On 2025/3/1 22:49, Hongzhen Luo wrote:
When creating the EROFS image, users can specify the fingerprint name.
This is to prepare for the upcoming inode page cache share.
Signed-off-by: Hongzhen Luo <hongz...@linux.alibaba.com>
---
fs/erofs/Kconfig | 10 +++++++++
fs/erofs/erofs_fs.h | 9 ++++++---
fs/erofs/internal.h | 6 ++++++
fs/erofs/super.c | 4 ++++
fs/erofs/xattr.c | 49 +++++++++++++++++++++++++++++++++++++++++++++
fs/erofs/xattr.h | 6 ++++++
6 files changed, 81 insertions(+), 3 deletions(-)
diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index 6ea60661fa55..d2416d35035a 100644
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -178,3 +178,13 @@ config EROFS_FS_PCPU_KTHREAD_HIPRI
at higher priority.
If unsure, say N.
+
+config EROFS_FS_INODE_SHARE
+ bool "EROFS inode page cache share support"
+ depends on EROFS_FS && EROFS_FS_XATTR
+ default n
+ help
+ This permits EROFS to share page cache for files with same
+ fingerprints.
+
+ If unsure, say N.
diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h
index 199395ed1c1f..261bd9bd47c4 100644
--- a/fs/erofs/erofs_fs.h
+++ b/fs/erofs/erofs_fs.h
@@ -30,6 +30,7 @@
#define EROFS_FEATURE_INCOMPAT_FRAGMENTS 0x00000020
#define EROFS_FEATURE_INCOMPAT_DEDUPE 0x00000020
#define EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES 0x00000040
+#define EROFS_FEATURE_INCOMPAT_ISHARE_KEY 0x00000080
#define EROFS_ALL_FEATURE_INCOMPAT \
(EROFS_FEATURE_INCOMPAT_ZERO_PADDING | \
EROFS_FEATURE_INCOMPAT_COMPR_CFGS | \
@@ -40,7 +41,8 @@
EROFS_FEATURE_INCOMPAT_ZTAILPACKING | \
EROFS_FEATURE_INCOMPAT_FRAGMENTS | \
EROFS_FEATURE_INCOMPAT_DEDUPE | \
- EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES)
+ EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES | \
+ EROFS_FEATURE_INCOMPAT_ISHARE_KEY)
#define EROFS_SB_EXTSLOT_SIZE 16
@@ -84,8 +86,9 @@ struct erofs_super_block {
__le32 xattr_prefix_start; /* start of long xattr prefixes */
__le64 packed_nid; /* nid of the special packed inode */
__u8 xattr_filter_reserved; /* reserved for xattr name filter */
- __u8 reserved2[23];
-};
+ __le32 ishare_key_start; /* start of ishare key */
+ __u8 reserved2[19];
+} __packed;
/*
* EROFS inode datalayout (i_format in on-disk inode):
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 47004eb89838..21bf9b694048 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -166,6 +166,11 @@ struct erofs_sb_info {
struct erofs_domain *domain;
char *fsid;
char *domain_id;
+
+ /* inode page cache share support */
+ u32 ishare_key_start;
+ int ishare_key_idx;
+ char *ishare_key;
};
#define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
@@ -233,6 +238,7 @@ EROFS_FEATURE_FUNCS(ztailpacking, incompat,
INCOMPAT_ZTAILPACKING)
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(ishare_key, incompat, INCOMPAT_ISHARE_KEY)
EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)
EROFS_FEATURE_FUNCS(xattr_filter, compat, COMPAT_XATTR_FILTER)
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index eb052a770088..6af02cc8b8c6 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -313,6 +313,8 @@ static int erofs_read_superblock(struct super_block *sb)
sbi->packed_nid = le64_to_cpu(dsb->packed_nid);
sbi->inos = le64_to_cpu(dsb->inos);
+ sbi->ishare_key_start = le32_to_cpu(dsb->ishare_key_start);
+
sbi->build_time = le64_to_cpu(dsb->build_time);
sbi->build_time_nsec = le32_to_cpu(dsb->build_time_nsec);
@@ -676,6 +678,8 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
if (err)
return err;
+ erofs_xattr_set_ishare_key(sb);
+
erofs_set_sysfs_name(sb);
err = erofs_register_sysfs(sb);
if (err)
diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c
index 7940241d9355..30a64ac3239a 100644
--- a/fs/erofs/xattr.c
+++ b/fs/erofs/xattr.c
@@ -549,3 +549,52 @@ struct posix_acl *erofs_get_acl(struct inode *inode, int
type, bool rcu)
return acl;
}
#endif
+
+#ifdef CONFIG_EROFS_FS_INODE_SHARE
+void erofs_xattr_set_ishare_key(struct super_block *sb)
+{
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
+ struct xattr_handler const *handler;
+ erofs_off_t pos;
+ char *key;
+ int len, i;
+ void *ptr;
+
+ if (!erofs_sb_has_fragments(sbi) || !erofs_sb_has_ishare_key(sbi) ||
+ !sbi->packed_inode)
+ return;
+
+ buf.mapping = sbi->packed_inode->i_mapping;
+ pos = sbi->ishare_key_start << 2;
+ ptr = erofs_read_metadata(sb, &buf, &pos, &len);
+
+ if (IS_ERR(ptr)) {
+ erofs_put_metabuf(&buf);
+ return;
+ }
+
+ for (i = 0; ARRAY_SIZE(erofs_xattr_handlers); i++) {
ARRAY_SIZE will get the length of array erofs_xattr_handlers, here you
must forget it. So here it should be i <
ARRAY_SIZE(erofs_xattr_handlers) - 1. :)
+ handler = erofs_xattr_handlers[i];
+ if (!handler)
+ break;
+ if (!memcmp(handler->prefix, ptr, strlen(handler->prefix)))
+ break;
+ }
+
+ if (!handler)
+ return;
This exception branch lacks a call to erofs_put_metabuf(&buf).
+
+ len -= strlen(handler->prefix);
+ key = kzalloc(len + 1, GFP_KERNEL);
+ if (!key) {
+ erofs_put_metabuf(&buf);
+ return;
+ }
+
+ memcpy(key, ptr + strlen(handler->prefix), len);
+ sbi->ishare_key = key;
+ sbi->ishare_key_idx = handler->flags;
+ erofs_put_metabuf(&buf);
+}
+#endif
diff --git a/fs/erofs/xattr.h b/fs/erofs/xattr.h
index b246cd0e135e..24a243165417 100644
--- a/fs/erofs/xattr.h
+++ b/fs/erofs/xattr.h
@@ -70,4 +70,10 @@ struct posix_acl *erofs_get_acl(struct inode *inode, int
type, bool rcu);
#define erofs_get_acl (NULL)
#endif
+#ifdef CONFIG_EROFS_FS_INODE_SHARE
+void erofs_xattr_set_ishare_key(struct super_block *sb);
+#else
+static inline void erofs_xattr_set_ishare_key(struct super_block *sb) {}
+#endif
+
#endif
