[PATCH 4/6] fuse2fs: enable caching IO manager

Darrick J. Wong
2025-08-21T01:24:19Z

Enable the new dynamic iocache I/O manager in the fuse server, and turn
off all the other cache control.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
misc/Makefile.in | 7 ++++-
misc/fuse2fs.c | 71 ++++--------------------------------------------------
misc/fuse4fs.c | 69 ++--------------------------------------------------
3 files changed, 13 insertions(+), 134 deletions(-)

diff --git a/misc/Makefile.in b/misc/Makefile.in
index 36694d682d3b59..8a31b7fc42e643 100644
--- a/misc/Makefile.in
+++ b/misc/Makefile.in
@@ -891,7 +891,9 @@ fuse2fs.o: $(srcdir)/fuse2fs.c $(top_builddir)/lib/config.h \
$(top_srcdir)/lib/ext2fs/ext2_ext_attr.h $(top_srcdir)/lib/ext2fs/hashmap.h \
$(top_srcdir)/lib/ext2fs/bitops.h $(top_srcdir)/lib/ext2fs/ext2fsP.h \
$(top_srcdir)/lib/ext2fs/ext2fs.h $(top_srcdir)/version.h \
- $(top_srcdir)/lib/e2p/e2p.h
+ $(top_srcdir)/lib/e2p/e2p.h $(top_srcdir)/lib/support/cache.h \
+ $(top_srcdir)/lib/support/list.h $(top_srcdir)/lib/support/xbitops.h \
+ $(top_srcdir)/lib/support/iocache.h
fuse4fs.o: $(srcdir)/fuse4fs.c $(top_builddir)/lib/config.h \
$(top_builddir)/lib/dirpaths.h $(top_srcdir)/lib/ext2fs/ext2fs.h \
$(top_builddir)/lib/ext2fs/ext2_types.h $(top_srcdir)/lib/ext2fs/ext2_fs.h \
@@ -901,7 +903,8 @@ fuse4fs.o: $(srcdir)/fuse4fs.c $(top_builddir)/lib/config.h \
$(top_srcdir)/lib/ext2fs/bitops.h $(top_srcdir)/lib/ext2fs/ext2fsP.h \
$(top_srcdir)/lib/ext2fs/ext2fs.h $(top_srcdir)/version.h \
$(top_srcdir)/lib/e2p/e2p.h $(top_srcdir)/lib/support/cache.h \
- $(top_srcdir)/lib/support/list.h $(top_srcdir)/lib/support/xbitops.h
+ $(top_srcdir)/lib/support/list.h $(top_srcdir)/lib/support/xbitops.h \
+ $(top_srcdir)/lib/support/iocache.h
e2fuzz.o: $(srcdir)/e2fuzz.c $(top_builddir)/lib/config.h \
$(top_builddir)/lib/dirpaths.h $(top_srcdir)/lib/ext2fs/ext2_fs.h \
$(top_builddir)/lib/ext2fs/ext2_types.h $(top_srcdir)/lib/ext2fs/ext2fs.h \
diff --git a/misc/fuse2fs.c b/misc/fuse2fs.c
index f5d68cc549ad69..d3ac5f7b6627cd 100644
--- a/misc/fuse2fs.c
+++ b/misc/fuse2fs.c
@@ -50,6 +50,9 @@
#include "ext2fs/ext2fs.h"
#include "ext2fs/ext2_fs.h"
#include "ext2fs/ext2fsP.h"
+#include "support/list.h"
+#include "support/cache.h"
+#include "support/iocache.h"
#if FUSE_VERSION >= FUSE_MAKE_VERSION(3, 0)
# define FUSE_PLATFORM_OPTS ""
#else
@@ -290,7 +293,6 @@ struct fuse2fs {
unsigned int blockmask;
unsigned long offset;
unsigned int next_generation;
- unsigned long long cache_size;
char *lockfile;
#ifdef HAVE_CLOCK_MONOTONIC
struct timespec lock_start_time;
@@ -1122,7 +1124,7 @@ static errcode_t fuse2fs_open(struct fuse2fs *ff, int libext2_flags)

dbg_printf(ff, "opening with flags=0x%x\n", flags);

