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Commit 28688d32 authored by Paul Lawrence's avatar Paul Lawrence
Browse files

ANDROID: Incremental fs: Set credentials before reading/writing 



Bug: 174692664
Test: incfs_test passes, incremental installs work with ag/13082306
Signed-off-by: default avatarPaul Lawrence <paullawrence@google.com>

Change-Id: Ib1c924bbaff759f58f7d83bad8e23d7224ba7ed9
parent 152fd8f0

fs/incfs/data_mgmt.c

+14 −15
Original line number Diff line number Diff line
@@ -144,7 +144,7 @@ struct data_file *incfs_open_data_file(struct mount_info *mi, struct file *bf) 
	if (!S_ISREG(bf->f_inode->i_mode))

		return ERR_PTR(-EBADF);



	bfc = incfs_alloc_bfc(bf);

	bfc = incfs_alloc_bfc(mi, bf);

	if (IS_ERR(bfc))

		return ERR_CAST(bfc);
@@ -388,8 +388,8 @@ static void log_block_read(struct mount_info *mi, incfs_uuid_t *id, 
	schedule_delayed_work(&log->ml_wakeup_work, msecs_to_jiffies(16));

}



static int validate_hash_tree(struct file *bf, struct file *f, int block_index,

			      struct mem_range data, u8 *buf)

static int validate_hash_tree(struct backing_file_context *bfc, struct file *f,

			      int block_index, struct mem_range data, u8 *buf)

{

	struct data_file *df = get_incfs_data_file(f);

	u8 stored_digest[INCFS_MAX_HASH_SIZE] = {};
@@ -446,7 +446,7 @@ static int validate_hash_tree(struct file *bf, struct file *f, int block_index, 
		if (page)

			put_page(page);



		res = incfs_kread(bf, buf, INCFS_DATA_FILE_BLOCK_SIZE,

		res = incfs_kread(bfc, buf, INCFS_DATA_FILE_BLOCK_SIZE,

				  hash_block_offset[lvl] + sig->hash_offset);

		if (res < 0)

			return res;
@@ -919,7 +919,7 @@ ssize_t incfs_read_data_file_block(struct mem_range dst, struct file *f, 
	ssize_t result;

	size_t bytes_to_read;

	struct mount_info *mi = NULL;

	struct file *bf = NULL;

	struct backing_file_context *bfc = NULL;

	struct data_file_block block = {};

	struct data_file *df = get_incfs_data_file(f);
@@ -930,7 +930,7 @@ ssize_t incfs_read_data_file_block(struct mem_range dst, struct file *f, 
		return -ERANGE;



	mi = df->df_mount_info;

	bf = df->df_backing_file_context->bc_file;

	bfc = df->df_backing_file_context;



	result = wait_for_data_block(df, index, timeout_ms, &block);

	if (result < 0)
@@ -939,20 +939,20 @@ ssize_t incfs_read_data_file_block(struct mem_range dst, struct file *f, 
	pos = block.db_backing_file_data_offset;

	if (block.db_comp_alg == COMPRESSION_NONE) {

		bytes_to_read = min(dst.len, block.db_stored_size);

		result = incfs_kread(bf, dst.data, bytes_to_read, pos);

		result = incfs_kread(bfc, dst.data, bytes_to_read, pos);



		/* Some data was read, but not enough */

		if (result >= 0 && result != bytes_to_read)

			result = -EIO;

	} else {

		bytes_to_read = min(tmp.len, block.db_stored_size);

		result = incfs_kread(bf, tmp.data, bytes_to_read, pos);

		result = incfs_kread(bfc, tmp.data, bytes_to_read, pos);

		if (result == bytes_to_read) {

			result =

				decompress(range(tmp.data, bytes_to_read), dst);

			if (result < 0) {

				const char *name =

					bf->f_path.dentry->d_name.name;

				    bfc->bc_file->f_path.dentry->d_name.name;



				pr_warn_once("incfs: Decompression error. %s",

					     name);
@@ -964,7 +964,7 @@ ssize_t incfs_read_data_file_block(struct mem_range dst, struct file *f, 
	}



	if (result > 0) {

		int err = validate_hash_tree(bf, f, index, dst, tmp.data);

		int err = validate_hash_tree(bfc, f, index, dst, tmp.data);



		if (err < 0)

			result = err;
@@ -1027,14 +1027,13 @@ int incfs_process_new_data_block(struct data_file *df, 
unlock:

	mutex_unlock(&segment->blockmap_mutex);

	if (error)

		pr_debug("incfs: %s %d error: %d\n", __func__,

				block->block_index, error);

		pr_debug("%d error: %d\n", block->block_index, error);

	return error;

}



int incfs_read_file_signature(struct data_file *df, struct mem_range dst)

{

	struct file *bf = df->df_backing_file_context->bc_file;

	struct backing_file_context *bfc = df->df_backing_file_context;

	struct incfs_df_signature *sig;

	int read_res = 0;
@@ -1048,7 +1047,7 @@ int incfs_read_file_signature(struct data_file *df, struct mem_range dst) 
	if (dst.len < sig->sig_size)

		return -E2BIG;



	read_res = incfs_kread(bf, dst.data, sig->sig_size, sig->sig_offset);

	read_res = incfs_kread(bfc, dst.data, sig->sig_size, sig->sig_offset);



	if (read_res < 0)

		return read_res;
@@ -1174,7 +1173,7 @@ static int process_file_signature_md(struct incfs_file_signature *sg, 
		goto out;

	}



	read = incfs_kread(df->df_backing_file_context->bc_file, buf,

	read = incfs_kread(df->df_backing_file_context, buf,

			   signature->sig_size, signature->sig_offset);

	if (read < 0) {

		error = read;

fs/incfs/format.c

+22 −11
Original line number Diff line number Diff line
@@ -15,7 +15,8 @@ 
#include "format.h"

