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-rw-r--r--fs/exportfs/expfs.c1
-rw-r--r--fs/overlayfs/readdir.c12
-rw-r--r--fs/readdir.c29
-rw-r--r--include/linux/fs.h7
4 files changed, 33 insertions, 16 deletions
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 128dd092916b..48f0c505b50f 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -284,6 +284,7 @@ static int get_name(const struct path *path, char *name, struct dentry *child)
};
struct getdents_callback buffer = {
.ctx.actor = filldir_one,
+ .ctx.count = INT_MAX,
.name = name,
};
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 881ec5592da5..126c797751e9 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -351,6 +351,7 @@ static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list,
struct path realpath;
struct ovl_readdir_data rdd = {
.ctx.actor = ovl_fill_merge,
+ .ctx.count = INT_MAX,
.dentry = dentry,
.list = list,
.root = root,
@@ -571,6 +572,7 @@ static int ovl_dir_read_impure(const struct path *path, struct list_head *list,
struct ovl_cache_entry *p, *n;
struct ovl_readdir_data rdd = {
.ctx.actor = ovl_fill_plain,
+ .ctx.count = INT_MAX,
.list = list,
.root = root,
};
@@ -672,6 +674,7 @@ static bool ovl_fill_real(struct dir_context *ctx, const char *name,
struct ovl_readdir_translate *rdt =
container_of(ctx, struct ovl_readdir_translate, ctx);
struct dir_context *orig_ctx = rdt->orig_ctx;
+ bool res;
if (rdt->parent_ino && strcmp(name, "..") == 0) {
ino = rdt->parent_ino;
@@ -686,7 +689,10 @@ static bool ovl_fill_real(struct dir_context *ctx, const char *name,
name, namelen, rdt->xinowarn);
}
- return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type);
+ res = orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type);
+ ctx->count = orig_ctx->count;
+
+ return res;
}
static bool ovl_is_impure_dir(struct file *file)
@@ -713,6 +719,7 @@ static int ovl_iterate_real(struct file *file, struct dir_context *ctx)
const struct ovl_layer *lower_layer = ovl_layer_lower(dir);
struct ovl_readdir_translate rdt = {
.ctx.actor = ovl_fill_real,
+ .ctx.count = ctx->count,
.orig_ctx = ctx,
.xinobits = ovl_xino_bits(ofs),
.xinowarn = ovl_xino_warn(ofs),
@@ -1073,6 +1080,7 @@ int ovl_check_d_type_supported(const struct path *realpath)
int err;
struct ovl_readdir_data rdd = {
.ctx.actor = ovl_check_d_type,
+ .ctx.count = INT_MAX,
.d_type_supported = false,
};
@@ -1094,6 +1102,7 @@ static int ovl_workdir_cleanup_recurse(struct ovl_fs *ofs, const struct path *pa
struct ovl_cache_entry *p;
struct ovl_readdir_data rdd = {
.ctx.actor = ovl_fill_plain,
+ .ctx.count = INT_MAX,
.list = &list,
};
bool incompat = false;
@@ -1178,6 +1187,7 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs)
struct ovl_cache_entry *p;
struct ovl_readdir_data rdd = {
.ctx.actor = ovl_fill_plain,
+ .ctx.count = INT_MAX,
.list = &list,
};
diff --git a/fs/readdir.c b/fs/readdir.c
index 857d402bc531..7764b8638978 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -222,6 +222,7 @@ SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
CLASS(fd_pos, f)(fd);
struct readdir_callback buf = {
.ctx.actor = fillonedir,
+ .ctx.count = 1, /* Hint to fs: just one entry. */
.dirent = dirent
};
@@ -252,7 +253,6 @@ struct getdents_callback {
struct dir_context ctx;
struct linux_dirent __user * current_dir;
int prev_reclen;
- int count;
int error;
};
@@ -275,7 +275,7 @@ static bool filldir(struct dir_context *ctx, const char *name, int namlen,
if (unlikely(buf->error))
return false;
buf->error = -EINVAL; /* only used if we fail.. */
- if (reclen > buf->count)
+ if (reclen > ctx->count)
return false;
d_ino = ino;
if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
@@ -300,7 +300,7 @@ static bool filldir(struct dir_context *ctx, const char *name, int namlen,
