summaryrefslogtreecommitdiff
path: root/fs/ubifs
diff options
context:
space:
mode:
authorChristian Brauner <brauner@kernel.org>2024-08-30 15:04:58 +0200
committerChristian Brauner <brauner@kernel.org>2024-09-12 11:58:45 +0200
commit1146e5a69efca76501378f748388fd7742ad09cf (patch)
tree34641783429b07ac30c91722bcb8cf2be4e22e99 /fs/ubifs
parent0bea8287df6c86cacaf34eef167f23dcc5dbcede (diff)
ubifs: store cookie in private data
Store the cookie to detect concurrent seeks on directories in file->private_data. Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-17-6d3e4816aa7b@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/ubifs')
-rw-r--r--fs/ubifs/dir.c64
1 files changed, 46 insertions, 18 deletions
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index c77ea57fe696..fda82f3e16e8 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -555,6 +555,11 @@ static unsigned int vfs_dent_type(uint8_t type)
return 0;
}
+struct ubifs_dir_data {
+ struct ubifs_dent_node *dent;
+ u64 cookie;
+};
+
/*
* The classical Unix view for directory is that it is a linear array of
* (name, inode number) entries. Linux/VFS assumes this model as well.
@@ -582,6 +587,7 @@ static int ubifs_readdir(struct file *file, struct dir_context *ctx)
struct inode *dir = file_inode(file);
struct ubifs_info *c = dir->i_sb->s_fs_info;
bool encrypted = IS_ENCRYPTED(dir);
+ struct ubifs_dir_data *data = file->private_data;
dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, ctx->pos);
@@ -604,27 +610,27 @@ static int ubifs_readdir(struct file *file, struct dir_context *ctx)
fstr_real_len = fstr.len;
}
- if (file->f_version == 0) {
+ if (data->cookie == 0) {
/*
- * The file was seek'ed, which means that @file->private_data
+ * The file was seek'ed, which means that @data->dent
* is now invalid. This may also be just the first
* 'ubifs_readdir()' invocation, in which case
- * @file->private_data is NULL, and the below code is
+ * @data->dent is NULL, and the below code is
* basically a no-op.
*/
- kfree(file->private_data);
- file->private_data = NULL;
+ kfree(data->dent);
+ data->dent = NULL;
}
/*
- * 'generic_file_llseek()' unconditionally sets @file->f_version to
- * zero, and we use this for detecting whether the file was seek'ed.
+ * 'ubifs_dir_llseek()' sets @data->cookie to zero, and we use this
+ * for detecting whether the file was seek'ed.
*/
- file->f_version = 1;
+ data->cookie = 1;
/* File positions 0 and 1 correspond to "." and ".." */
if (ctx->pos < 2) {
- ubifs_assert(c, !file->private_data);
+ ubifs_assert(c, !data->dent);
if (!dir_emit_dots(file, ctx)) {
if (encrypted)
fscrypt_fname_free_buffer(&fstr);
@@ -641,10 +647,10 @@ static int ubifs_readdir(struct file *file, struct dir_context *ctx)
}
ctx->pos = key_hash_flash(c, &dent->key);
- file->private_data = dent;
+ data->dent = dent;
}
- dent = file->private_data;
+ dent = data->dent;
if (!dent) {
/*
* The directory was seek'ed to and is now readdir'ed.
@@ -658,7 +664,7 @@ static int ubifs_readdir(struct file *file, struct dir_context *ctx)
goto out;
}
ctx->pos = key_hash_flash(c, &dent->key);
- file->private_data = dent;
+ data->dent = dent;
}
while (1) {
@@ -701,15 +707,15 @@ static int ubifs_readdir(struct file *file, struct dir_context *ctx)
goto out;
}
- kfree(file->private_data);
+ kfree(data->dent);
ctx->pos = key_hash_flash(c, &dent->key);
- file->private_data = dent;
+ data->dent = dent;
cond_resched();
}
out:
- kfree(file->private_data);
- file->private_data = NULL;
+ kfree(data->dent);
+ data->dent = NULL;
if (encrypted)
fscrypt_fname_free_buffer(&fstr);
@@ -733,7 +739,10 @@ out:
/* Free saved readdir() state when the directory is closed */
static int ubifs_dir_release(struct inode *dir, struct file *file)
{
- kfree(file->private_data);
+ struct ubifs_dir_data *data = file->private_data;
+
+ kfree(data->dent);
+ kfree(data);
file->private_data = NULL;
return 0;
}
@@ -1712,6 +1721,24 @@ int ubifs_getattr(struct mnt_idmap *idmap, const struct path *path,
return 0;
}
+static int ubifs_dir_open(struct inode *inode, struct file *file)
+{
+ struct ubifs_dir_data *data;
+
+ data = kzalloc(sizeof(struct ubifs_dir_data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ file->private_data = data;
+ return 0;
+}
+
+static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+ struct ubifs_dir_data *data = file->private_data;
+
+ return generic_llseek_cookie(file, offset, whence, &data->cookie);
+}
+
const struct inode_operations ubifs_dir_inode_operations = {
.lookup = ubifs_lookup,
.create = ubifs_create,
@@ -1732,7 +1759,8 @@ const struct inode_operations ubifs_dir_inode_operations = {
};
const struct file_operations ubifs_dir_operations = {
- .llseek = generic_file_llseek,
+ .open = ubifs_dir_open,
+ .llseek = ubifs_dir_llseek,
.release = ubifs_dir_release,
.read = generic_read_dir,
.iterate_shared = ubifs_readdir,