The branch main has been updated by asomers:
URL:
https://cgit.FreeBSD.org/src/commit/?id=5d94aaacb5180798b2f698e33937f068386004eb
commit 5d94aaacb5180798b2f698e33937f068386004eb
Author: Alan Somers <asom...@freebsd.org>
AuthorDate: 2021-10-03 16:59:04 +0000
Commit: Alan Somers <asom...@freebsd.org>
CommitDate: 2021-10-06 20:07:33 +0000
fusefs: quiet some cache-related warnings
If the FUSE server does something that would make our cache incoherent,
we should print a warning to the user. However, we previously warned in
some situations when we shouldn't, such as if the file's size changed on
the server _after_ our own attribute cache had expired. This change
suppresses the warning in cases like that. It also moves the warning
logic to a single place within the code.
PR: 256936
Reported by: Agata <chog...@moosefs.pro>
Tested by: Agata <chog...@moosefs.pro>, jsml4thwwbid6...@protonmail.com
MFC after: 2 weeks
---
sys/fs/fuse/fuse_internal.c | 74 +++++++++++++++++++++++++++++++--------------
sys/fs/fuse/fuse_internal.h | 3 +-
sys/fs/fuse/fuse_io.c | 4 +--
sys/fs/fuse/fuse_node.c | 19 ++++++++++--
sys/fs/fuse/fuse_node.h | 2 +-
sys/fs/fuse/fuse_vfsops.c | 40 +-----------------------
sys/fs/fuse/fuse_vnops.c | 41 ++-----------------------
7 files changed, 76 insertions(+), 107 deletions(-)
diff --git a/sys/fs/fuse/fuse_internal.c b/sys/fs/fuse/fuse_internal.c
index c52f12d3a71a..ffa4a40095b2 100644
--- a/sys/fs/fuse/fuse_internal.c
+++ b/sys/fs/fuse/fuse_internal.c
@@ -255,7 +255,8 @@ fuse_internal_access(struct vnode *vp,
*/
void
fuse_internal_cache_attrs(struct vnode *vp, struct fuse_attr *attr,
- uint64_t attr_valid, uint32_t attr_valid_nsec, struct vattr *vap)
+ uint64_t attr_valid, uint32_t attr_valid_nsec, struct vattr *vap,
+ bool from_server)
{
struct mount *mp;
struct fuse_vnode_data *fvdat;
@@ -271,9 +272,54 @@ fuse_internal_cache_attrs(struct vnode *vp, struct
fuse_attr *attr,
fuse_validity_2_bintime(attr_valid, attr_valid_nsec,
&fvdat->attr_cache_timeout);
+ if (vnode_isreg(vp) &&
+ fvdat->cached_attrs.va_size != VNOVAL &&
+ attr->size != fvdat->cached_attrs.va_size)
+ {
+ if ( data->cache_mode == FUSE_CACHE_WB &&
+ fvdat->flag & FN_SIZECHANGE)
+ {
+ const char *msg;
+
+ /*
+ * The server changed the file's size even though we're
+ * using writeback cacheing and and we have outstanding
+ * dirty writes! That's a server bug.
+ */
+ if (fuse_libabi_geq(data, 7, 23)) {
+ msg = "writeback cache incoherent!."
+ "To prevent data corruption, disable "
+ "the writeback cache according to your "
+ "FUSE server's documentation.";
+ } else {
+ msg = "writeback cache incoherent!."
+ "To prevent data corruption, disable "
+ "the writeback cache by setting "
+ "vfs.fusefs.data_cache_mode to 0 or 1.";
+ }
+ fuse_warn(data, FSESS_WARN_WB_CACHE_INCOHERENT, msg);
+ }
+ if (fuse_vnode_attr_cache_valid(vp) &&
+ data->cache_mode != FUSE_CACHE_UC)
+ {
+ /*
+ * The server changed the file's size even though we
+ * have it cached and our cache has not yet expired.
+ * That's a bug.
