[PATCH v2 4/4] fuse: support changing per-file DAX flag inside guest
flat view
STALE1910d
From: Jeffle Xu <hidden>
Date: 2021-07-16 10:48:01
Also in:
linux-fsdevel
Subsystem:
filesystems (vfs and infrastructure), fuse filesystem [core], the rest · Maintainers:
Alexander Viro, Christian Brauner, Miklos Szeredi, Linus Torvalds
Fuse client can enable or disable per-file DAX inside guest by chattr(1). Similarly the new state won't be updated until the file is closed and reopened later. It is worth nothing that it is a best-effort style, since whether per-file DAX is enabled or not is controlled by fuse_attr.flags retrieved by FUSE LOOKUP routine, while the algorithm constructing fuse_attr.flags is totally fuse server specific, not to mention ioctl may not be supported by fuse server at all. Signed-off-by: Jeffle Xu <redacted> --- fs/fuse/ioctl.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/fs/fuse/ioctl.c b/fs/fuse/ioctl.c
index 546ea3d58fb4..172e05c3f038 100644
--- a/fs/fuse/ioctl.c
+++ b/fs/fuse/ioctl.c@@ -460,6 +460,7 @@ int fuse_fileattr_set(struct user_namespace *mnt_userns, struct fuse_file *ff; unsigned int flags = fa->flags; struct fsxattr xfa; + bool newdax; int err; ff = fuse_priv_ioctl_prepare(inode);
@@ -467,10 +468,9 @@ int fuse_fileattr_set(struct user_namespace *mnt_userns, return PTR_ERR(ff); if (fa->flags_valid) { + newdax = flags & FS_DAX_FL; err = fuse_priv_ioctl(inode, ff, FS_IOC_SETFLAGS, &flags, sizeof(flags)); - if (err) - goto cleanup; } else { memset(&xfa, 0, sizeof(xfa)); xfa.fsx_xflags = fa->fsx_xflags;
@@ -479,11 +479,14 @@ int fuse_fileattr_set(struct user_namespace *mnt_userns, xfa.fsx_projid = fa->fsx_projid; xfa.fsx_cowextsize = fa->fsx_cowextsize; + newdax = fa->fsx_xflags & FS_XFLAG_DAX; err = fuse_priv_ioctl(inode, ff, FS_IOC_FSSETXATTR, &xfa, sizeof(xfa)); } -cleanup: + if (!err && IS_ENABLED(CONFIG_FUSE_DAX)) + fuse_dax_dontcache(inode, newdax); + fuse_priv_ioctl_cleanup(inode, ff); return err;
--
2.27.0
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