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ocfs2: Wrap calculation of name+value pair size.
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An ocfs2 xattr entry stores the text name and value as a pair in the
storage area.  Obviously names and values can be variable-sized.  If a
value is too large for the entry storage, a tree root is stored instead.
The name+value pair is also padded.

Because of this, there are a million places in the code that do:

	if (needs_external_tree(value_size)
		namevalue_size = pad(name_size) + tree_root_size;
	else
		namevalue_size = pad(name_size) + pad(value_size);

Let's create some convenience functions to make the code more readable.
There are three forms.  The first takes the raw sizes.  The second takes
an ocfs2_xattr_info structure.  The third takes an existing
ocfs2_xattr_entry.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
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Joel Becker committed Feb 26, 2010
1 parent 18853b9 commit 199799a
Showing 1 changed file with 65 additions and 105 deletions.
170 changes: 65 additions & 105 deletions fs/ocfs2/xattr.c
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Original file line number Diff line number Diff line change
Expand Up @@ -183,6 +183,33 @@ struct ocfs2_xa_loc {
const struct ocfs2_xa_loc_operations *xl_ops;
};

/*
* Convenience functions to calculate how much space is needed for a
* given name+value pair
*/
static int namevalue_size(int name_len, uint64_t value_len)
{
if (value_len > OCFS2_XATTR_INLINE_SIZE)
return OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_ROOT_SIZE;
else
return OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_SIZE(value_len);
}

static int namevalue_size_xi(struct ocfs2_xattr_info *xi)
{
return namevalue_size(xi->xi_name_len, xi->xi_value_len);
}

static int namevalue_size_xe(struct ocfs2_xattr_entry *xe)
{
u64 value_len = le64_to_cpu(xe->xe_value_size);

BUG_ON((value_len > OCFS2_XATTR_INLINE_SIZE) &&
ocfs2_xattr_is_local(xe));
return namevalue_size(xe->xe_name_len, value_len);
}


static int ocfs2_xattr_bucket_get_name_value(struct super_block *sb,
struct ocfs2_xattr_header *xh,
int index,
Expand Down Expand Up @@ -529,15 +556,20 @@ static void ocfs2_xattr_hash_entry(struct inode *inode,

static int ocfs2_xattr_entry_real_size(int name_len, size_t value_len)
{
int size = 0;
return namevalue_size(name_len, value_len) +
sizeof(struct ocfs2_xattr_entry);
}

if (value_len <= OCFS2_XATTR_INLINE_SIZE)
size = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_SIZE(value_len);
else
size = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_ROOT_SIZE;
size += sizeof(struct ocfs2_xattr_entry);
static int ocfs2_xi_entry_usage(struct ocfs2_xattr_info *xi)
{
return namevalue_size_xi(xi) +
sizeof(struct ocfs2_xattr_entry);
}

return size;
static int ocfs2_xe_entry_usage(struct ocfs2_xattr_entry *xe)
{
return namevalue_size_xe(xe) +
sizeof(struct ocfs2_xattr_entry);
}

int ocfs2_calc_security_init(struct inode *dir,
Expand Down Expand Up @@ -1363,8 +1395,7 @@ static int ocfs2_xattr_cleanup(struct inode *inode,
{
int ret = 0;
void *val = xs->base + offs;
size_t size = OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_ROOT_SIZE;
size_t size = namevalue_size_xi(xi);

ret = vb->vb_access(handle, INODE_CACHE(inode), vb->vb_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
Expand Down Expand Up @@ -1430,8 +1461,7 @@ static int ocfs2_xattr_set_value_outside(struct inode *inode,
{
void *val = xs->base + offs;
struct ocfs2_xattr_value_root *xv = NULL;
size_t size = OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_ROOT_SIZE;
size_t size = namevalue_size_xi(xi);
int ret = 0;

memset(val, 0, size);
Expand Down Expand Up @@ -1490,15 +1520,10 @@ static void ocfs2_xa_block_wipe_namevalue(struct ocfs2_xa_loc *loc)
int namevalue_offset, first_namevalue_offset, namevalue_size;
struct ocfs2_xattr_entry *entry = loc->xl_entry;
struct ocfs2_xattr_header *xh = loc->xl_header;
u64 value_size = le64_to_cpu(entry->xe_value_size);
int count = le16_to_cpu(xh->xh_count);

namevalue_offset = le16_to_cpu(entry->xe_name_offset);
namevalue_size = OCFS2_XATTR_SIZE(entry->xe_name_len);
if (value_size > OCFS2_XATTR_INLINE_SIZE)
namevalue_size += OCFS2_XATTR_ROOT_SIZE;
else
namevalue_size += OCFS2_XATTR_SIZE(value_size);
namevalue_size = namevalue_size_xe(entry);

