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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /fs/coda/cnode.c
Initial import
Diffstat (limited to 'fs/coda/cnode.c')
-rw-r--r--fs/coda/cnode.c168
1 files changed, 168 insertions, 0 deletions
diff --git a/fs/coda/cnode.c b/fs/coda/cnode.c
new file mode 100644
index 000000000..7740b1c87
--- /dev/null
+++ b/fs/coda/cnode.c
@@ -0,0 +1,168 @@
+/* cnode related routines for the coda kernel code
+ (C) 1996 Peter Braam
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/time.h>
+
+#include <linux/coda.h>
+#include <linux/coda_psdev.h>
+#include "coda_linux.h"
+
+static inline int coda_fideq(struct CodaFid *fid1, struct CodaFid *fid2)
+{
+ return memcmp(fid1, fid2, sizeof(*fid1)) == 0;
+}
+
+static const struct inode_operations coda_symlink_inode_operations = {
+ .readlink = generic_readlink,
+ .follow_link = page_follow_link_light,
+ .put_link = page_put_link,
+ .setattr = coda_setattr,
+};
+
+/* cnode.c */
+static void coda_fill_inode(struct inode *inode, struct coda_vattr *attr)
+{
+ coda_vattr_to_iattr(inode, attr);
+
+ if (S_ISREG(inode->i_mode)) {
+ inode->i_op = &coda_file_inode_operations;
+ inode->i_fop = &coda_file_operations;
+ } else if (S_ISDIR(inode->i_mode)) {
+ inode->i_op = &coda_dir_inode_operations;
+ inode->i_fop = &coda_dir_operations;
+ } else if (S_ISLNK(inode->i_mode)) {
+ inode->i_op = &coda_symlink_inode_operations;
+ inode->i_data.a_ops = &coda_symlink_aops;
+ inode->i_mapping = &inode->i_data;
+ } else
+ init_special_inode(inode, inode->i_mode, huge_decode_dev(attr->va_rdev));
+}
+
+static int coda_test_inode(struct inode *inode, void *data)
+{
+ struct CodaFid *fid = (struct CodaFid *)data;
+ struct coda_inode_info *cii = ITOC(inode);
+ return coda_fideq(&cii->c_fid, fid);
+}
+
+static int coda_set_inode(struct inode *inode, void *data)
+{
+ struct CodaFid *fid = (struct CodaFid *)data;
+ struct coda_inode_info *cii = ITOC(inode);
+ cii->c_fid = *fid;
+ return 0;
+}
+
+struct inode * coda_iget(struct super_block * sb, struct CodaFid * fid,
+ struct coda_vattr * attr)
+{
+ struct inode *inode;
+ struct coda_inode_info *cii;
+ unsigned long hash = coda_f2i(fid);
+
+ inode = iget5_locked(sb, hash, coda_test_inode, coda_set_inode, fid);
+
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ if (inode->i_state & I_NEW) {
+ cii = ITOC(inode);
+ /* we still need to set i_ino for things like stat(2) */
+ inode->i_ino = hash;
+ /* inode is locked and unique, no need to grab cii->c_lock */
+ cii->c_mapcount = 0;
+ unlock_new_inode(inode);
+ }
+
+ /* always replace the attributes, type might have changed */
+ coda_fill_inode(inode, attr);
+ return inode;
+}
+
+/* this is effectively coda_iget:
+ - get attributes (might be cached)
+ - get the inode for the fid using vfs iget
+ - link the two up if this is needed
+ - fill in the attributes
+*/
+struct inode *coda_cnode_make(struct CodaFid *fid, struct super_block *sb)
+{
+ struct coda_vattr attr;
+ struct inode *inode;
+ int error;
+
+ /* We get inode numbers from Venus -- see venus source */
+ error = venus_getattr(sb, fid, &attr);
+ if (error)
+ return ERR_PTR(error);
+
+ inode = coda_iget(sb, fid, &attr);
+ if (IS_ERR(inode))
+ pr_warn("%s: coda_iget failed\n", __func__);
+ return inode;
+}
+
+
+/* Although we treat Coda file identifiers as immutable, there is one
+ * special case for files created during a disconnection where they may
+ * not be globally unique. When an identifier collision is detected we
+ * first try to flush the cached inode from the kernel and finally
+ * resort to renaming/rehashing in-place. Userspace remembers both old
+ * and new values of the identifier to handle any in-flight upcalls.
+ * The real solution is to use globally unique UUIDs as identifiers, but
+ * retrofitting the existing userspace code for this is non-trivial. */
+void coda_replace_fid(struct inode *inode, struct CodaFid *oldfid,
+ struct CodaFid *newfid)
+{
+ struct coda_inode_info *cii = ITOC(inode);
+ unsigned long hash = coda_f2i(newfid);
+
+ BUG_ON(!coda_fideq(&cii->c_fid, oldfid));
+
+ /* replace fid and rehash inode */
+ /* XXX we probably need to hold some lock here! */
+ remove_inode_hash(inode);
+ cii->c_fid = *newfid;
+ inode->i_ino = hash;
+ __insert_inode_hash(inode, hash);
+}
+
+/* convert a fid to an inode. */
+struct inode *coda_fid_to_inode(struct CodaFid *fid, struct super_block *sb)
+{
+ struct inode *inode;
+ unsigned long hash = coda_f2i(fid);
+
+ if ( !sb ) {
+ pr_warn("%s: no sb!\n", __func__);
+ return NULL;
+ }
+
+ inode = ilookup5(sb, hash, coda_test_inode, fid);
+ if ( !inode )
+ return NULL;
+
+ /* we should never see newly created inodes because we intentionally
+ * fail in the initialization callback */
+ BUG_ON(inode->i_state & I_NEW);
+
+ return inode;
+}
+
+/* the CONTROL inode is made without asking attributes from Venus */
+struct inode *coda_cnode_makectl(struct super_block *sb)
+{
+ struct inode *inode = new_inode(sb);
+ if (inode) {
+ inode->i_ino = CTL_INO;
+ inode->i_op = &coda_ioctl_inode_operations;
+ inode->i_fop = &coda_ioctl_operations;
+ inode->i_mode = 0444;
+ return inode;
+ }
+ return ERR_PTR(-ENOMEM);
+}
+