fs: change d_compare for rcu-walk

Change d_compare so it may be called from lock-free RCU lookups. This
does put significant restrictions on what may be done from the callback,
however there don't seem to have been any problems with in-tree fses.
If some strange use case pops up that _really_ cannot cope with the
rcu-walk rules, we can just add new rcu-unaware callbacks, which would
cause name lookup to drop out of rcu-walk mode.

For in-tree filesystems, this is just a mechanical change.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
This commit is contained in:
Nick Piggin 2011-01-07 17:49:27 +11:00
parent fb2d5b86af
commit 621e155a35
23 changed files with 242 additions and 157 deletions

View file

@ -363,9 +363,12 @@ int hfsplus_hash_dentry(struct dentry *dentry, struct qstr *str)
* Composed unicode characters are decomposed and case-folding is performed
* if the appropriate bits are (un)set on the superblock.
*/
int hfsplus_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *s2)
int hfsplus_compare_dentry(const struct dentry *parent,
const struct inode *pinode,
const struct dentry *dentry, const struct inode *inode,
unsigned int len, const char *str, const struct qstr *name)
{
struct super_block *sb = dentry->d_sb;
struct super_block *sb = parent->d_sb;
int casefold, decompose, size;
int dsize1, dsize2, len1, len2;
const u16 *dstr1, *dstr2;
@ -375,10 +378,10 @@ int hfsplus_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *
casefold = test_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags);
decompose = !test_bit(HFSPLUS_SB_NODECOMPOSE, &HFSPLUS_SB(sb)->flags);
astr1 = s1->name;
len1 = s1->len;
astr2 = s2->name;
len2 = s2->len;
astr1 = str;
len1 = len;
astr2 = name->name;
len2 = name->len;
dsize1 = dsize2 = 0;
dstr1 = dstr2 = NULL;