| Message ID | 20241010112543.1609648-2-yebin@huaweicloud.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | add support for drop_caches for individual filesystem | expand |
On Thu 10-10-24 19:25:41, Ye Bin wrote: > From: Ye Bin <yebin10@huawei.com> > > This patch is prepare for support drop_caches for specify file system. > shrink_icache_sb() helper walk the superblock inode LRU for freeable inodes > and attempt to free them. > > Signed-off-by: Ye Bin <yebin10@huawei.com> > --- > fs/inode.c | 17 +++++++++++++++++ > fs/internal.h | 1 + > 2 files changed, 18 insertions(+) > > diff --git a/fs/inode.c b/fs/inode.c > index 1939f711d2c9..2129b48571b4 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -1045,6 +1045,23 @@ long prune_icache_sb(struct super_block *sb, struct shrink_control *sc) > return freed; > } > > +/* > + * Walk the superblock inode LRU for freeable inodes and attempt to free them. > + * Inodes to be freed are moved to a temporary list and then are freed outside > + * inode_lock by dispose_list(). > + */ > +void shrink_icache_sb(struct super_block *sb) > +{ > + do { > + LIST_HEAD(dispose); > + > + list_lru_walk(&sb->s_inode_lru, inode_lru_isolate, > + &dispose, 1024); > + dispose_list(&dispose); > + } while (list_lru_count(&sb->s_inode_lru) > 0); > +} > +EXPORT_SYMBOL(shrink_icache_sb); Hum, but this will livelock if we cannot remove all the inodes? Now I guess inode_lru_isolate() usually removes busy inodes from the LRU so this should not happen in practice but such behavior is not guaranteed (we can LRU_SKIP inodes if i_lock is busy or LRU_RETRY if inode has page cache pages). So I think we need some safety net here... Honza
diff --git a/fs/inode.c b/fs/inode.c index 1939f711d2c9..2129b48571b4 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1045,6 +1045,23 @@ long prune_icache_sb(struct super_block *sb, struct shrink_control *sc) return freed; } +/* + * Walk the superblock inode LRU for freeable inodes and attempt to free them. + * Inodes to be freed are moved to a temporary list and then are freed outside + * inode_lock by dispose_list(). + */ +void shrink_icache_sb(struct super_block *sb) +{ + do { + LIST_HEAD(dispose); + + list_lru_walk(&sb->s_inode_lru, inode_lru_isolate, + &dispose, 1024); + dispose_list(&dispose); + } while (list_lru_count(&sb->s_inode_lru) > 0); +} +EXPORT_SYMBOL(shrink_icache_sb); + static void __wait_on_freeing_inode(struct inode *inode, bool is_inode_hash_locked); /* * Called with the inode lock held. diff --git a/fs/internal.h b/fs/internal.h index 81c7a085355c..cee79141e308 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -199,6 +199,7 @@ extern int vfs_open(const struct path *, struct file *); * inode.c */ extern long prune_icache_sb(struct super_block *sb, struct shrink_control *sc); +extern void shrink_icache_sb(struct super_block *sb); int dentry_needs_remove_privs(struct mnt_idmap *, struct dentry *dentry); bool in_group_or_capable(struct mnt_idmap *idmap, const struct inode *inode, vfsgid_t vfsgid);