- err = ext2fs_open2(ff->device, options, flags, 0, 0, unix_io_manager,
+ err = ext2fs_open2(ff->device, options, flags, 0, 0, iocache_io_manager,
&ff->fs);
if (err == EPERM) {
err_printf(ff, "%s.\n",
@@ -1150,25 +1152,6 @@ static inline bool fuse2fs_on_bdev(const struct fuse2fs *ff)
return ff->fs->io->flags & CHANNEL_FLAGS_BLOCK_DEVICE;
}

-static errcode_t fuse2fs_config_cache(struct fuse2fs *ff)
-{
- char buf[128];
- errcode_t err;
-
- snprintf(buf, sizeof(buf), "cache_blocks=%llu",
- FUSE2FS_B_TO_FSBT(ff, ff->cache_size));
- err = io_channel_set_options(ff->fs->io, buf);
- if (err) {
- err_printf(ff, "%s %lluk: %s\n",
- _("cannot set disk cache size to"),
- ff->cache_size >> 10,
- error_message(err));
- return err;
- }
-
- return 0;
-}
-
static errcode_t fuse2fs_check_support(struct fuse2fs *ff)
{
ext2_filsys fs = ff->fs;
@@ -6829,7 +6812,6 @@ enum {
FUSE2FS_VERSION,
FUSE2FS_HELP,
FUSE2FS_HELPFULL,
- FUSE2FS_CACHE_SIZE,
FUSE2FS_DIRSYNC,
FUSE2FS_ERRORS_BEHAVIOR,
#ifdef HAVE_FUSE_IOMAP
@@ -6879,7 +6861,6 @@ static struct fuse_opt fuse2fs_opts[] = {
FUSE_OPT_KEY("user_xattr", FUSE2FS_IGNORED),
FUSE_OPT_KEY("noblock_validity", FUSE2FS_IGNORED),
FUSE_OPT_KEY("nodelalloc", FUSE2FS_IGNORED),
- FUSE_OPT_KEY("cache_size=%s", FUSE2FS_CACHE_SIZE),
FUSE_OPT_KEY("dirsync", FUSE2FS_DIRSYNC),
FUSE_OPT_KEY("errors=%s", FUSE2FS_ERRORS_BEHAVIOR),
#ifdef HAVE_FUSE_IOMAP
@@ -6918,16 +6899,6 @@ static int fuse2fs_opt_proc(void *data, const char *arg,
return 0;
}
return 1;
- case FUSE2FS_CACHE_SIZE:
- ff->cache_size = parse_num_blocks2(arg + 11, -1);
- if (ff->cache_size < 1 || ff->cache_size > INT32_MAX) {
- fprintf(stderr, "%s: %s\n", arg,
- _("cache size must be between 1 block and 2GB."));
- return -1;
- }
-
- /* do not pass through to libfuse */
- return 0;
case FUSE2FS_ERRORS_BEHAVIOR:
if (strcmp(arg + 7, "continue") == 0)
ff->errors_behavior = EXT2_ERRORS_CONTINUE;
@@ -6984,7 +6955,6 @@ static int fuse2fs_opt_proc(void *data, const char *arg,
" -o kernel run this as if it were the kernel, which sets:\n"
" allow_others,default_permissions,suid,dev\n"
" -o directio use O_DIRECT to read and write the disk\n"
- " -o cache_size=N[KMG] use a disk cache of this size\n"
" -o errors= behavior when an error is encountered:\n"
" continue|remount-ro|panic\n"
#ifdef HAVE_FUSE_IOMAP
@@ -7028,28 +6998,6 @@ static const char *get_subtype(const char *argv0)
return "ext4";
}