+ */
+ fuse_warn(data, FSESS_WARN_CACHE_INCOHERENT,
+ "cache incoherent! "
+ "To prevent "
+ "data corruption, disable the data cache "
+ "by mounting with -o direct_io, or as "
+ "directed otherwise by your FUSE server's "
+ "documentation.");
+ }
+ }
+
/* Fix our buffers if the filesize changed without us knowing */
if (vnode_isreg(vp) && attr->size != fvdat->cached_attrs.va_size) {
- (void)fuse_vnode_setsize(vp, attr->size);
+ (void)fuse_vnode_setsize(vp, attr->size, from_server);
fvdat->cached_attrs.va_size = attr->size;
}
@@ -806,7 +852,7 @@ fuse_internal_newentry_core(struct vnode *dvp,
fuse_vnode_clear_attr_cache(dvp);
fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid,
- feo->attr_valid_nsec, NULL);
+ feo->attr_valid_nsec, NULL, true);
return err;
}
@@ -912,26 +958,8 @@ fuse_internal_do_getattr(struct vnode *vp, struct vattr
*vap,
fao->attr.mtime = old_mtime.tv_sec;
fao->attr.mtimensec = old_mtime.tv_nsec;
}
- if (vnode_isreg(vp) &&
- fvdat->cached_attrs.va_size != VNOVAL &&
- fao->attr.size != fvdat->cached_attrs.va_size) {
- /*
- * The server changed the file's size even though we had it
- * cached! That's a server bug.
- */
- struct mount *mp = vnode_mount(vp);
- struct fuse_data *data = fuse_get_mpdata(mp);
-
- fuse_warn(data, FSESS_WARN_CACHE_INCOHERENT,
- "cache incoherent! "
- "To prevent data corruption, disable the data cache "
- "by mounting with -o direct_io, or as directed "
- "otherwise by your FUSE server's documentation.");
- int iosize = fuse_iosize(vp);
- v_inval_buf_range(vp, 0, INT64_MAX, iosize);
- }
fuse_internal_cache_attrs(vp, &fao->attr, fao->attr_valid,
- fao->attr_valid_nsec, vap);
+ fao->attr_valid_nsec, vap, true);
if (vtyp != vnode_vtype(vp)) {
fuse_internal_vnode_disappear(vp);
err = ENOENT;
@@ -1231,7 +1259,7 @@ int fuse_internal_setattr(struct vnode *vp, struct vattr
*vap,
struct fuse_attr_out *fao = (struct fuse_attr_out*)fdi.answ;
fuse_vnode_undirty_cached_timestamps(vp);
fuse_internal_cache_attrs(vp, &fao->attr, fao->attr_valid,
- fao->attr_valid_nsec, NULL);
+ fao->attr_valid_nsec, NULL, false);
}
out:
diff --git a/sys/fs/fuse/fuse_internal.h b/sys/fs/fuse/fuse_internal.h
index 20a10d7dfda0..e9fa3857227a 100644
--- a/sys/fs/fuse/fuse_internal.h
+++ b/sys/fs/fuse/fuse_internal.h
@@ -223,7 +223,8 @@ int fuse_internal_access(struct vnode *vp, accmode_t mode,
/* attributes */
void fuse_internal_cache_attrs(struct vnode *vp, struct fuse_attr *attr,
- uint64_t attr_valid, uint32_t attr_valid_nsec, struct vattr *vap);
+ uint64_t attr_valid, uint32_t attr_valid_nsec, struct vattr *vap,
+ bool from_server);
/* fsync */
diff --git a/sys/fs/fuse/fuse_io.c b/sys/fs/fuse/fuse_io.c
index 47c7fb97e556..637c36424d3f 100644
--- a/sys/fs/fuse/fuse_io.c
+++ b/sys/fs/fuse/fuse_io.c
@@ -571,7 +571,7 @@ retry:
as_written_offset = uio->uio_offset - diff;
if (as_written_offset - diff > filesize)
- fuse_vnode_setsize(vp, as_written_offset);
+ fuse_vnode_setsize(vp, as_written_offset, false);
if (as_written_offset - diff >= filesize)
fvdat->flag &= ~FN_SIZECHANGE;
@@ -715,7 +715,7 @@ again:
* Extend file _after_ locking buffer so we won't race
* with other readers
*/
- err = fuse_vnode_setsize(vp, uio->uio_offset + n);
+ err = fuse_vnode_setsize(vp, uio->uio_offset + n,
false);
filesize = uio->uio_offset + n;
fvdat->flag |= FN_SIZECHANGE;
if (err) {
diff --git a/sys/fs/fuse/fuse_node.c b/sys/fs/fuse/fuse_node.c
index 6acd1df29361..c296a3b3c330 100644
--- a/sys/fs/fuse/fuse_node.c
+++ b/sys/fs/fuse/fuse_node.c
@@ -389,11 +389,14 @@ fuse_vnode_savesize(struct vnode *vp, struct ucred *cred,
pid_t pid)
}
/*
- * Adjust the vnode's size to a new value, such as that provided by
- * FUSE_GETATTR.
