[Ocfs2-devel] [PATCH 05/14] ocfs2: Wrap calculation of name+value pair size.
Joel Becker
joel.becker at oracle.com
Fri Aug 28 01:35:54 PDT 2009
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 at oracle.com>
---
fs/ocfs2/xattr.c | 170 +++++++++++++++++++++---------------------------------
1 files changed, 65 insertions(+), 105 deletions(-)
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index b92c775..4c5c566 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -187,6 +187,33 @@ 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,
@@ -535,15 +562,20 @@ 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,
@@ -1369,8 +1401,7 @@ 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);
@@ -1436,8 +1467,7 @@ 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);
@@ -1498,15 +1528,10 @@ 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++) {
@@ -1560,17 +1585,8 @@ 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. */
@@ -1689,16 +1705,8 @@ 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);
@@ -1722,8 +1730,7 @@ 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);
@@ -1794,41 +1801,25 @@ 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;
@@ -2595,7 +2586,6 @@ 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;
@@ -2618,13 +2608,7 @@ 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;
@@ -3986,7 +3970,7 @@ 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);
@@ -4040,12 +4024,7 @@ 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
@@ -4234,7 +4213,7 @@ 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;
@@ -4325,13 +4304,7 @@ 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);
}
@@ -4361,12 +4334,6 @@ 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;
@@ -5003,12 +4970,7 @@ 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
@@ -5017,8 +4979,7 @@ 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);
@@ -5084,8 +5045,7 @@ 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
--
1.6.3.3
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