-/* Figure out a reasonable default size for the disk cache */
-static unsigned long long default_cache_size(void)
-{
- long pages = 0, pagesize = 0;
- unsigned long long max_cache;
- unsigned long long ret = 32ULL << 20; /* 32 MB */
-
-#ifdef _SC_PHYS_PAGES
- pages = sysconf(_SC_PHYS_PAGES);
-#endif
-#ifdef _SC_PAGESIZE
- pagesize = sysconf(_SC_PAGESIZE);
-#endif
- if (pages > 0 && pagesize > 0) {
- max_cache = (unsigned long long)pagesize * pages / 20;
-
- if (max_cache > 0 && ret > max_cache)
- ret = max_cache;
- }
- return ret;
-}
-
#ifdef HAVE_FUSE_IOMAP
static inline bool fuse2fs_discover_iomap(struct fuse2fs *ff)
{
@@ -7170,6 +7118,7 @@ int main(int argc, char *argv[])
fctx.alloc_all_blocks = 1;
}

+ iocache_set_backing_manager(unix_io_manager);
err = fuse2fs_open(&fctx, EXT2_FLAG_EXCLUSIVE);
if (err) {
ret = 32;
@@ -7206,16 +7155,6 @@ int main(int argc, char *argv[])
goto out;
}

- if (!fctx.cache_size)
- fctx.cache_size = default_cache_size();
- if (fctx.cache_size) {
- err = fuse2fs_config_cache(&fctx);
- if (err) {
- ret = 32;
- goto out;
- }
- }
-
err = fuse2fs_check_support(&fctx);
if (err) {
ret = 32;
diff --git a/misc/fuse4fs.c b/misc/fuse4fs.c
index 6f03c6a0933a3d..85d73a9088d237 100644
--- a/misc/fuse4fs.c
+++ b/misc/fuse4fs.c
@@ -53,6 +53,7 @@
#include "ext2fs/ext2fsP.h"
#include "support/list.h"
#include "support/cache.h"
+#include "support/iocache.h"

#include "../version.h"
#include "uuid/uuid.h"
@@ -286,7 +287,6 @@ struct fuse4fs {
unsigned int blockmask;
unsigned long offset;
unsigned int next_generation;
- unsigned long long cache_size;
char *lockfile;
#ifdef HAVE_CLOCK_MONOTONIC
struct timespec lock_start_time;
@@ -1281,7 +1281,7 @@ static errcode_t fuse4fs_open(struct fuse4fs *ff, int libext2_flags)

dbg_printf(ff, "opening with flags=0x%x\n", flags);

- err = ext2fs_open2(ff->device, options, flags, 0, 0, unix_io_manager,
+ err = ext2fs_open2(ff->device, options, flags, 0, 0, iocache_io_manager,
&ff->fs);
if (err == EPERM) {
err_printf(ff, "%s.\n",
@@ -1313,25 +1313,6 @@ static inline bool fuse4fs_on_bdev(const struct fuse4fs *ff)
return ff->fs->io->flags & CHANNEL_FLAGS_BLOCK_DEVICE;
}

