When getting the directory contents, the entries are fist fetched to a
kernel buffer, then they are copied to userspace with dir_emit(). This
second phase is non-blocking as long as the userspace buffer is not paged
out, making it interruptible makes zero sense.
Overload d_type as flags, since it only uses 4 bits from 32.
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
fs/fuse/readdir.c | 4 ++--
fs/readdir.c | 15 ++++++++++++---
include/linux/fs.h | 3 +++
3 files changed, 17 insertions(+), 5 deletions(-)
diff --git a/fs/fuse/readdir.c b/fs/fuse/readdir.c
index 17ce9636a2b1..edcd6f18a8a8 100644
--- a/fs/fuse/readdir.c
+++ b/fs/fuse/readdir.c
@@ -120,7 +120,7 @@ static bool fuse_emit(struct file *file, struct dir_context *ctx,
fuse_add_dirent_to_cache(file, dirent, ctx->pos);
return dir_emit(ctx, dirent->name, dirent->namelen, dirent->ino,
- dirent->type);
+ dirent->type | FILLDIR_FLAG_NOINTR);
}
static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
@@ -419,7 +419,7 @@ static enum fuse_parse_result fuse_parse_cache(struct fuse_file *ff,
if (ff->readdir.pos == ctx->pos) {
res = FOUND_SOME;
if (!dir_emit(ctx, dirent->name, dirent->namelen,
- dirent->ino, dirent->type))
+ dirent->ino, dirent->type | FILLDIR_FLAG_NOINTR))
return FOUND_ALL;
ctx->pos = dirent->off;
}
diff --git a/fs/readdir.c b/fs/readdir.c
index 0038efda417b..00ceae3fc2e3 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -266,6 +266,9 @@ static bool filldir(struct dir_context *ctx, const char *name, int namlen,
int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
sizeof(long));
int prev_reclen;
+ unsigned int flags = d_type;
+
+ d_type &= S_DT_MASK;
buf->error = verify_dirent_name(name, namlen);
if (unlikely(buf->error))
@@ -279,7 +282,7 @@ static bool filldir(struct dir_context *ctx, const char *name, int namlen,
return false;
}
prev_reclen = buf->prev_reclen;
- if (prev_reclen && signal_pending(current))
+ if (!(flags & FILLDIR_FLAG_NOINTR) && prev_reclen && signal_pending(current))
return false;
dirent = buf->current_dir;
prev = (void __user *) dirent - prev_reclen;
@@ -351,6 +354,9 @@ static bool filldir64(struct dir_context *ctx, const char *name, int namlen,
int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
sizeof(u64));
int prev_reclen;
+ unsigned int flags = d_type;
+
+ d_type &= S_DT_MASK;
buf->error = verify_dirent_name(name, namlen);
if (unlikely(buf->error))
@@ -359,7 +365,7 @@ static bool filldir64(struct dir_context *ctx, const char *name, int namlen,
if (reclen > buf->count)
return false;
prev_reclen = buf->prev_reclen;
- if (prev_reclen && signal_pending(current))
+ if (!(flags & FILLDIR_FLAG_NOINTR) && prev_reclen && signal_pending(current))
return false;
dirent = buf->current_dir;
prev = (void __user *)dirent - prev_reclen;
@@ -513,6 +519,9 @@ static bool compat_filldir(struct dir_context *ctx, const char *name, int namlen
int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) +
namlen + 2, sizeof(compat_long_t));
int prev_reclen;
+ unsigned int flags = d_type;
+
+ d_type &= S_DT_MASK;
buf->error = verify_dirent_name(name, namlen);
if (unlikely(buf->error))
@@ -526,7 +535,7 @@ static bool compat_filldir(struct dir_context *ctx, const char *name, int namlen
return false;
}
prev_reclen = buf->prev_reclen;
- if (prev_reclen && signal_pending(current))
+ if (!(flags & FILLDIR_FLAG_NOINTR) && prev_reclen && signal_pending(current))
return false;
dirent = buf->current_dir;
prev = (void __user *) dirent - prev_reclen;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 016b0fe1536e..0f2a1a572e3a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2073,6 +2073,9 @@ struct dir_context {
loff_t pos;
};
+/* If OR-ed with d_type, pending signals are not checked */
+#define FILLDIR_FLAG_NOINTR 0x1000
+
/*
* These flags let !MMU mmap() govern direct device mapping vs immediate
* copying more easily for MAP_PRIVATE, especially for ROM filesystems.
--
2.49.0
