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| author | Imran Khan <imran.f.khan@oracle.com> | 2023-03-09 12:09:32 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-29 12:23:45 +0200 |
| commit | 06fb4736139fde0e1431fe2a5b4912dcb7588d09 (patch) | |
| tree | 25d2e93df9103be9b2f7a901e0215f1e2a6faef9 /fs/kernfs | |
| parent | kernfs: Use a per-fs rwsem to protect per-fs list of kernfs_super_info. (diff) | |
| download | linux-06fb4736139fde0e1431fe2a5b4912dcb7588d09.tar.xz linux-06fb4736139fde0e1431fe2a5b4912dcb7588d09.zip | |
kernfs: change kernfs_rename_lock into a read-write lock.
kernfs_rename_lock protects a node's ->parent and thus kernfs topology.
Thus it can be used in cases that rely on a stable kernfs topology.
Change it to a read-write lock for better scalability.
Suggested by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Imran Khan <imran.f.khan@oracle.com>
Link: https://lore.kernel.org/r/20230309110932.2889010-4-imran.f.khan@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/kernfs')
| -rw-r--r-- | fs/kernfs/dir.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 2cdb8516e528..06e27b36216f 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -17,7 +17,7 @@ #include "kernfs-internal.h" -static DEFINE_SPINLOCK(kernfs_rename_lock); /* kn->parent and ->name */ +static DEFINE_RWLOCK(kernfs_rename_lock); /* kn->parent and ->name */ /* * Don't use rename_lock to piggy back on pr_cont_buf. We don't want to * call pr_cont() while holding rename_lock. Because sometimes pr_cont() @@ -196,9 +196,9 @@ int kernfs_name(struct kernfs_node *kn, char *buf, size_t buflen) unsigned long flags; int ret; - spin_lock_irqsave(&kernfs_rename_lock, flags); + read_lock_irqsave(&kernfs_rename_lock, flags); ret = kernfs_name_locked(kn, buf, buflen); - spin_unlock_irqrestore(&kernfs_rename_lock, flags); + read_unlock_irqrestore(&kernfs_rename_lock, flags); return ret; } @@ -224,9 +224,9 @@ int kernfs_path_from_node(struct kernfs_node *to, struct kernfs_node *from, unsigned long flags; int ret; - spin_lock_irqsave(&kernfs_rename_lock, flags); + read_lock_irqsave(&kernfs_rename_lock, flags); ret = kernfs_path_from_node_locked(to, from, buf, buflen); - spin_unlock_irqrestore(&kernfs_rename_lock, flags); + read_unlock_irqrestore(&kernfs_rename_lock, flags); return ret; } EXPORT_SYMBOL_GPL(kernfs_path_from_node); @@ -294,10 +294,10 @@ struct kernfs_node *kernfs_get_parent(struct kernfs_node *kn) struct kernfs_node *parent; unsigned long flags; - spin_lock_irqsave(&kernfs_rename_lock, flags); + read_lock_irqsave(&kernfs_rename_lock, flags); parent = kn->parent; kernfs_get(parent); - spin_unlock_irqrestore(&kernfs_rename_lock, flags); + read_unlock_irqrestore(&kernfs_rename_lock, flags); return parent; } @@ -1731,7 +1731,7 @@ int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, kernfs_get(new_parent); /* rename_lock protects ->parent and ->name accessors */ - spin_lock_irq(&kernfs_rename_lock); + write_lock_irq(&kernfs_rename_lock); old_parent = kn->parent; kn->parent = new_parent; @@ -1742,7 +1742,7 @@ int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, kn->name = new_name; } - spin_unlock_irq(&kernfs_rename_lock); + write_unlock_irq(&kernfs_rename_lock); kn->hash = kernfs_name_hash(kn->name, kn->ns); kernfs_link_sibling(kn); |