for (i = 0, first_namevalue_offset = loc->xl_size;
i < count; i++) {
Expand Down Expand Up @@ -1553,17 +1578,8 @@ static void *ocfs2_xa_bucket_offset_pointer(struct ocfs2_xa_loc *loc,

static void ocfs2_xa_bucket_wipe_namevalue(struct ocfs2_xa_loc *loc)
{
int namevalue_size;
struct ocfs2_xattr_entry *entry = loc->xl_entry;
u64 value_size = le64_to_cpu(entry->xe_value_size);

namevalue_size = OCFS2_XATTR_SIZE(entry->xe_name_len);
if (value_size > OCFS2_XATTR_INLINE_SIZE)
namevalue_size += OCFS2_XATTR_ROOT_SIZE;
else
namevalue_size += OCFS2_XATTR_SIZE(value_size);

le16_add_cpu(&loc->xl_header->xh_name_value_len, -namevalue_size);
le16_add_cpu(&loc->xl_header->xh_name_value_len,
-namevalue_size_xe(loc->xl_entry));
}

/* Operations for xattrs stored in buckets. */
Expand Down Expand Up @@ -1683,16 +1699,8 @@ static void ocfs2_xattr_set_entry_local(struct inode *inode,
offs = le16_to_cpu(xs->here->xe_name_offset);
val = xs->base + offs;

if (le64_to_cpu(xs->here->xe_value_size) >
OCFS2_XATTR_INLINE_SIZE)
size = OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_ROOT_SIZE;
else
size = OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_SIZE(le64_to_cpu(xs->here->xe_value_size));

if (xi->xi_value && size == OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_SIZE(xi->xi_value_len)) {
size = namevalue_size_xe(xs->here);
if (xi->xi_value && (size == namevalue_size_xi(xi))) {
/* The old and the new value have the
same size. Just replace the value. */
ocfs2_xattr_set_local(xs->here, 1);
Expand All @@ -1716,8 +1724,7 @@ static void ocfs2_xattr_set_entry_local(struct inode *inode,
}
if (xi->xi_value) {
/* Insert the new name+value. */
size_t size = OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_SIZE(xi->xi_value_len);
size_t size = namevalue_size_xi(xi);
void *val = xs->base + min_offs - size;

xs->here->xe_name_offset = cpu_to_le16(min_offs - size);
Expand Down Expand Up @@ -1788,41 +1795,25 @@ static int ocfs2_xattr_set_entry(struct inode *inode,
if (free < 0)
return -EIO;

if (!xs->not_found) {
size_t size = 0;
if (ocfs2_xattr_is_local(xs->here))
size = OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_SIZE(le64_to_cpu(xs->here->xe_value_size));
else
size = OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_ROOT_SIZE;
free += (size + sizeof(struct ocfs2_xattr_entry));
}
if (!xs->not_found)
free += ocfs2_xe_entry_usage(xs->here);

/* Check free space in inode or block */
if (xi->xi_value && xi->xi_value_len > OCFS2_XATTR_INLINE_SIZE) {
if (free < sizeof(struct ocfs2_xattr_entry) +
OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_ROOT_SIZE) {
if (xi->xi_value) {
if (free < ocfs2_xi_entry_usage(xi)) {
ret = -ENOSPC;
goto out;
}
size_l = OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_ROOT_SIZE;
xi_l.xi_value = (void *)&def_xv;
xi_l.xi_value_len = OCFS2_XATTR_ROOT_SIZE;
} else if (xi->xi_value) {
if (free < sizeof(struct ocfs2_xattr_entry) +
OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_SIZE(xi->xi_value_len)) {
ret = -ENOSPC;
goto out;
if (xi->xi_value_len > OCFS2_XATTR_INLINE_SIZE) {
size_l = namevalue_size_xi(xi);
xi_l.xi_value = (void *)&def_xv;
xi_l.xi_value_len = OCFS2_XATTR_ROOT_SIZE;
}
}

if (!xs->not_found) {
/* For existing extended attribute */
size_t size = OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_SIZE(le64_to_cpu(xs->here->xe_value_size));
size_t size = namevalue_size_xe(xs->here);
size_t offs = le16_to_cpu(xs->here->xe_name_offset);
void *val = xs->base + offs;

Expand Down Expand Up @@ -2589,7 +2580,6 @@ static int ocfs2_xattr_can_be_in_inode(struct inode *inode,
struct ocfs2_xattr_info *xi,
struct ocfs2_xattr_search *xs)
{
u64 value_size;
struct ocfs2_xattr_entry *last;
int free, i;
size_t min_offs = xs->end - xs->base;
Expand All @@ -2612,13 +2602,7 @@ static int ocfs2_xattr_can_be_in_inode(struct inode *inode,

