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authorAl Viro <viro@zeniv.linux.org.uk>2023-11-25 08:51:35 +0100
committerAl Viro <viro@zeniv.linux.org.uk>2023-11-25 08:51:35 +0100
commit119dcc73a9c2df0da002054cdb2296cb32b7cb93 (patch)
tree0ce7c3532aef1af5055552df0fc7b0302a30c64f /fs/libfs.c
parent__d_unalias() doesn't use inode argument (diff)
parentretain_dentry(): introduce a trimmed-down lockless variant (diff)
downloadlinux-119dcc73a9c2df0da002054cdb2296cb32b7cb93.tar.xz
linux-119dcc73a9c2df0da002054cdb2296cb32b7cb93.zip
Merge branches 'work.dcache-misc' and 'work.dcache2' into work.dcache
Diffstat (limited to 'fs/libfs.c')
-rw-r--r--fs/libfs.c45
1 files changed, 21 insertions, 24 deletions
diff --git a/fs/libfs.c b/fs/libfs.c
index 6fa8ad36049f..75eeb9621e20 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -104,15 +104,16 @@ EXPORT_SYMBOL(dcache_dir_close);
* If no such element exists, NULL is returned.
*/
static struct dentry *scan_positives(struct dentry *cursor,
- struct list_head *p,
+ struct hlist_node **p,
loff_t count,
struct dentry *last)
{
struct dentry *dentry = cursor->d_parent, *found = NULL;
spin_lock(&dentry->d_lock);
- while ((p = p->next) != &dentry->d_subdirs) {
- struct dentry *d = list_entry(p, struct dentry, d_child);
+ while (*p) {
+ struct dentry *d = hlist_entry(*p, struct dentry, d_sib);
+ p = &d->d_sib.next;
// we must at least skip cursors, to avoid livelocks
if (d->d_flags & DCACHE_DENTRY_CURSOR)
continue;
@@ -126,8 +127,10 @@ static struct dentry *scan_positives(struct dentry *cursor,
count = 1;
}
if (need_resched()) {
- list_move(&cursor->d_child, p);
- p = &cursor->d_child;
+ if (!hlist_unhashed(&cursor->d_sib))
+ __hlist_del(&cursor->d_sib);
+ hlist_add_behind(&cursor->d_sib, &d->d_sib);
+ p = &cursor->d_sib.next;
spin_unlock(&dentry->d_lock);
cond_resched();
spin_lock(&dentry->d_lock);
@@ -159,13 +162,12 @@ loff_t dcache_dir_lseek(struct file *file, loff_t offset, int whence)
inode_lock_shared(dentry->d_inode);
if (offset > 2)
- to = scan_positives(cursor, &dentry->d_subdirs,
+ to = scan_positives(cursor, &dentry->d_children.first,
offset - 2, NULL);
spin_lock(&dentry->d_lock);
+ hlist_del_init(&cursor->d_sib);
if (to)
- list_move(&cursor->d_child, &to->d_child);
- else
- list_del_init(&cursor->d_child);
+ hlist_add_behind(&cursor->d_sib, &to->d_sib);
spin_unlock(&dentry->d_lock);
dput(to);
@@ -187,19 +189,16 @@ int dcache_readdir(struct file *file, struct dir_context *ctx)
{
struct dentry *dentry = file->f_path.dentry;
struct dentry *cursor = file->private_data;
- struct list_head *anchor = &dentry->d_subdirs;
struct dentry *next = NULL;
- struct list_head *p;
+ struct hlist_node **p;
if (!dir_emit_dots(file, ctx))
return 0;
if (ctx->pos == 2)
- p = anchor;
- else if (!list_empty(&cursor->d_child))
- p = &cursor->d_child;
+ p = &dentry->d_children.first;
else
- return 0;
+ p = &cursor->d_sib.next;
while ((next = scan_positives(cursor, p, 1, next)) != NULL) {
if (!dir_emit(ctx, next->d_name.name, next->d_name.len,
@@ -207,13 +206,12 @@ int dcache_readdir(struct file *file, struct dir_context *ctx)
fs_umode_to_dtype(d_inode(next)->i_mode)))
break;
ctx->pos++;
- p = &next->d_child;
+ p = &next->d_sib.next;
}
spin_lock(&dentry->d_lock);
+ hlist_del_init(&cursor->d_sib);
if (next)
- list_move_tail(&cursor->d_child, &next->d_child);
- else
- list_del_init(&cursor->d_child);
+ hlist_add_before(&cursor->d_sib, &next->d_sib);
spin_unlock(&dentry->d_lock);
dput(next);
@@ -492,12 +490,11 @@ const struct file_operations simple_offset_dir_operations = {
static struct dentry *find_next_child(struct dentry *parent, struct dentry *prev)
{
- struct dentry *child = NULL;
- struct list_head *p = prev ? &prev->d_child : &parent->d_subdirs;
+ struct dentry *child = NULL, *d;
spin_lock(&parent->d_lock);
- while ((p = p->next) != &parent->d_subdirs) {
- struct dentry *d = container_of(p, struct dentry, d_child);
+ d = prev ? d_next_sibling(prev) : d_first_child(parent);
+ hlist_for_each_entry_from(d, d_sib) {
if (simple_positive(d)) {
spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
if (simple_positive(d))
@@ -658,7 +655,7 @@ int simple_empty(struct dentry *dentry)
int ret = 0;
spin_lock(&dentry->d_lock);
- list_for_each_entry(child, &dentry->d_subdirs, d_child) {
+ hlist_for_each_entry(child, &dentry->d_children, d_sib) {
spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
if (simple_positive(child)) {
spin_unlock(&child->d_lock);