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authornbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>2009-09-26 18:51:05 +0000
committernbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>2009-09-26 18:51:05 +0000
commitcf5d9b9638eaf513cdff5732a32cc4537f61ed56 (patch)
tree724772fe366de899c26eeaab13be83b7c7cb9d73
parentaeae9956b5fc91e84ac00d73a0d7e037251b4123 (diff)
add jffs2 whiteout support (necessary for using it with union mounts)
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@17745 3c298f89-4303-0410-b956-a3cf2f4a3e73
-rw-r--r--target/linux/generic-2.6/patches-2.6.31/233-jffs2_whiteout_support.patch186
1 files changed, 186 insertions, 0 deletions
diff --git a/target/linux/generic-2.6/patches-2.6.31/233-jffs2_whiteout_support.patch b/target/linux/generic-2.6/patches-2.6.31/233-jffs2_whiteout_support.patch
new file mode 100644
index 0000000000..72a428237b
--- /dev/null
+++ b/target/linux/generic-2.6/patches-2.6.31/233-jffs2_whiteout_support.patch
@@ -0,0 +1,186 @@
+--- a/fs/jffs2/dir.c
++++ b/fs/jffs2/dir.c
+@@ -34,6 +34,9 @@
+ static int jffs2_rename (struct inode *, struct dentry *,
+ struct inode *, struct dentry *);
+
++static int jffs2_whiteout (struct inode *, struct dentry *, struct dentry *);
++static int jffs2_fallthru (struct inode *, struct dentry *);
++
+ const struct file_operations jffs2_dir_operations =
+ {
+ .read = generic_read_dir,
+@@ -55,6 +58,8 @@
+ .rmdir = jffs2_rmdir,
+ .mknod = jffs2_mknod,
+ .rename = jffs2_rename,
++ .fallthru = jffs2_fallthru,
++ .whiteout = jffs2_whiteout,
+ .permission = jffs2_permission,
+ .setattr = jffs2_setattr,
+ .setxattr = jffs2_setxattr,
+@@ -98,8 +103,21 @@
+ fd = fd_list;
+ }
+ }
+- if (fd)
+- ino = fd->ino;
++ if (fd) {
++ spin_lock(&target->d_lock);
++ switch(fd->type) {
++ case DT_WHT:
++ target->d_flags |= DCACHE_WHITEOUT;
++ break;
++ case DT_UNKNOWN:
++ target->d_flags |= DCACHE_FALLTHRU;
++ break;
++ default:
++ ino = fd->ino;
++ break;
++ }
++ spin_unlock(&target->d_lock);
++ }
+ mutex_unlock(&dir_f->sem);
+ if (ino) {
+ inode = jffs2_iget(dir_i->i_sb, ino);
+@@ -155,7 +173,9 @@
+ fd->name, fd->ino, fd->type, curofs, offset));
+ continue;
+ }
+- if (!fd->ino) {
++ if (fd->type == DT_UNKNOWN)
++ fd->ino = 100; /* XXX: arbitrary */
++ else if (!fd->ino && (fd->type != DT_WHT)) {
+ D2(printk(KERN_DEBUG "Skipping deletion dirent \"%s\"\n", fd->name));
+ offset++;
+ continue;
+@@ -498,6 +518,11 @@
+ return PTR_ERR(inode);
+ }
+
++ if (dentry->d_flags & DCACHE_WHITEOUT) {
++ inode->i_flags |= S_OPAQUE;
++ ri->flags = cpu_to_je16(JFFS2_INO_FLAG_OPAQUE);
++ }
++
+ inode->i_op = &jffs2_dir_inode_operations;
+ inode->i_fop = &jffs2_dir_operations;
+
+@@ -779,6 +804,82 @@
+ return 0;
+ }
+
++static int jffs2_fallthru (struct inode *dir, struct dentry *dentry)
++{
++ struct jffs2_sb_info *c = JFFS2_SB_INFO(dir->i_sb);
++ uint32_t now;
++ int ret;
++
++ now = get_seconds();