BUG_ON(!xs->not_found);

if (xi->xi_value_len > OCFS2_XATTR_INLINE_SIZE)
value_size = OCFS2_XATTR_ROOT_SIZE;
else
value_size = OCFS2_XATTR_SIZE(xi->xi_value_len);

if (free >= sizeof(struct ocfs2_xattr_entry) +
OCFS2_XATTR_SIZE(xi->xi_name_len) + value_size)
if (free >= (sizeof(struct ocfs2_xattr_entry) + namevalue_size_xi(xi)))
return 1;

return 0;
Expand Down Expand Up @@ -3980,7 +3964,7 @@ static int ocfs2_defrag_xattr_bucket(struct inode *inode,
struct ocfs2_xattr_bucket *bucket)
{
int ret, i;
size_t end, offset, len, value_len;
size_t end, offset, len;
struct ocfs2_xattr_header *xh;
char *entries, *buf, *bucket_buf = NULL;
u64 blkno = bucket_blkno(bucket);
Expand Down Expand Up @@ -4034,12 +4018,7 @@ static int ocfs2_defrag_xattr_bucket(struct inode *inode,
end = OCFS2_XATTR_BUCKET_SIZE;
for (i = 0; i < le16_to_cpu(xh->xh_count); i++, xe++) {
offset = le16_to_cpu(xe->xe_name_offset);
if (ocfs2_xattr_is_local(xe))
value_len = OCFS2_XATTR_SIZE(
le64_to_cpu(xe->xe_value_size));
else
value_len = OCFS2_XATTR_ROOT_SIZE;
len = OCFS2_XATTR_SIZE(xe->xe_name_len) + value_len;
len = namevalue_size_xe(xe);

/*
* We must make sure that the name/value pair
Expand Down Expand Up @@ -4228,7 +4207,7 @@ static int ocfs2_divide_xattr_bucket(struct inode *inode,
int new_bucket_head)
{
int ret, i;
int count, start, len, name_value_len = 0, xe_len, name_offset = 0;
int count, start, len, name_value_len = 0, name_offset = 0;
struct ocfs2_xattr_bucket *s_bucket = NULL, *t_bucket = NULL;
struct ocfs2_xattr_header *xh;
struct ocfs2_xattr_entry *xe;
Expand Down Expand Up @@ -4319,13 +4298,7 @@ static int ocfs2_divide_xattr_bucket(struct inode *inode,
name_value_len = 0;
for (i = 0; i < start; i++) {
xe = &xh->xh_entries[i];
xe_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
if (ocfs2_xattr_is_local(xe))
xe_len +=
OCFS2_XATTR_SIZE(le64_to_cpu(xe->xe_value_size));
else
xe_len += OCFS2_XATTR_ROOT_SIZE;
name_value_len += xe_len;
name_value_len += namevalue_size_xe(xe);
if (le16_to_cpu(xe->xe_name_offset) < name_offset)
name_offset = le16_to_cpu(xe->xe_name_offset);
}
Expand Down Expand Up @@ -4355,12 +4328,6 @@ static int ocfs2_divide_xattr_bucket(struct inode *inode,
xh->xh_free_start = cpu_to_le16(OCFS2_XATTR_BUCKET_SIZE);
for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
xe = &xh->xh_entries[i];
xe_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
if (ocfs2_xattr_is_local(xe))
xe_len +=
OCFS2_XATTR_SIZE(le64_to_cpu(xe->xe_value_size));
else
xe_len += OCFS2_XATTR_ROOT_SIZE;
if (le16_to_cpu(xe->xe_name_offset) <
le16_to_cpu(xh->xh_free_start))
xh->xh_free_start = xe->xe_name_offset;
Expand Down Expand Up @@ -4997,12 +4964,7 @@ static void ocfs2_xattr_set_entry_normal(struct inode *inode,
if (!xs->not_found) {
xe = xs->here;
offs = le16_to_cpu(xe->xe_name_offset);
if (ocfs2_xattr_is_local(xe))
size = OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_SIZE(le64_to_cpu(xe->xe_value_size));
else
size = OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_SIZE(OCFS2_XATTR_ROOT_SIZE);
size = namevalue_size_xe(xe);

/*
* If the new value will be stored outside, xi->xi_value has
Expand All @@ -5011,8 +4973,7 @@ static void ocfs2_xattr_set_entry_normal(struct inode *inode,
* new_size safely here.
* See ocfs2_xattr_set_in_bucket.
*/
new_size = OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_SIZE(xi->xi_value_len);
new_size = namevalue_size_xi(xi);

if (xi->xi_value) {
ocfs2_xa_wipe_namevalue(&loc);
Expand Down Expand Up @@ -5078,8 +5039,7 @@ static void ocfs2_xattr_set_entry_normal(struct inode *inode,

set_new_name_value:
/* Insert the new name+value. */
size = OCFS2_XATTR_SIZE(xi->xi_name_len) +
OCFS2_XATTR_SIZE(xi->xi_value_len);
size = namevalue_size_xi(xi);

/*
* We must make sure that the name/value pair
Expand Down

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