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linux/fs/jffs2/nodelist.h
David Woodhouse be629c62a6 Fix directory hardlinks from deleted directories 
When a directory is deleted, we don't take too much care about killing off
all the dirents that belong to it — on the basis that on remount, the scan
will conclude that the directory is dead anyway.

This doesn't work though, when the deleted directory contained a child
directory which was moved *out*. In the early stages of the fs build
we can then end up with an apparent hard link, with the child directory
appearing both in its true location, and as a child of the original
directory which are this stage of the mount process we don't *yet* know
is defunct.

To resolve this, take out the early special-casing of the "directories
shall not have hard links" rule in jffs2_build_inode_pass1(), and let the
normal nlink processing happen for directories as well as other inodes.

Then later in the build process we can set ic->pino_nlink to the parent
inode#, as is required for directories during normal operaton, instead
of the nlink. And complain only *then* about hard links which are still
in evidence even after killing off all the unreachable paths.

Reported-by: Liu Song <liu.song11@zte.com.cn>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@vger.kernel.org
2016-02-25 11:11:28 +00:00

485 lines
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/*
* JFFS2 -- Journalling Flash File System, Version 2.
*
* Copyright © 2001-2007 Red Hat, Inc.
*
* Created by David Woodhouse <dwmw2@infradead.org>
*
* For licensing information, see the file 'LICENCE' in this directory.
*
*/
#ifndef __JFFS2_NODELIST_H__
#define __JFFS2_NODELIST_H__
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/jffs2.h>
#include "jffs2_fs_sb.h"
#include "jffs2_fs_i.h"
#include "xattr.h"
#include "acl.h"
#include "summary.h"
#ifdef __ECOS
#include "os-ecos.h"
#else
#include "os-linux.h"
#endif
#define JFFS2_NATIVE_ENDIAN
/* Note we handle mode bits conversion from JFFS2 (i.e. Linux) to/from
whatever OS we're actually running on here too. */
#if defined(JFFS2_NATIVE_ENDIAN)
#define cpu_to_je16(x) ((jint16_t){x})
#define cpu_to_je32(x) ((jint32_t){x})
#define cpu_to_jemode(x) ((jmode_t){os_to_jffs2_mode(x)})
#define constant_cpu_to_je16(x) ((jint16_t){x})
#define constant_cpu_to_je32(x) ((jint32_t){x})
#define je16_to_cpu(x) ((x).v16)
#define je32_to_cpu(x) ((x).v32)
#define jemode_to_cpu(x) (jffs2_to_os_mode((x).m))
#elif defined(JFFS2_BIG_ENDIAN)
#define cpu_to_je16(x) ((jint16_t){cpu_to_be16(x)})
#define cpu_to_je32(x) ((jint32_t){cpu_to_be32(x)})
#define cpu_to_jemode(x) ((jmode_t){cpu_to_be32(os_to_jffs2_mode(x))})
#define constant_cpu_to_je16(x) ((jint16_t){__constant_cpu_to_be16(x)})
#define constant_cpu_to_je32(x) ((jint32_t){__constant_cpu_to_be32(x)})
#define je16_to_cpu(x) (be16_to_cpu(x.v16))
#define je32_to_cpu(x) (be32_to_cpu(x.v32))
#define jemode_to_cpu(x) (be32_to_cpu(jffs2_to_os_mode((x).m)))
#elif defined(JFFS2_LITTLE_ENDIAN)
#define cpu_to_je16(x) ((jint16_t){cpu_to_le16(x)})
#define cpu_to_je32(x) ((jint32_t){cpu_to_le32(x)})
#define cpu_to_jemode(x) ((jmode_t){cpu_to_le32(os_to_jffs2_mode(x))})
#define constant_cpu_to_je16(x) ((jint16_t){__constant_cpu_to_le16(x)})
#define constant_cpu_to_je32(x) ((jint32_t){__constant_cpu_to_le32(x)})
#define je16_to_cpu(x) (le16_to_cpu(x.v16))
#define je32_to_cpu(x) (le32_to_cpu(x.v32))
#define jemode_to_cpu(x) (le32_to_cpu(jffs2_to_os_mode((x).m)))
#else
#error wibble
#endif
/* The minimal node header size */
#define JFFS2_MIN_NODE_HEADER sizeof(struct jffs2_raw_dirent)
/*
This is all we need to keep in-core for each raw node during normal
operation. As and when we do read_inode on a particular inode, we can
scan the nodes which are listed for it and build up a proper map of
which nodes are currently valid. JFFSv1 always used to keep that whole
map in core for each inode.
*/
struct jffs2_raw_node_ref
{
struct jffs2_raw_node_ref *next_in_ino; /* Points to the next raw_node_ref
