Commit 57c1df07 authored by Zhang Yi's avatar Zhang Yi Committed by Theodore Ts'o
Browse files

ext4: refactor mext_check_arguments() 



When moving extents, mext_check_validity() performs some basic file
system and file checks. However, some essential checks need to be
performed after acquiring the i_rwsem are still scattered in
mext_check_arguments(). Move those checks into mext_check_validity() and
make it executes entirely under the i_rwsem to make the checks clearer.
Furthermore, rename mext_check_arguments() to mext_check_adjust_range(),
as it only performs checks and length adjustments on the move extent
range. Finally, also change the print message for the non-existent file
check to be consistent with other unsupported checks.

Signed-off-by: default avatarZhang Yi <yi.zhang@huawei.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Message-ID: <20251013015128.499308-8-yi.zhang@huaweicloud.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 22218516

fs/ext4/move_extent.c

+43 −54
Original line number Diff line number Diff line
@@ -501,38 +501,25 @@ static int mext_check_validity(struct inode *orig_inode, 
		return -EOPNOTSUPP;

	}



	return 0;

	/* Ext4 move extent supports only extent based file */

	if (!(ext4_test_inode_flag(orig_inode, EXT4_INODE_EXTENTS)) ||

	    !(ext4_test_inode_flag(donor_inode, EXT4_INODE_EXTENTS))) {

		ext4_msg(sb, KERN_ERR,

			 "Online defrag not supported for non-extent files");

		return -EOPNOTSUPP;

	}



/**

 * mext_check_arguments - Check whether move extent can be done

 *

 * @orig_inode:		original inode

 * @donor_inode:	donor inode

 * @orig_start:		logical start offset in block for orig

 * @donor_start:	logical start offset in block for donor

 * @len:		the number of blocks to be moved

 *

 * Check the arguments of ext4_move_extents() whether the files can be

 * exchanged with each other.

 * Return 0 on success, or a negative error value on failure.

 */

static int

mext_check_arguments(struct inode *orig_inode,

		     struct inode *donor_inode, __u64 orig_start,

		     __u64 donor_start, __u64 *len)

{

	__u64 orig_eof, donor_eof;



	if (donor_inode->i_mode & (S_ISUID|S_ISGID)) {

		ext4_debug("ext4 move extent: suid or sgid is set"

			   " to donor file [ino:orig %lu, donor %lu]\n",

		ext4_debug("ext4 move extent: suid or sgid is set to donor file [ino:orig %lu, donor %lu]\n",

			   orig_inode->i_ino, donor_inode->i_ino);

		return -EINVAL;

	}



	if (IS_IMMUTABLE(donor_inode) || IS_APPEND(donor_inode))

	if (IS_IMMUTABLE(donor_inode) || IS_APPEND(donor_inode)) {

		ext4_debug("ext4 move extent: donor should not be immutable or append file [ino:orig %lu, donor %lu]\n",

			   orig_inode->i_ino, donor_inode->i_ino);

		return -EPERM;

	}



	/* Ext4 move extent does not support swap files */

	if (IS_SWAPFILE(orig_inode) || IS_SWAPFILE(donor_inode)) {
@@ -547,27 +534,29 @@ mext_check_arguments(struct inode *orig_inode, 
		return -EOPNOTSUPP;

	}



	/* Ext4 move extent supports only extent based file */

	if (!(ext4_test_inode_flag(orig_inode, EXT4_INODE_EXTENTS))) {

		ext4_debug("ext4 move extent: orig file is not extents "

			"based file [ino:orig %lu]\n", orig_inode->i_ino);

		return -EOPNOTSUPP;

	} else if (!(ext4_test_inode_flag(donor_inode, EXT4_INODE_EXTENTS))) {

		ext4_debug("ext4 move extent: donor file is not extents "

			"based file [ino:donor %lu]\n", donor_inode->i_ino);

		return -EOPNOTSUPP;

	}



	if ((!orig_inode->i_size) || (!donor_inode->i_size)) {

		ext4_debug("ext4 move extent: File size is 0 byte\n");

		return -EINVAL;

	}



	return 0;

}



/*

 * Check the moving range of ext4_move_extents() whether the files can be

 * exchanged with each other, and adjust the length to fit within the file

 * size. Return 0 on success, or a negative error value on failure.

 */

static int mext_check_adjust_range(struct inode *orig_inode,

				   struct inode *donor_inode, __u64 orig_start,

				   __u64 donor_start, __u64 *len)

{

	__u64 orig_eof, donor_eof;



	/* Start offset should be same */

	if ((orig_start & ~(PAGE_MASK >> orig_inode->i_blkbits)) !=

	    (donor_start & ~(PAGE_MASK >> orig_inode->i_blkbits))) {

		ext4_debug("ext4 move extent: orig and donor's start "

			"offsets are not aligned [ino:orig %lu, donor %lu]\n",

		ext4_debug("ext4 move extent: orig and donor's start offsets are not aligned [ino:orig %lu, donor %lu]\n",

			   orig_inode->i_ino, donor_inode->i_ino);

		return -EINVAL;

	}
@@ -577,8 +566,8 @@ mext_check_arguments(struct inode *orig_inode, 
	    (*len > EXT_MAX_BLOCKS) ||

	    (donor_start + *len >= EXT_MAX_BLOCKS) ||

	    (orig_start + *len >= EXT_MAX_BLOCKS))  {

		ext4_debug("ext4 move extent: Can't handle over [%u] blocks "

			"[ino:orig %lu, donor %lu]\n", EXT_MAX_BLOCKS,

		ext4_debug("ext4 move extent: Can't handle over [%u] blocks [ino:orig %lu, donor %lu]\n",

			   EXT_MAX_BLOCKS,

			   orig_inode->i_ino, donor_inode->i_ino);

		return -EINVAL;

	}
@@ -594,9 +583,8 @@ mext_check_arguments(struct inode *orig_inode, 
	else if (donor_eof < donor_start + *len - 1)

		*len = donor_eof - donor_start;

	if (!*len) {

		ext4_debug("ext4 move extent: len should not be 0 "

			"[ino:orig %lu, donor %lu]\n", orig_inode->i_ino,

			donor_inode->i_ino);

		ext4_debug("ext4 move extent: len should not be 0 [ino:orig %lu, donor %lu]\n",

			   orig_inode->i_ino, donor_inode->i_ino);

		return -EINVAL;

	}
@@ -629,21 +617,21 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk, 
	ext4_lblk_t d_start = donor_blk;

	int ret;



	ret = mext_check_validity(orig_inode, donor_inode);

	if (ret)

		return ret;



	/* Protect orig and donor inodes against a truncate */

	lock_two_nondirectories(orig_inode, donor_inode);



	ret = mext_check_validity(orig_inode, donor_inode);

	if (ret)

		goto unlock;



	/* Wait for all existing dio workers */

	inode_dio_wait(orig_inode);

	inode_dio_wait(donor_inode);



	/* Protect extent tree against block allocations via delalloc */

	ext4_double_down_write_data_sem(orig_inode, donor_inode);

	/* Check the filesystem environment whether move_extent can be done */

	ret = mext_check_arguments(orig_inode, donor_inode, orig_blk,

	/* Check and adjust the specified move_extent range. */

	ret = mext_check_adjust_range(orig_inode, donor_inode, orig_blk,

				      donor_blk, &len);

	if (ret)

		goto out;
@@ -725,6 +713,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk, 


	ext4_free_ext_path(path);

	ext4_double_up_write_data_sem(orig_inode, donor_inode);

unlock:

	unlock_two_nondirectories(orig_inode, donor_inode);



	return ret;