[linux-block.git] / fs / coda / cnode.c

// SPDX-License-Identifier: GPL-2.0
/* 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/pagemap.h>
#include "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 = {
	.get_link	= page_get_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_nohighmem(inode);
		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);

	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;
}

struct coda_file_info *coda_ftoc(struct file *file)
{
	struct coda_file_info *cfi = file->private_data;

	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);

	return cfi;

}

/* 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);
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/* cnode related routines for the coda kernel code
	3	(C) 1996 Peter Braam
	4	*/
	5
	6	#include <linux/types.h>
	7	#include <linux/string.h>
	8	#include <linux/time.h>
	9
	10	#include <linux/coda.h>
21fc61c7	11	#include <linux/pagemap.h>
8fc8b9df	12	#include "coda_psdev.h"
31a203df	13	#include "coda_linux.h"
1da177e4 LT	14
	15	static inline int coda_fideq(struct CodaFid fid1, struct CodaFid fid2)
	16	{
	17	return memcmp(fid1, fid2, sizeof(*fid1)) == 0;
	18	}
	19
754661f1	20	static const struct inode_operations coda_symlink_inode_operations = {
6b255391	21	.get_link = page_get_link,
1da177e4 LT	22	.setattr = coda_setattr,
	23	};
	24
	25	/* cnode.c */
	26	static void coda_fill_inode(struct inode inode, struct coda_vattr attr)
	27	{
	28	coda_vattr_to_iattr(inode, attr);
	29
	30	if (S_ISREG(inode->i_mode)) {
	31	inode->i_op = &coda_file_inode_operations;
	32	inode->i_fop = &coda_file_operations;
	33	} else if (S_ISDIR(inode->i_mode)) {
	34	inode->i_op = &coda_dir_inode_operations;
	35	inode->i_fop = &coda_dir_operations;
	36	} else if (S_ISLNK(inode->i_mode)) {
	37	inode->i_op = &coda_symlink_inode_operations;
21fc61c7	38	inode_nohighmem(inode);
1da177e4 LT	39	inode->i_data.a_ops = &coda_symlink_aops;
	40	inode->i_mapping = &inode->i_data;
	41	} else
	42	init_special_inode(inode, inode->i_mode, huge_decode_dev(attr->va_rdev));
	43	}
	44
	45	static int coda_test_inode(struct inode inode, void data)
	46	{
	47	struct CodaFid fid = (struct CodaFid )data;
b5ce1d83 YA	48	struct coda_inode_info *cii = ITOC(inode);
b5ce1d83 YA	49	return coda_fideq(&cii->c_fid, fid);
1da177e4 LT	50	}
	51
	52	static int coda_set_inode(struct inode inode, void data)
	53	{
	54	struct CodaFid fid = (struct CodaFid )data;
b5ce1d83 YA	55	struct coda_inode_info *cii = ITOC(inode);
b5ce1d83 YA	56	cii->c_fid = *fid;
1da177e4 LT	57	return 0;
	58	}
	59
1da177e4 LT	60	struct inode * coda_iget(struct super_block * sb, struct CodaFid * fid,
	61	struct coda_vattr * attr)
	62	{
	63	struct inode *inode;
	64	struct coda_inode_info *cii;
	65	unsigned long hash = coda_f2i(fid);
	66
	67	inode = iget5_locked(sb, hash, coda_test_inode, coda_set_inode, fid);
	68
	69	if (!inode)
	70	return ERR_PTR(-ENOMEM);
	71
	72	if (inode->i_state & I_NEW) {
	73	cii = ITOC(inode);
	74	/* we still need to set i_ino for things like stat(2) */
	75	inode->i_ino = hash;
b5ce1d83	76	/* inode is locked and unique, no need to grab cii->c_lock */
1da177e4 LT	77	cii->c_mapcount = 0;
	78	unlock_new_inode(inode);
	79	}
	80
	81	/* always replace the attributes, type might have changed */