+ * Adjust the vnode's size to a new value.
+ *
+ * If the new value came from the server, such as from a FUSE_GETATTR
+ * operation, set `from_server` true. But if it came from a local operation,
+ * such as write(2) or truncate(2), set `from_server` false.
*/
int
-fuse_vnode_setsize(struct vnode *vp, off_t newsize)
+fuse_vnode_setsize(struct vnode *vp, off_t newsize, bool from_server)
{
struct fuse_vnode_data *fvdat = VTOFUD(vp);
struct vattr *attrs;
@@ -434,6 +437,16 @@ fuse_vnode_setsize(struct vnode *vp, off_t newsize)
MPASS(bp->b_flags & B_VMIO);
vfs_bio_clrbuf(bp);
bp->b_dirtyend = MIN(bp->b_dirtyend, newsize - lbn * iosize);
+ } else if (from_server && newsize > oldsize && oldsize != VNOVAL) {
+ /*
+ * The FUSE server changed the file size behind our back. We
+ * should invalidate the entire cache.
+ */
+ daddr_t left_lbn, end_lbn;
+
+ left_lbn = oldsize / iosize;
+ end_lbn = howmany(newsize, iosize);
+ v_inval_buf_range(vp, 0, end_lbn, iosize);
}
out:
if (bp)
diff --git a/sys/fs/fuse/fuse_node.h b/sys/fs/fuse/fuse_node.h
index e5fb13d43bec..dcf5e4047778 100644
--- a/sys/fs/fuse/fuse_node.h
+++ b/sys/fs/fuse/fuse_node.h
@@ -201,7 +201,7 @@ void fuse_vnode_open(struct vnode *vp, int32_t
fuse_open_flags,
int fuse_vnode_savesize(struct vnode *vp, struct ucred *cred, pid_t pid);
-int fuse_vnode_setsize(struct vnode *vp, off_t newsize);
+int fuse_vnode_setsize(struct vnode *vp, off_t newsize, bool from_server);
void fuse_vnode_undirty_cached_timestamps(struct vnode *vp);
diff --git a/sys/fs/fuse/fuse_vfsops.c b/sys/fs/fuse/fuse_vfsops.c
index b188996066d5..3d5e168bcde2 100644
--- a/sys/fs/fuse/fuse_vfsops.c
+++ b/sys/fs/fuse/fuse_vfsops.c
@@ -539,7 +539,6 @@ fuse_vfsop_vget(struct mount *mp, ino_t ino, int flags,
struct vnode **vpp)
struct fuse_entry_out *feo;
struct fuse_vnode_data *fvdat;
const char dot[] = ".";
- off_t filesize;
enum vtype vtyp;
int error;
@@ -576,47 +575,10 @@ fuse_vfsop_vget(struct mount *mp, ino_t ino, int flags,
struct vnode **vpp)
error = fuse_vnode_get(mp, feo, nodeid, NULL, vpp, NULL, vtyp);
if (error)
goto out;
- filesize = feo->attr.size;
-
- /*
- * In the case where we are looking up a FUSE node represented by an
- * existing cached vnode, and the true size reported by FUSE_LOOKUP
- * doesn't match the vnode's cached size, then any cached writes beyond
- * the file's current size are lost.
- *
- * We can get here:
- * * following attribute cache expiration, or
- * * due a bug in the daemon, or
- */
fvdat = VTOFUD(*vpp);
- if (vnode_isreg(*vpp) &&
- filesize != fvdat->cached_attrs.va_size &&
- fvdat->flag & FN_SIZECHANGE) {
- if (data->cache_mode == fuse_data_cache_mode) {
- const char *msg;
-
- if (fuse_libabi_geq(data, 7, 23)) {
- msg = "writeback cache incoherent!."
