diff options
Diffstat (limited to 'kernel/fs/coda/cnode.c')
| -rw-r--r-- | kernel/fs/coda/cnode.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/kernel/fs/coda/cnode.c b/kernel/fs/coda/cnode.c new file mode 100644 index 000000000..7740b1c87 --- /dev/null +++ b/kernel/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); +} + |