Boost the negative xattr lookup with bloom filter. The bit value for the bloom filter map has a reverse semantics for compatibility. That is, the mapped bits will be cleared to 0, while the bit value of 1 indicates the absence of corresponding xattr.
Signed-off-by: Jingbo Xu <jeffl...@linux.alibaba.com> --- fs/erofs/internal.h | 2 ++ fs/erofs/xattr.c | 16 +++++++++++++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index 1e39c03357d1..49b4b350af8a 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -285,6 +285,7 @@ EROFS_FEATURE_FUNCS(fragments, incompat, INCOMPAT_FRAGMENTS) EROFS_FEATURE_FUNCS(dedupe, incompat, INCOMPAT_DEDUPE) EROFS_FEATURE_FUNCS(xattr_prefixes, incompat, INCOMPAT_XATTR_PREFIXES) EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM) +EROFS_FEATURE_FUNCS(xattr_bloom, compat, COMPAT_XATTR_BLOOM) /* atomic flag definitions */ #define EROFS_I_EA_INITED_BIT 0 @@ -304,6 +305,7 @@ struct erofs_inode { unsigned char inode_isize; unsigned int xattr_isize; + unsigned long xattr_bloom_map; unsigned int xattr_shared_count; unsigned int *xattr_shared_xattrs; diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c index 4376f654474d..1ab481b46e8d 100644 --- a/fs/erofs/xattr.c +++ b/fs/erofs/xattr.c @@ -5,6 +5,7 @@ * Copyright (C) 2021-2022, Alibaba Cloud */ #include <linux/security.h> +#include <linux/xxhash.h> #include "xattr.h" struct erofs_xattr_iter { @@ -87,6 +88,7 @@ static int erofs_init_inode_xattrs(struct inode *inode) } ih = it.kaddr + erofs_blkoff(sb, it.pos); + vi->xattr_bloom_map = le32_to_cpu(ih->h_map); vi->xattr_shared_count = ih->h_shared_count; vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count, sizeof(uint), GFP_KERNEL); @@ -392,8 +394,11 @@ int erofs_getxattr(struct inode *inode, int index, const char *name, void *buffer, size_t buffer_size) { - int ret; + int i, ret; + uint32_t bit; struct erofs_xattr_iter it; + struct erofs_inode *const vi = EROFS_I(inode); + struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb); if (!name) return -EINVAL; @@ -402,6 +407,15 @@ int erofs_getxattr(struct inode *inode, int index, if (ret) return ret; + if (erofs_sb_has_xattr_bloom(sbi) && vi->xattr_bloom_map) { + for (i = 0; i < EROFS_XATTR_BLOOM_COUNTS; i++) { + bit = xxh32(name, strlen(name), index + i); + bit &= EROFS_XATTR_BLOOM_MASK; + if (test_bit(bit, &vi->xattr_bloom_map)) + return -ENOATTR; + } + } + it.index = index; it.name = (struct qstr)QSTR_INIT(name, strlen(name)); if (it.name.len > EROFS_NAME_LEN) -- 2.19.1.6.gb485710b