	82	coda_fill_inode(inode, attr);
	83	return inode;
	84	}
	85
	86	/* this is effectively coda_iget:
	87	- get attributes (might be cached)
	88	- get the inode for the fid using vfs iget
	89	- link the two up if this is needed
	90	- fill in the attributes
	91	*/
f4947fbc	92	struct inode coda_cnode_make(struct CodaFid fid, struct super_block *sb)
1da177e4 LT	93	{
1da177e4 LT	94	struct coda_vattr attr;
f4947fbc	95	struct inode *inode;
1da177e4 LT	96	int error;
	97
	98	/* We get inode numbers from Venus -- see venus source */
	99	error = venus_getattr(sb, fid, &attr);
f4947fbc AV	100	if (error)
f4947fbc AV	101	return ERR_PTR(error);
1da177e4	102
f4947fbc AV	103	inode = coda_iget(sb, fid, &attr);
f4947fbc AV	104	if (IS_ERR(inode))
6d6bd94f	105	pr_warn("%s: coda_iget failed\n", __func__);
f4947fbc	106	return inode;
1da177e4 LT	107	}
	108
	109
b5ce1d83 YA	110	/* Although we treat Coda file identifiers as immutable, there is one
	111	* special case for files created during a disconnection where they may
	112	* not be globally unique. When an identifier collision is detected we
	113	* first try to flush the cached inode from the kernel and finally
	114	* resort to renaming/rehashing in-place. Userspace remembers both old
	115	* and new values of the identifier to handle any in-flight upcalls.
	116	* The real solution is to use globally unique UUIDs as identifiers, but
	117	* retrofitting the existing userspace code for this is non-trivial. */
1da177e4 LT	118	void coda_replace_fid(struct inode inode, struct CodaFid oldfid,
	119	struct CodaFid *newfid)
	120	{
b5ce1d83	121	struct coda_inode_info *cii = ITOC(inode);
1da177e4 LT	122	unsigned long hash = coda_f2i(newfid);
1da177e4 LT	123
c5d3237c	124	BUG_ON(!coda_fideq(&cii->c_fid, oldfid));
1da177e4 LT	125
	126	/* replace fid and rehash inode */
	127	/* XXX we probably need to hold some lock here! */
	128	remove_inode_hash(inode);
	129	cii->c_fid = *newfid;
	130	inode->i_ino = hash;
	131	__insert_inode_hash(inode, hash);
	132	}
	133
	134	/* convert a fid to an inode. */
	135	struct inode coda_fid_to_inode(struct CodaFid fid, struct super_block *sb)
	136	{
	137	struct inode *inode;
	138	unsigned long hash = coda_f2i(fid);
	139
ed31a7dd	140	inode = ilookup5(sb, hash, coda_test_inode, fid);
1da177e4 LT	141	if ( !inode )
	142	return NULL;
	143
	144	/* we should never see newly created inodes because we intentionally
	145	* fail in the initialization callback */
	146	BUG_ON(inode->i_state & I_NEW);
	147
	148	return inode;
	149	}
	150
5bb44810 FF	151	struct coda_file_info coda_ftoc(struct file file)
	152	{
	153	struct coda_file_info *cfi = file->private_data;
	154
	155	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	156
	157	return cfi;
	158
	159	}
	160
1da177e4	161	/* the CONTROL inode is made without asking attributes from Venus */
0b2c4e39	162	struct inode coda_cnode_makectl(struct super_block sb)
1da177e4	163	{
0b2c4e39 AV	164	struct inode *inode = new_inode(sb);
	165	if (inode) {
	166	inode->i_ino = CTL_INO;
	167	inode->i_op = &coda_ioctl_inode_operations;
	168	inode->i_fop = &coda_ioctl_operations;
	169	inode->i_mode = 0444;
	170	return inode;
1da177e4	171	}
0b2c4e39	172	return ERR_PTR(-ENOMEM);
1da177e4 LT	173	}
1da177e4 LT	174