++ ret = jffs2_do_link(c, JFFS2_INODE_INFO(dir), 0, DT_UNKNOWN,
++ dentry->d_name.name, dentry->d_name.len, now);
++ if (ret)
++ return ret;
++
++ d_instantiate(dentry, NULL);
++ spin_lock(&dentry->d_lock);
++ dentry->d_flags |= DCACHE_FALLTHRU;
++ spin_unlock(&dentry->d_lock);
++
++ return 0;
++}
++
++static int jffs2_whiteout (struct inode *dir, struct dentry *old_dentry,
++ struct dentry *new_dentry)
++{
++ struct jffs2_sb_info *c = JFFS2_SB_INFO(dir->i_sb);
++ struct jffs2_inode_info *victim_f = NULL;
++ uint32_t now;
++ int ret;
++
++ /* If it's a directory, then check whether it is really empty
++ */
++ if (new_dentry->d_inode) {
++ victim_f = JFFS2_INODE_INFO(old_dentry->d_inode);
++ if (S_ISDIR(old_dentry->d_inode->i_mode)) {
++ struct jffs2_full_dirent *fd;
++
++ mutex_lock(&victim_f->sem);
++ for (fd = victim_f->dents; fd; fd = fd->next) {
++ if (fd->ino) {
++ mutex_unlock(&victim_f->sem);
++ return -ENOTEMPTY;
++ }
++ }
++ mutex_unlock(&victim_f->sem);
++ }
++ }
++
++ now = get_seconds();
++ ret = jffs2_do_link(c, JFFS2_INODE_INFO(dir), 0, DT_WHT,
++ new_dentry->d_name.name, new_dentry->d_name.len, now);
++ if (ret)
++ return ret;
++
++ spin_lock(&new_dentry->d_lock);
++ new_dentry->d_flags &= ~DCACHE_FALLTHRU;
++ new_dentry->d_flags |= DCACHE_WHITEOUT;
++ spin_unlock(&new_dentry->d_lock);
++ d_add(new_dentry, NULL);
++
++ if (victim_f) {
++ /* There was a victim. Kill it off nicely */
++ drop_nlink(old_dentry->d_inode);
++ /* Don't oops if the victim was a dirent pointing to an
++ inode which didn't exist. */
++ if (victim_f->inocache) {
++ mutex_lock(&victim_f->sem);
++ if (S_ISDIR(old_dentry->d_inode->i_mode))
++ victim_f->inocache->pino_nlink = 0;
++ else
++ victim_f->inocache->pino_nlink--;
++ mutex_unlock(&victim_f->sem);
++ }
++ }
++
++ return 0;
++}
++
+ static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
+ struct inode *new_dir_i, struct dentry *new_dentry)
+ {
+--- a/fs/jffs2/fs.c
++++ b/fs/jffs2/fs.c
+@@ -301,6 +301,10 @@
+
+ inode->i_op = &jffs2_dir_inode_operations;
+ inode->i_fop = &jffs2_dir_operations;
++
++ if (je16_to_cpu(latest_node.flags) & JFFS2_INO_FLAG_OPAQUE)
++ inode->i_flags |= S_OPAQUE;
++
+ break;
+ }
+ case S_IFREG:
+--- a/fs/jffs2/super.c
++++ b/fs/jffs2/super.c
+@@ -172,7 +172,7 @@
+
+ sb->s_op = &jffs2_super_operations;
+ sb->s_export_op = &jffs2_export_ops;
+- sb->s_flags = sb->s_flags | MS_NOATIME;
++ sb->s_flags = sb->s_flags | MS_NOATIME | MS_WHITEOUT;
+ sb->s_xattr = jffs2_xattr_handlers;
+ #ifdef CONFIG_JFFS2_FS_POSIX_ACL
+ sb->s_flags |= MS_POSIXACL;
+--- a/include/linux/jffs2.h
++++ b/include/linux/jffs2.h
+@@ -87,6 +87,8 @@
+ #define JFFS2_INO_FLAG_USERCOMPR 2 /* User has requested a specific
+ compression type */
+
++#define JFFS2_INO_FLAG_OPAQUE 4 /* Directory is opaque (for union mounts) */
++
+
+ /* These can go once we've made sure we've caught all uses without
+ byteswapping */