fuse: allow fine grained attr cache invaldation

This patch adds the infrastructure for more fine grained attribute
invalidation.  Currently only 'atime' is invalidated separately.

The use of this infrastructure is extended to the statx(2) interface, which
for now means that if only 'atime' is invalid and STATX_ATIME is not
specified in the mask argument, then no GETATTR request will be generated.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index d1b2f42d746e9fa6710f67e21586001edae35d9a..2b6fc2b35649a153305ac7939b54472778ff2e3f 100644 (file)
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -81,13 +81,18 @@ u64 entry_attr_timeout(struct fuse_entry_out *o)
        return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
 }
 
+static void fuse_invalidate_attr_mask(struct inode *inode, u32 mask)
+{
+       set_mask_bits(&get_fuse_inode(inode)->inval_mask, 0, mask);
+}
+
 /*
  * Mark the attributes as stale, so that at the next call to
  * ->getattr() they will be fetched from userspace
  */
 void fuse_invalidate_attr(struct inode *inode)
 {
-       get_fuse_inode(inode)->i_time = 0;
+       fuse_invalidate_attr_mask(inode, STATX_BASIC_STATS);
 }
 
 static void fuse_dir_changed(struct inode *dir)
@@ -103,7 +108,7 @@ static void fuse_dir_changed(struct inode *dir)
 void fuse_invalidate_atime(struct inode *inode)
 {
        if (!IS_RDONLY(inode))
-               fuse_invalidate_attr(inode);
+               fuse_invalidate_attr_mask(inode, STATX_ATIME);
 }
 
 /*
@@ -917,7 +922,8 @@ static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
 }
 
 static int fuse_update_get_attr(struct inode *inode, struct file *file,
-                               struct kstat *stat, unsigned int flags)
+                               struct kstat *stat, u32 request_mask,
+                               unsigned int flags)
 {
        struct fuse_inode *fi = get_fuse_inode(inode);
        int err = 0;
@@ -927,6 +933,8 @@ static int fuse_update_get_attr(struct inode *inode, struct file *file,
                sync = true;
        else if (flags & AT_STATX_DONT_SYNC)
                sync = false;
+       else if (request_mask & READ_ONCE(fi->inval_mask))
+               sync = true;
        else
                sync = time_before64(fi->i_time, get_jiffies_64());
 
@@ -944,7 +952,7 @@ static int fuse_update_get_attr(struct inode *inode, struct file *file,
 
 int fuse_update_attributes(struct inode *inode, struct file *file)
 {
-       return fuse_update_get_attr(inode, file, NULL, 0);
+       return fuse_update_get_attr(inode, file, NULL, STATX_BASIC_STATS, 0);
 }
 
 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
@@ -1566,7 +1574,7 @@ static int fuse_getattr(const struct path *path, struct kstat *stat,
        if (!fuse_allow_current_process(fc))
                return -EACCES;
 
-       return fuse_update_get_attr(inode, NULL, stat, flags);
+       return fuse_update_get_attr(inode, NULL, stat, request_mask, flags);
 }
 
 static const struct inode_operations fuse_dir_inode_operations = {

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index b7d96e7b5e0f51114161a0868e2b25ae70e67a0f..0e32524e66bb2d80e4efb0ed9d2d4045be2b1280 100644 (file)
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -80,6 +80,9 @@ struct fuse_inode {
        /** Time in jiffies until the file attributes are valid */
        u64 i_time;
 
+       /* Which attributes are invalid */
+       u32 inval_mask;
+
        /** The sticky bit in inode->i_mode may have been removed, so
            preserve the original mode */
        umode_t orig_i_mode;

diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 8cebf4d5f51b3cc2af62716a36be4a00b52d2ce2..d5f845aefbc92c470094c5b25a5981822a849de2 100644 (file)
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -90,6 +90,7 @@ static struct inode *fuse_alloc_inode(struct super_block *sb)
 
        fi = get_fuse_inode(inode);
        fi->i_time = 0;
+       fi->inval_mask = 0;
        fi->nodeid = 0;
        fi->nlookup = 0;
        fi->attr_version = 0;
@@ -164,6 +165,7 @@ void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 
        fi->attr_version = ++fc->attr_version;
        fi->i_time = attr_valid;
+       WRITE_ONCE(fi->inval_mask, 0);
 
        inode->i_ino     = fuse_squash_ino(attr->ino);
        inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);