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| author | Jingbo Xu <jefflexu@linux.alibaba.com> | 2023-07-22 12:45:38 +0300 |
|---|---|---|
| committer | Gao Xiang <hsiangkao@linux.alibaba.com> | 2023-08-11 07:11:44 +0300 |
| commit | fd73a4395d477ae134f319f7368a9f8a6264fd8b (patch) | |
| tree | 1cac2d7b88971fa8513ac6454cbe0bc6770d5df7 /fs/erofs/xattr.c | |
| parent | 3f339920175c871ac63b4ea179117da7518618fd (diff) | |
| download | linux-fd73a4395d477ae134f319f7368a9f8a6264fd8b.tar.xz | |
erofs: boost negative xattr lookup with bloom filter
Optimise the negative xattr lookup with bloom filter.
The bit value for the bloom filter map has a reverse semantics for
compatibility. That is, the bit value of 0 indicates existence, while
the bit value of 1 indicates the absence of corresponding xattr.
The initial version is _only_ enabled when xattr_filter_reserved is
zero. The filter map internals may change in the future, in which case
the reserved flag will be set non-zero and we don't need bothering the
compatible bits again at that time. For now disable the optimization if
this reserved flag is non-zero.
Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230722094538.11754-3-jefflexu@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Diffstat (limited to 'fs/erofs/xattr.c')
| -rw-r--r-- | fs/erofs/xattr.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c index 40178b6e0688..09d341675e89 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_name_filter = le32_to_cpu(ih->h_name_filter); vi->xattr_shared_count = ih->h_shared_count; vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count, sizeof(uint), GFP_KERNEL); @@ -392,7 +394,10 @@ int erofs_getxattr(struct inode *inode, int index, const char *name, void *buffer, size_t buffer_size) { int ret; + unsigned int hashbit; struct erofs_xattr_iter it; + struct erofs_inode *vi = EROFS_I(inode); + struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb); if (!name) return -EINVAL; @@ -401,6 +406,15 @@ int erofs_getxattr(struct inode *inode, int index, const char *name, if (ret) return ret; + /* reserved flag is non-zero if there's any change of on-disk format */ + if (erofs_sb_has_xattr_filter(sbi) && !sbi->xattr_filter_reserved) { + hashbit = xxh32(name, strlen(name), + EROFS_XATTR_FILTER_SEED + index); + hashbit &= EROFS_XATTR_FILTER_BITS - 1; + if (vi->xattr_name_filter & (1U << hashbit)) + return -ENOATTR; + } + it.index = index; it.name = (struct qstr)QSTR_INIT(name, strlen(name)); if (it.name.len > EROFS_NAME_LEN) |