pos + namelen] = 0;
}
b->pos += size;
}
- return 0;
+ return true;
}

/*
diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
index 178b3455a170..10bbc9c4e7ec 100644
--- a/fs/xfs/scrub/dir.c
+++ b/fs/xfs/scrub/dir.c
@@ -100,7 +100,7 @@ xchk_dir_check_ftype(
* we check the inode number to make sure it's sane, then we check that
* we can look up this filename. Finally, we check the ftype.
*/
-STATIC int
+STATIC bool
xchk_dir_actor(
struct dir_context *dir_iter,
const char *name,
@@ -125,7 +125,7 @@ xchk_dir_actor(
xfs_dir2_dataptr_to_db(mp->m_dir_geo, pos));

if (xchk_should_terminate(sdc->sc, &error))
- return error;
+ return error == 0;

/* Does this inode number make sense? */
if (!xfs_verify_dir_ino(mp, ino)) {
@@ -192,8 +192,8 @@ xchk_dir_actor(
* and return zero to xchk_directory.
*/
if (error == 0 && sdc->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
- return -EFSCORRUPTED;
- return error;
+ return false;
+ return error == 0;
}

/* Scrub a directory btree record. */
diff --git a/fs/xfs/scrub/parent.c b/fs/xfs/scrub/parent.c
index 66c35f6dfc24..3b4a3ba23e68 100644
--- a/fs/xfs/scrub/parent.c
+++ b/fs/xfs/scrub/parent.c
@@ -39,7 +39,7 @@ struct xchk_parent_ctx {
};

/* Look for a single entry in a directory pointing to an inode. */
-STATIC int
+STATIC bool
xchk_parent_actor(
struct dir_context *dc,
const char *name,
@@ -63,7 +63,7 @@ xchk_parent_actor(
if (xchk_should_terminate(spc->sc, &error))
spc->cancelled = true;

- return error;
+ return error == 0;
}

/* Count the number of dentries in the parent dir that point to this inode. */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index ec8f3ddf4a6a..76073123964b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1836,7 +1836,7 @@ extern bool may_open_dev(const struct path *path);
* to have different dirent layouts depending on the binary type.
*/
struct dir_context;
-typedef int (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64,
+typedef bool (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64,
unsigned);

struct dir_context {
@@ -3518,17 +3518,17 @@ static inline bool dir_emit(struct dir_context *ctx,
const char *name, int namelen,
u64 ino, unsigned type)
{
- return ctx->actor(ctx, name, namelen, ctx->pos, ino, type) == 0;
+ return ctx->actor(ctx, name, namelen, ctx->pos, ino, type);
}
static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx)
{
return ctx->actor(ctx, ".", 1, ctx->pos,
- file->f_path.dentry->d_inode->i_ino, DT_DIR) == 0;
+ file->f_path.dentry->d_inode->i_ino, DT_DIR);
}
static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx)
{
return ctx->actor(ctx, "..", 2, ctx->pos,
- parent_ino(file->f_path.dentry), DT_DIR) == 0;
+ parent_ino(file->f_path.dentry), DT_DIR);
}
static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx)
{