buf->current_dir = (void __user *)dirent + reclen;
buf->prev_reclen = reclen;
- buf->count -= reclen;
+ ctx->count -= reclen;
return true;
efault_end:
user_write_access_end();
@@ -315,7 +315,7 @@ SYSCALL_DEFINE3(getdents, unsigned int, fd,
CLASS(fd_pos, f)(fd);
struct getdents_callback buf = {
.ctx.actor = filldir,
- .count = count,
+ .ctx.count = count,
.current_dir = dirent
};
int error;
@@ -333,7 +333,7 @@ SYSCALL_DEFINE3(getdents, unsigned int, fd,
if (put_user(buf.ctx.pos, &lastdirent->d_off))
error = -EFAULT;
else
- error = count - buf.count;
+ error = count - buf.ctx.count;
}
return error;
}
@@ -342,7 +342,6 @@ struct getdents_callback64 {
struct dir_context ctx;
struct linux_dirent64 __user * current_dir;
int prev_reclen;
- int count;
int error;
};
@@ -364,7 +363,7 @@ static bool filldir64(struct dir_context *ctx, const char *name, int namlen,
if (unlikely(buf->error))
return false;
buf->error = -EINVAL; /* only used if we fail.. */
- if (reclen > buf->count)
+ if (reclen > ctx->count)
return false;
prev_reclen = buf->prev_reclen;
if (!(flags & FILLDIR_FLAG_NOINTR) && prev_reclen && signal_pending(current))
@@ -384,7 +383,7 @@ static bool filldir64(struct dir_context *ctx, const char *name, int namlen,
buf->prev_reclen = reclen;
buf->current_dir = (void __user *)dirent + reclen;
- buf->count -= reclen;
+ ctx->count -= reclen;
return true;
efault_end:
@@ -400,7 +399,7 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd,
CLASS(fd_pos, f)(fd);
struct getdents_callback64 buf = {
.ctx.actor = filldir64,
- .count = count,
+ .ctx.count = count,
.current_dir = dirent
};
int error;
@@ -419,7 +418,7 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd,
if (put_user(d_off, &lastdirent->d_off))
error = -EFAULT;
else
- error = count - buf.count;
+ error = count - buf.ctx.count;
}
return error;
}
@@ -483,6 +482,7 @@ COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
CLASS(fd_pos, f)(fd);
struct compat_readdir_callback buf = {
.ctx.actor = compat_fillonedir,
+ .ctx.count = 1, /* Hint to fs: just one entry. */
.dirent = dirent
};
@@ -507,7 +507,6 @@ struct compat_getdents_callback {
struct dir_context ctx;
struct compat_linux_dirent __user *current_dir;
int prev_reclen;
- int count;
int error;
};
@@ -530,7 +529,7 @@ static bool compat_filldir(struct dir_context *ctx, const char *name, int namlen
if (unlikely(buf->error))
return false;
buf->error = -EINVAL; /* only used if we fail.. */
- if (reclen > buf->count)
+ if (reclen > ctx->count)
return false;
d_ino = ino;
if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
@@ -554,7 +553,7 @@ static bool 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;
+ ctx->count -= reclen;
return true;
efault_end:
user_write_access_end();
@@ -569,8 +568,8 @@ COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
CLASS(fd_pos, f)(fd);
struct compat_getdents_callback buf = {
.ctx.actor = compat_filldir,
+ .ctx.count = count,
.current_dir = dirent,
- .count = count
};
int error;
@@ -587,7 +586,7 @@ COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
if (put_user(buf.ctx.pos, &lastdirent->d_off))
error = -EFAULT;
else
- error = count - buf.count;
+ error = count - buf.ctx.count;
}
return error;
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c8b5af17060e..ddd54a664916 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2071,6 +2071,13 @@ typedef bool (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64,
struct dir_context {
filldir_t actor;
loff_t pos;
+ /*
+ * Filesystems MUST NOT MODIFY count, but may use as a hint:
+ * 0 unknown
+ * > 0 space in buffer (assume at least one entry)
+ * INT_MAX unlimited
+ */
+ int count;
};
/* If OR-ed with d_type, pending signals are not checked */
generated by cgit v1.2.3 (git 2.46.0) at 2025-07-25 17:27:09 +0000