- "To prevent data corruption, disable "
- "the writeback cache according to your "
- "FUSE server's documentation.";
- } else {
- msg = "writeback cache incoherent!."
- "To prevent data corruption, disable "
- "the writeback cache by setting "
- "vfs.fusefs.data_cache_mode to 0 or 1.";
- }
- fuse_warn(data, FSESS_WARN_WB_CACHE_INCOHERENT, msg);
- } else {
- /* If we get here, it's likely a fusefs kernel bug */
- printf("%s: WB cache incoherent on %s!\n", __func__,
- vnode_mount(*vpp)->mnt_stat.f_mntonname);
- }
- fvdat->flag &= ~FN_SIZECHANGE;
- }
fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid,
- feo->attr_valid_nsec, NULL);
+ feo->attr_valid_nsec, NULL, true);
fuse_validity_2_bintime(feo->entry_valid, feo->entry_valid_nsec,
&fvdat->entry_cache_timeout);
out:
diff --git a/sys/fs/fuse/fuse_vnops.c b/sys/fs/fuse/fuse_vnops.c
index 4c8c8c1d4461..dd8ff0fcc45a 100644
--- a/sys/fs/fuse/fuse_vnops.c
+++ b/sys/fs/fuse/fuse_vnops.c
@@ -895,7 +895,7 @@ fuse_vnop_create(struct vop_create_args *ap)
}
ASSERT_VOP_ELOCKED(*vpp, "fuse_vnop_create");
fuse_internal_cache_attrs(*vpp, &feo->attr, feo->attr_valid,
- feo->attr_valid_nsec, NULL);
+ feo->attr_valid_nsec, NULL, true);
fuse_filehandle_init(*vpp, FUFH_RDWR, NULL, td, cred, foo);
fuse_vnode_open(*vpp, foo->open_flags, td);
@@ -1151,7 +1151,7 @@ fuse_vnop_link(struct vop_link_args *ap)
*/
fuse_vnode_clear_attr_cache(tdvp);
fuse_internal_cache_attrs(vp, &feo->attr, feo->attr_valid,
- feo->attr_valid_nsec, NULL);
+ feo->attr_valid_nsec, NULL, true);
}
out:
fdisp_destroy(&fdi);
@@ -1360,52 +1360,17 @@ fuse_vnop_lookup(struct vop_lookup_args *ap)
*vpp = dvp;
} else {
struct fuse_vnode_data *fvdat;
- struct vattr *vap;
err = fuse_vnode_get(vnode_mount(dvp), feo, nid, dvp,
&vp, cnp, vtyp);
if (err)
goto out;
*vpp = vp;
-
- /*
- * In the case where we are looking up a FUSE node
- * represented by an existing cached vnode, and the
- * true size reported by FUSE_LOOKUP doesn't match
- * the vnode's cached size, then any cached writes
- * beyond the file's current size are lost.
- *
- * We can get here:
- * * following attribute cache expiration, or
- * * due a bug in the daemon, or
- */
fvdat = VTOFUD(vp);
- if (vnode_isreg(vp) &&
- ((filesize != fvdat->cached_attrs.va_size &&
- fvdat->flag & FN_SIZECHANGE) ||
- ((vap = VTOVA(vp)) &&
- filesize != vap->va_size)))
- {
- fvdat->flag &= ~FN_SIZECHANGE;
- /*
- * The server changed the file's size even
- * though we had it cached, or had dirty writes
- * in the WB cache!
- */
- fuse_warn(data, FSESS_WARN_CACHE_INCOHERENT,
- "cache incoherent! "
- "To prevent "
- "data corruption, disable the data cache "
- "by mounting with -o direct_io, or as "
- "directed otherwise by your FUSE server's "
- "documentation.");
- int iosize = fuse_iosize(vp);
- v_inval_buf_range(vp, 0, INT64_MAX, iosize);
- }
MPASS(feo != NULL);
fuse_internal_cache_attrs(*vpp, &feo->attr,
- feo->attr_valid, feo->attr_valid_nsec, NULL);
+ feo->attr_valid, feo->attr_valid_nsec, NULL,
true);
fuse_validity_2_bintime(feo->entry_valid,
feo->entry_valid_nsec,
&fvdat->entry_cache_timeout);
