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author | Al Viro <viro@zeniv.linux.org.uk> | 2023-11-25 08:51:35 +0100 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2023-11-25 08:51:35 +0100 |
commit | 119dcc73a9c2df0da002054cdb2296cb32b7cb93 (patch) | |
tree | 0ce7c3532aef1af5055552df0fc7b0302a30c64f /fs/libfs.c | |
parent | __d_unalias() doesn't use inode argument (diff) | |
parent | retain_dentry(): introduce a trimmed-down lockless variant (diff) | |
download | linux-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.c | 45 |
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); |