-static errcode_t fuse4fs_config_cache(struct fuse4fs *ff)
-{
- char buf[128];
- errcode_t err;
-
- snprintf(buf, sizeof(buf), "cache_blocks=%llu",
- FUSE4FS_B_TO_FSBT(ff, ff->cache_size));
- err = io_channel_set_options(ff->fs->io, buf);
- if (err) {
- err_printf(ff, "%s %lluk: %s\n",
- _("cannot set disk cache size to"),
- ff->cache_size >> 10,
- error_message(err));
- return err;
- }
-
- return 0;
-}
-
static errcode_t fuse4fs_check_support(struct fuse4fs *ff)
{
ext2_filsys fs = ff->fs;
@@ -7113,7 +7094,6 @@ enum {
FUSE4FS_VERSION,
FUSE4FS_HELP,
FUSE4FS_HELPFULL,
- FUSE4FS_CACHE_SIZE,
FUSE4FS_DIRSYNC,
FUSE4FS_ERRORS_BEHAVIOR,
#ifdef HAVE_FUSE_IOMAP
@@ -7163,7 +7143,6 @@ static struct fuse_opt fuse4fs_opts[] = {
FUSE_OPT_KEY("user_xattr", FUSE4FS_IGNORED),
FUSE_OPT_KEY("noblock_validity", FUSE4FS_IGNORED),
FUSE_OPT_KEY("nodelalloc", FUSE4FS_IGNORED),
- FUSE_OPT_KEY("cache_size=%s", FUSE4FS_CACHE_SIZE),
FUSE_OPT_KEY("dirsync", FUSE4FS_DIRSYNC),
FUSE_OPT_KEY("errors=%s", FUSE4FS_ERRORS_BEHAVIOR),
#ifdef HAVE_FUSE_IOMAP
@@ -7202,16 +7181,6 @@ static int fuse4fs_opt_proc(void *data, const char *arg,
return 0;
}
return 1;
- case FUSE4FS_CACHE_SIZE:
- ff->cache_size = parse_num_blocks2(arg + 11, -1);
- if (ff->cache_size < 1 || ff->cache_size > INT32_MAX) {
- fprintf(stderr, "%s: %s\n", arg,
- _("cache size must be between 1 block and 2GB."));
- return -1;
- }
-
- /* do not pass through to libfuse */
- return 0;
case FUSE4FS_ERRORS_BEHAVIOR:
if (strcmp(arg + 7, "continue") == 0)
ff->errors_behavior = EXT2_ERRORS_CONTINUE;
@@ -7268,7 +7237,6 @@ static int fuse4fs_opt_proc(void *data, const char *arg,
" -o kernel run this as if it were the kernel, which sets:\n"
" allow_others,default_permissions,suid,dev\n"
" -o directio use O_DIRECT to read and write the disk\n"
- " -o cache_size=N[KMG] use a disk cache of this size\n"
" -o errors= behavior when an error is encountered:\n"
" continue|remount-ro|panic\n"
#ifdef HAVE_FUSE_IOMAP
@@ -7311,28 +7279,6 @@ static const char *get_subtype(const char *argv0)
return "ext4";
}

-/* Figure out a reasonable default size for the disk cache */
-static unsigned long long default_cache_size(void)
-{
- long pages = 0, pagesize = 0;
- unsigned long long max_cache;
- unsigned long long ret = 32ULL << 20; /* 32 MB */
-
-#ifdef _SC_PHYS_PAGES
- pages = sysconf(_SC_PHYS_PAGES);
-#endif
-#ifdef _SC_PAGESIZE
- pagesize = sysconf(_SC_PAGESIZE);
-#endif
- if (pages > 0 && pagesize > 0) {
- max_cache = (unsigned long long)pagesize * pages / 20;
-
- if (max_cache > 0 && ret > max_cache)
- ret = max_cache;
- }
- return ret;
-}
-
#ifdef HAVE_FUSE_IOMAP
static inline bool fuse4fs_discover_iomap(struct fuse4fs *ff)
{
@@ -7554,6 +7500,7 @@ int main(int argc, char *argv[])
fctx.alloc_all_blocks = 1;
}

+ iocache_set_backing_manager(unix_io_manager);
err = fuse4fs_open(&fctx, EXT2_FLAG_EXCLUSIVE);
if (err) {
ret = 32;
@@ -7603,16 +7550,6 @@ int main(int argc, char *argv[])
fctx.translate_inums = 0;
}

- if (!fctx.cache_size)
- fctx.cache_size = default_cache_size();
- if (fctx.cache_size) {
- err = fuse4fs_config_cache(&fctx);
- if (err) {
- ret = 32;
- goto out;
- }
- }
-
err = fuse4fs_check_support(&fctx);
if (err) {
ret = 32;