ext4: don't calculate total xattr header size unless needed

The function ext4_expand_extra_isize_ea() doesn't need the size of all
of the extended attribute headers.  So if we don't calculate it when
it is unneeded, it we can skip some undeeded memory references, and as
a bonus, we eliminate some kvetching by static code analysis tools.

Addresses-Coverity-Id: #741291

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Theodore Ts'o 2014-02-19 20:15:21 -05:00
parent 9a6633b1a3
commit 7b1b2c1b9c

View File

@ -567,12 +567,13 @@ static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
size_t *min_offs, void *base, int *total)
{
for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
*total += EXT4_XATTR_LEN(last->e_name_len);
if (!last->e_value_block && last->e_value_size) {
size_t offs = le16_to_cpu(last->e_value_offs);
if (offs < *min_offs)
*min_offs = offs;
}
if (total)
*total += EXT4_XATTR_LEN(last->e_name_len);
}
return (*min_offs - ((void *)last - base) - sizeof(__u32));
}
@ -1228,7 +1229,7 @@ int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
struct ext4_xattr_block_find *bs = NULL;
char *buffer = NULL, *b_entry_name = NULL;
size_t min_offs, free;
int total_ino, total_blk;
int total_ino;
void *base, *start, *end;
int extra_isize = 0, error = 0, tried_min_extra_isize = 0;
int s_min_extra_isize = le16_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize);
@ -1286,8 +1287,7 @@ int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
first = BFIRST(bh);
end = bh->b_data + bh->b_size;
min_offs = end - base;
free = ext4_xattr_free_space(first, &min_offs, base,
&total_blk);
free = ext4_xattr_free_space(first, &min_offs, base, NULL);
if (free < new_extra_isize) {
if (!tried_min_extra_isize && s_min_extra_isize) {
tried_min_extra_isize++;