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authorAl Viro <viro@zeniv.linux.org.uk>2016-05-04 21:04:13 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2016-05-04 21:04:13 +0300
commit6a480a7842545ec520a91730209ec0bae41694c1 (patch)
treeba40d93639c0cce7e461880199023d371f1b2535
parent10c64cea04d3c75c306b3f990586ffb343b63287 (diff)
downloadlinux-6a480a7842545ec520a91730209ec0bae41694c1.tar.xz
ecryptfs: fix handling of directory opening
First of all, trying to open them r/w is idiocy; it's guaranteed to fail. Moreover, assigning ->f_pos and assuming that everything will work is blatantly broken - try that with e.g. tmpfs as underlying layer and watch the fireworks. There may be a non-trivial amount of state associated with current IO position, well beyond the numeric offset. Using the single struct file associated with underlying inode is really not a good idea; we ought to open one for each ecryptfs directory struct file. Additionally, file_operations both for directories and non-directories are full of pointless methods; non-directories should *not* have ->iterate(), directories should not have ->flush(), ->fasync() and ->splice_read(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/ecryptfs/file.c71
1 files changed, 55 insertions, 16 deletions
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index feef8a9c4de7..f02404052b7b 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -112,7 +112,6 @@ static int ecryptfs_readdir(struct file *file, struct dir_context *ctx)
.sb = inode->i_sb,
};
lower_file = ecryptfs_file_to_lower(file);
- lower_file->f_pos = ctx->pos;
rc = iterate_dir(lower_file, &buf.ctx);
ctx->pos = buf.ctx.pos;
if (rc < 0)
@@ -223,14 +222,6 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
}
ecryptfs_set_file_lower(
file, ecryptfs_inode_to_private(inode)->lower_file);
- if (d_is_dir(ecryptfs_dentry)) {
- ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
- mutex_lock(&crypt_stat->cs_mutex);
- crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
- mutex_unlock(&crypt_stat->cs_mutex);
- rc = 0;
- goto out;
- }
rc = read_or_initialize_metadata(ecryptfs_dentry);
if (rc)
goto out_put;
@@ -247,6 +238,45 @@ out:
return rc;
}
+/**
+ * ecryptfs_dir_open
+ * @inode: inode speciying file to open
+ * @file: Structure to return filled in
+ *
+ * Opens the file specified by inode.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int ecryptfs_dir_open(struct inode *inode, struct file *file)
+{
+ struct dentry *ecryptfs_dentry = file->f_path.dentry;
+ /* Private value of ecryptfs_dentry allocated in
+ * ecryptfs_lookup() */
+ struct ecryptfs_file_info *file_info;
+ struct file *lower_file;
+
+ /* Released in ecryptfs_release or end of function if failure */
+ file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
+ ecryptfs_set_file_private(file, file_info);
+ if (unlikely(!file_info)) {
+ ecryptfs_printk(KERN_ERR,
+ "Error attempting to allocate memory\n");
+ return -ENOMEM;
+ }
+ lower_file = dentry_open(ecryptfs_dentry_to_lower_path(ecryptfs_dentry),
+ file->f_flags, current_cred());
+ if (IS_ERR(lower_file)) {
+ printk(KERN_ERR "%s: Error attempting to initialize "
+ "the lower file for the dentry with name "
+ "[%pd]; rc = [%ld]\n", __func__,
+ ecryptfs_dentry, PTR_ERR(lower_file));
+ kmem_cache_free(ecryptfs_file_info_cache, file_info);
+ return PTR_ERR(lower_file);
+ }
+ ecryptfs_set_file_lower(file, lower_file);
+ return 0;
+}
+
static int ecryptfs_flush(struct file *file, fl_owner_t td)
{
struct file *lower_file = ecryptfs_file_to_lower(file);
@@ -267,6 +297,19 @@ static int ecryptfs_release(struct inode *inode, struct file *file)
return 0;
}
+static int ecryptfs_dir_release(struct inode *inode, struct file *file)
+{
+ fput(ecryptfs_file_to_lower(file));
+ kmem_cache_free(ecryptfs_file_info_cache,
+ ecryptfs_file_to_private(file));
+ return 0;
+}
+
+static loff_t ecryptfs_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+ return vfs_llseek(ecryptfs_file_to_lower(file), offset, whence);
+}
+
static int
ecryptfs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
@@ -346,20 +389,16 @@ const struct file_operations ecryptfs_dir_fops = {
#ifdef CONFIG_COMPAT
.compat_ioctl = ecryptfs_compat_ioctl,
#endif
- .open = ecryptfs_open,
- .flush = ecryptfs_flush,
- .release = ecryptfs_release,
+ .open = ecryptfs_dir_open,
+ .release = ecryptfs_dir_release,
.fsync = ecryptfs_fsync,
- .fasync = ecryptfs_fasync,
- .splice_read = generic_file_splice_read,
- .llseek = default_llseek,
+ .llseek = ecryptfs_dir_llseek,
};
const struct file_operations ecryptfs_main_fops = {
.llseek = generic_file_llseek,
.read_iter = ecryptfs_read_update_atime,
.write_iter = generic_file_write_iter,
- .iterate = ecryptfs_readdir,
.unlocked_ioctl = ecryptfs_unlocked_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = ecryptfs_compat_ioctl,