#include "data_mgmt.h"



struct backing_file_context *incfs_alloc_bfc(struct file *backing_file)

struct backing_file_context *incfs_alloc_bfc(struct mount_info *mi,

					     struct file *backing_file)

{

	struct backing_file_context *result = NULL;
@@ -24,6 +25,7 @@ struct backing_file_context *incfs_alloc_bfc(struct file *backing_file) 
		return ERR_PTR(-ENOMEM);



	result->bc_file = get_file(backing_file);

	result->bc_cred = mi->mi_owner;

	mutex_init(&result->bc_mutex);

	return result;

}
@@ -116,7 +118,7 @@ static int append_zeros(struct backing_file_context *bfc, size_t len) 
static int write_to_bf(struct backing_file_context *bfc, const void *buf,

			size_t count, loff_t pos)

{

	ssize_t res = incfs_kwrite(bfc->bc_file, buf, count, pos);

	ssize_t res = incfs_kwrite(bfc, buf, count, pos);



	if (res < 0)

		return res;
@@ -531,8 +533,7 @@ int incfs_read_blockmap_entries(struct backing_file_context *bfc, 
	if (start_index < 0 || bm_base_off <= 0)

		return -ENODATA;



	result = incfs_kread(bfc->bc_file, entries, bytes_to_read,

			     bm_entry_off);

	result = incfs_kread(bfc, entries, bytes_to_read, bm_entry_off);

	if (result < 0)

		return result;

	return result / sizeof(*entries);
@@ -549,7 +550,7 @@ int incfs_read_file_header(struct backing_file_context *bfc, 
		return -EFAULT;



	LOCK_REQUIRED(bfc->bc_mutex);

	bytes_read = incfs_kread(bfc->bc_file, &fh, sizeof(fh), 0);

	bytes_read = incfs_kread(bfc, &fh, sizeof(fh), 0);

	if (bytes_read < 0)

		return bytes_read;
@@ -603,8 +604,8 @@ int incfs_read_next_metadata_record(struct backing_file_context *bfc, 
		return -EPERM;



	memset(&handler->md_buffer, 0, max_md_size);

	bytes_read = incfs_kread(bfc->bc_file, &handler->md_buffer,

				 max_md_size, handler->md_record_offset);

	bytes_read = incfs_kread(bfc, &handler->md_buffer, max_md_size,

				 handler->md_record_offset);

	if (bytes_read < 0)

		return bytes_read;

	if (bytes_read < sizeof(*md_hdr))
@@ -680,12 +681,22 @@ int incfs_read_next_metadata_record(struct backing_file_context *bfc, 
	return res;

}



ssize_t incfs_kread(struct file *f, void *buf, size_t size, loff_t pos)

ssize_t incfs_kread(struct backing_file_context *bfc, void *buf, size_t size,

		    loff_t pos)

{

	return kernel_read(f, buf, size, &pos);

	const struct cred *old_cred = override_creds(bfc->bc_cred);

	int ret = kernel_read(bfc->bc_file, buf, size, &pos);



	revert_creds(old_cred);

	return ret;

}



ssize_t incfs_kwrite(struct file *f, const void *buf, size_t size, loff_t pos)

ssize_t incfs_kwrite(struct backing_file_context *bfc, const void *buf,

		     size_t size, loff_t pos)

{

	return kernel_write(f, buf, size, &pos);

	const struct cred *old_cred = override_creds(bfc->bc_cred);

	int ret = kernel_write(bfc->bc_file, buf, size, &pos);



	revert_creds(old_cred);

	return ret;

}

fs/incfs/format.h

+14 −3
Original line number Diff line number Diff line
@@ -256,6 +256,13 @@ struct backing_file_context { 
	 * 0 means there are no metadata records.

	 */

	loff_t bc_last_md_record_offset;



	/*

	 * Credentials to set before reads/writes

	 * Note that this is a pointer to the mount_info mi_owner field so

	 * there is no need to get/put the creds

	 */

	const struct cred *bc_cred;

};



struct metadata_handler {
@@ -283,7 +290,9 @@ struct metadata_handler { 
loff_t incfs_get_end_offset(struct file *f);



/* Backing file context management */

struct backing_file_context *incfs_alloc_bfc(struct file *backing_file);

struct mount_info;

struct backing_file_context *incfs_alloc_bfc(struct mount_info *mi,

					     struct file *backing_file);



void incfs_free_bfc(struct backing_file_context *bfc);
@@ -334,7 +343,9 @@ int incfs_read_blockmap_entries(struct backing_file_context *bfc, 
int incfs_read_next_metadata_record(struct backing_file_context *bfc,

				    struct metadata_handler *handler);



ssize_t incfs_kread(struct file *f, void *buf, size_t size, loff_t pos);

ssize_t incfs_kwrite(struct file *f, const void *buf, size_t size, loff_t pos);

ssize_t incfs_kread(struct backing_file_context *bfc, void *buf, size_t size,

		    loff_t pos);

ssize_t incfs_kwrite(struct backing_file_context *bfc, const void *buf,

		     size_t size, loff_t pos);



#endif /* _INCFS_FORMAT_H */

fs/incfs/vfs.c

+1 −1
Original line number Diff line number Diff line
@@ -905,7 +905,7 @@ static int init_new_file(struct mount_info *mi, struct dentry *dentry, 
		goto out;

	}



	bfc = incfs_alloc_bfc(new_file);

	bfc = incfs_alloc_bfc(mi, new_file);

	fput(new_file);

	if (IS_ERR(bfc)) {

		error = PTR_ERR(bfc);