X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Fshmem.c;h=4959535fc14c4a7aa3308bb316c4a13a3ba2baa3;hb=f2a2a7108aa0039ba7a5fe7a0d2ecef2219a7584;hp=b96de69f236b22225c4dcb9221d807808a7c8945;hpb=db1a19b38f3a85f475b4ad716c71be133d8ca48e;p=linux-2.6

diff --git a/mm/shmem.c b/mm/shmem.c
index b96de69f23..4959535fc1 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -48,6 +48,7 @@
 #include <linux/ctype.h>
 #include <linux/migrate.h>
 #include <linux/highmem.h>
+#include <linux/backing-dev.h>
 
 #include <asm/uaccess.h>
 #include <asm/div64.h>
@@ -1131,7 +1132,7 @@ repeat:
 			page_cache_release(swappage);
 			if (error == -ENOMEM) {
 				/* let kswapd refresh zone for GFP_ATOMICs */
-				blk_congestion_wait(WRITE, HZ/50);
+				congestion_wait(WRITE, HZ/50);
 			}
 			goto repeat;
 		}
@@ -1362,6 +1363,7 @@ shmem_get_inode(struct super_block *sb, int mode, dev_t dev)
 		inode->i_mapping->a_ops = &shmem_aops;
 		inode->i_mapping->backing_dev_info = &shmem_backing_dev_info;
 		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+		inode->i_generation = get_seconds();
 		info = SHMEM_I(inode);
 		memset(info, 0, (char *)inode - (char *)info);
 		spin_lock_init(&info->lock);
@@ -1379,7 +1381,7 @@ shmem_get_inode(struct super_block *sb, int mode, dev_t dev)
 							&sbinfo->policy_nodes);
 			break;
 		case S_IFDIR:
-			inode->i_nlink++;
+			inc_nlink(inode);
 			/* Some things misbehave if size == 0 on a directory */
 			inode->i_size = 2 * BOGO_DIRENT_SIZE;
 			inode->i_op = &shmem_dir_inode_operations;
@@ -1715,7 +1717,7 @@ static int shmem_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 
 	if ((error = shmem_mknod(dir, dentry, mode | S_IFDIR, 0)))
 		return error;
-	dir->i_nlink++;
+	inc_nlink(dir);
 	return 0;
 }
 
@@ -1750,7 +1752,7 @@ static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentr
 
 	dir->i_size += BOGO_DIRENT_SIZE;
 	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
-	inode->i_nlink++;
+	inc_nlink(inode);
 	atomic_inc(&inode->i_count);	/* New dentry reference */
 	dget(dentry);		/* Extra pinning count for the created dentry */
 	d_instantiate(dentry, inode);
@@ -1772,7 +1774,7 @@ static int shmem_unlink(struct inode *dir, struct dentry *dentry)
 
 	dir->i_size -= BOGO_DIRENT_SIZE;
 	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
-	inode->i_nlink--;
+	drop_nlink(inode);
 	dput(dentry);	/* Undo the count from "create" - this does all the work */
 	return 0;
 }
@@ -1782,8 +1784,8 @@ static int shmem_rmdir(struct inode *dir, struct dentry *dentry)
 	if (!simple_empty(dentry))
 		return -ENOTEMPTY;
 
-	dentry->d_inode->i_nlink--;
-	dir->i_nlink--;
+	drop_nlink(dentry->d_inode);
+	drop_nlink(dir);
 	return shmem_unlink(dir, dentry);
 }
 
@@ -1804,10 +1806,10 @@ static int shmem_rename(struct inode *old_dir, struct dentry *old_dentry, struct
 	if (new_dentry->d_inode) {
 		(void) shmem_unlink(new_dir, new_dentry);
 		if (they_are_dirs)
-			old_dir->i_nlink--;
+			drop_nlink(old_dir);
 	} else if (they_are_dirs) {
-		old_dir->i_nlink--;
-		new_dir->i_nlink++;
+		drop_nlink(old_dir);
+		inc_nlink(new_dir);
 	}
 
 	old_dir->i_size -= BOGO_DIRENT_SIZE;
@@ -1956,6 +1958,85 @@ static struct xattr_handler *shmem_xattr_handlers[] = {
 };
 #endif
 
+static struct dentry *shmem_get_parent(struct dentry *child)
+{
+	return ERR_PTR(-ESTALE);
+}
+
+static int shmem_match(struct inode *ino, void *vfh)
+{
+	__u32 *fh = vfh;
+	__u64 inum = fh[2];
+	inum = (inum << 32) | fh[1];
+	return ino->i_ino == inum && fh[0] == ino->i_generation;
+}
+
+static struct dentry *shmem_get_dentry(struct super_block *sb, void *vfh)
+{
+	struct dentry *de = NULL;
+	struct inode *inode;
+	__u32 *fh = vfh;
+	__u64 inum = fh[2];
+	inum = (inum << 32) | fh[1];
+
+	inode = ilookup5(sb, (unsigned long)(inum+fh[0]), shmem_match, vfh);
+	if (inode) {
+		de = d_find_alias(inode);
+		iput(inode);
+	}
+
+	return de? de: ERR_PTR(-ESTALE);
+}
+
+static struct dentry *shmem_decode_fh(struct super_block *sb, __u32 *fh,
+		int len, int type,
+		int (*acceptable)(void *context, struct dentry *de),
+		void *context)
+{
+	if (len < 3)
+		return ERR_PTR(-ESTALE);
+
+	return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable,
+							context);
+}
+
+static int shmem_encode_fh(struct dentry *dentry, __u32 *fh, int *len,
+				int connectable)
+{
+	struct inode *inode = dentry->d_inode;
+
+	if (*len < 3)
+		return 255;
+
+	if (hlist_unhashed(&inode->i_hash)) {
+		/* Unfortunately insert_inode_hash is not idempotent,
+		 * so as we hash inodes here rather than at creation
+		 * time, we need a lock to ensure we only try
+		 * to do it once
+		 */
+		static DEFINE_SPINLOCK(lock);
+		spin_lock(&lock);
+		if (hlist_unhashed(&inode->i_hash))
+			__insert_inode_hash(inode,
+					    inode->i_ino + inode->i_generation);
+		spin_unlock(&lock);
+	}
+
+	fh[0] = inode->i_generation;
+	fh[1] = inode->i_ino;
+	fh[2] = ((__u64)inode->i_ino) >> 32;
+
+	*len = 3;
+	return 1;
+}
+
+static struct export_operations shmem_export_ops = {
+	.get_parent     = shmem_get_parent,
+	.get_dentry     = shmem_get_dentry,
+	.encode_fh      = shmem_encode_fh,
+	.decode_fh      = shmem_decode_fh,
+};
+
 static int shmem_parse_options(char *options, int *mode, uid_t *uid,
 	gid_t *gid, unsigned long *blocks, unsigned long *inodes,
 	int *policy, nodemask_t *policy_nodes)
@@ -2128,6 +2209,7 @@ static int shmem_fill_super(struct super_block *sb,
 					&inodes, &policy, &policy_nodes))
 			return -EINVAL;
 	}
+	sb->s_export_op = &shmem_export_ops;
 #else
 	sb->s_flags |= MS_NOUSER;
 #endif