fuse: reduce size of struct fuse_inode

Do this by grouping fields used for cached writes and putting them into a
union with fileds used for cached readdir (with obviously no overlap, since
we don't have hybrid objects).

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

4 files changed, 58 insertions, 41 deletions

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 6800fdc3e730..d1b2f42d746e 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1414,8 +1414,11 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
                 file = NULL;
         }
 
-        if (attr->ia_valid & ATTR_SIZE)
+        if (attr->ia_valid & ATTR_SIZE) {
+                if (WARN_ON(!S_ISREG(inode->i_mode)))
+                        return -EIO;
                 is_truncate = true;
+        }
 
         if (is_truncate) {
                 fuse_set_nowrite(inode);
@@ -1619,8 +1622,16 @@ void fuse_init_common(struct inode *inode)
 
 void fuse_init_dir(struct inode *inode)
 {
+        struct fuse_inode *fi = get_fuse_inode(inode);
+
         inode->i_op = &fuse_dir_inode_operations;
         inode->i_fop = &fuse_dir_operations;
+
+        spin_lock_init(&fi->rdc.lock);
+        fi->rdc.cached = false;
+        fi->rdc.size = 0;
+        fi->rdc.pos = 0;
+        fi->rdc.version = 0;
 }
 
 void fuse_init_symlink(struct inode *inode)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index e10c0443c56f..b10d14baeb1f 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -3143,6 +3143,14 @@ static const struct address_space_operations fuse_file_aops  = {
 
 void fuse_init_file_inode(struct inode *inode)
 {
+        struct fuse_inode *fi = get_fuse_inode(inode);
+
         inode->i_fop = &fuse_file_operations;
         inode->i_data.a_ops = &fuse_file_aops;
+
+        INIT_LIST_HEAD(&fi->write_files);
+        INIT_LIST_HEAD(&fi->queued_writes);
+        fi->writectr = 0;
+        init_waitqueue_head(&fi->page_waitq);
+        INIT_LIST_HEAD(&fi->writepages);
 }
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index d9d1ea78efa6..f5bdce84e766 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -87,45 +87,51 @@ struct fuse_inode {
         /** Version of last attribute change */
         u64 attr_version;
 
-        /** Files usable in writepage.  Protected by fc->lock */
-        struct list_head write_files;
+        union {
+                /* Write related fields (regular file only) */
+                struct {
+                        /* Files usable in writepage.  Protected by fc->lock */
+                        struct list_head write_files;
 
-        /** Writepages pending on truncate or fsync */
-        struct list_head queued_writes;
+                        /* Writepages pending on truncate or fsync */
+                        struct list_head queued_writes;
 
-        /** Number of sent writes, a negative bias (FUSE_NOWRITE)
-         * means more writes are blocked */
-        int writectr;
+                        /* Number of sent writes, a negative bias
+                         * (FUSE_NOWRITE) means more writes are blocked */
+                        int writectr;
 
-        /** Waitq for writepage completion */
-        wait_queue_head_t page_waitq;
+                        /* Waitq for writepage completion */
+                        wait_queue_head_t page_waitq;
 
-        /** List of writepage requestst (pending or sent) */
-        struct list_head writepages;
+                        /* List of writepage requestst (pending or sent) */
+                        struct list_head writepages;
+                };
 
-        /* readdir cache */
-        struct {
-                /* true if fully cached */
-                bool cached;
+                /* readdir cache (directory only) */
+                struct {
+                        /* true if fully cached */
+                        bool cached;
 
-                /* size of cache */
-                loff_t size;
+                        /* size of cache */
+                        loff_t size;
 
-                /* position at end of cache (position of next entry) */
-                loff_t pos;
+                        /* position at end of cache (position of next entry) */
+                        loff_t pos;
 
-                /* version of the cache */
-                u64 version;
+                        /* version of the cache */
+                        u64 version;
 
-                /* modification time of directory when cache was started */
-                struct timespec64 mtime;
+                        /* modification time of directory when cache was
+                         * started */
+                        struct timespec64 mtime;
 
-                /* iversion of directory when cache was started */
-                u64 iversion;
+                        /* iversion of directory when cache was started */
+                        u64 iversion;
 
-                /* protects above fields */
-                spinlock_t lock;
-        } rdc;
+                        /* protects above fields */
+                        spinlock_t lock;
+                } rdc;
+        };
 
         /** Miscellaneous bits describing inode state */
         unsigned long state;
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index eef2ae713f75..82db1ab53420 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -93,18 +93,8 @@ static struct inode *fuse_alloc_inode(struct super_block *sb)
         fi->nodeid = 0;
         fi->nlookup = 0;
         fi->attr_version = 0;
-        fi->writectr = 0;
         fi->orig_ino = 0;
         fi->state = 0;
-        INIT_LIST_HEAD(&fi->write_files);
-        INIT_LIST_HEAD(&fi->queued_writes);
-        INIT_LIST_HEAD(&fi->writepages);
-        init_waitqueue_head(&fi->page_waitq);
-        spin_lock_init(&fi->rdc.lock);
-        fi->rdc.cached = false;
-        fi->rdc.size = 0;
-        fi->rdc.pos = 0;
-        fi->rdc.version = 0;
         mutex_init(&fi->mutex);
         fi->forget = fuse_alloc_forget();
         if (!fi->forget) {
@@ -124,8 +114,10 @@ static void fuse_i_callback(struct rcu_head *head)
 static void fuse_destroy_inode(struct inode *inode)
 {
         struct fuse_inode *fi = get_fuse_inode(inode);
-        BUG_ON(!list_empty(&fi->write_files));
-        BUG_ON(!list_empty(&fi->queued_writes));
+        if (S_ISREG(inode->i_mode)) {
+                WARN_ON(!list_empty(&fi->write_files));
+                WARN_ON(!list_empty(&fi->queued_writes));
+        }
         mutex_destroy(&fi->mutex);
         kfree(fi->forget);
         call_rcu(&inode->i_rcu, fuse_i_callback);