for this object. If this _is_ the last, it points to the inode_cache,
xattr_ref or xattr_datum instead. The common part of those structures
has NULL in the first word. See jffs2_raw_ref_to_ic() below */
uint32_t flash_offset;
#undef TEST_TOTLEN
#ifdef TEST_TOTLEN
uint32_t __totlen; /* This may die; use ref_totlen(c, jeb, ) below */
#endif
};
#define REF_LINK_NODE ((int32_t)-1)
#define REF_EMPTY_NODE ((int32_t)-2)
/* Use blocks of about 256 bytes */
#define REFS_PER_BLOCK ((255/sizeof(struct jffs2_raw_node_ref))-1)
static inline struct jffs2_raw_node_ref *ref_next(struct jffs2_raw_node_ref *ref)
{
ref++;
/* Link to another block of refs */
if (ref->flash_offset == REF_LINK_NODE) {
ref = ref->next_in_ino;
if (!ref)
return ref;
}
/* End of chain */
if (ref->flash_offset == REF_EMPTY_NODE)
return NULL;
return ref;
}
static inline struct jffs2_inode_cache *jffs2_raw_ref_to_ic(struct jffs2_raw_node_ref *raw)
{
while(raw->next_in_ino)
raw = raw->next_in_ino;
/* NB. This can be a jffs2_xattr_datum or jffs2_xattr_ref and
not actually a jffs2_inode_cache. Check ->class */
return ((struct jffs2_inode_cache *)raw);
}
/* flash_offset & 3 always has to be zero, because nodes are
always aligned at 4 bytes. So we have a couple of extra bits
to play with, which indicate the node's status; see below: */
#define REF_UNCHECKED 0 /* We haven't yet checked the CRC or built its inode */
#define REF_OBSOLETE 1 /* Obsolete, can be completely ignored */
#define REF_PRISTINE 2 /* Completely clean. GC without looking */
#define REF_NORMAL 3 /* Possibly overlapped. Read the page and write again on GC */
#define ref_flags(ref) ((ref)->flash_offset & 3)
#define ref_offset(ref) ((ref)->flash_offset & ~3)
#define ref_obsolete(ref) (((ref)->flash_offset & 3) == REF_OBSOLETE)
#define mark_ref_normal(ref) do { (ref)->flash_offset = ref_offset(ref) | REF_NORMAL; } while(0)
/* Dirent nodes should be REF_PRISTINE only if they are not a deletion
dirent. Deletion dirents should be REF_NORMAL so that GC gets to
throw them away when appropriate */
#define dirent_node_state(rd) ( (je32_to_cpu((rd)->ino)?REF_PRISTINE:REF_NORMAL) )
/* NB: REF_PRISTINE for an inode-less node (ref->next_in_ino == NULL) indicates
it is an unknown node of type JFFS2_NODETYPE_RWCOMPAT_COPY, so it'll get
copied. If you need to do anything different to GC inode-less nodes, then
you need to modify gc.c accordingly. */
/* For each inode in the filesystem, we need to keep a record of
nlink, because it would be a PITA to scan the whole directory tree
at read_inode() time to calculate it, and to keep sufficient information
in the raw_node_ref (basically both parent and child inode number for
dirent nodes) would take more space than this does. We also keep
a pointer to the first physical node which is part of this inode, too.
*/
struct jffs2_inode_cache {
/* First part of structure is shared with other objects which
can terminate the raw node refs' next_in_ino list -- which
currently struct jffs2_xattr_datum and struct jffs2_xattr_ref. */
struct jffs2_full_dirent *scan_dents; /* Used during scan to hold
temporary lists of dirents, and later must be set to
NULL to mark the end of the raw_node_ref->next_in_ino
chain. */
struct jffs2_raw_node_ref *nodes;
uint8_t class; /* It's used for identification */
/* end of shared structure */
uint8_t flags;
uint16_t state;
uint32_t ino;
struct jffs2_inode_cache *next;
#ifdef CONFIG_JFFS2_FS_XATTR
struct jffs2_xattr_ref *xref;
#endif
uint32_t pino_nlink; /* Directories store parent inode
here; other inodes store nlink.
Zero always means that it's
completely unlinked. */
};
/* Inode states for 'state' above. We need the 'GC' state to prevent
someone from doing a read_inode() while we're moving a 'REF_PRISTINE'
node without going through all the iget() nonsense */
#define INO_STATE_UNCHECKED 0 /* CRC checks not yet done */
#define INO_STATE_CHECKING 1 /* CRC checks in progress */
#define INO_STATE_PRESENT 2 /* In core */
#define INO_STATE_CHECKEDABSENT 3 /* Checked, cleared again */
#define INO_STATE_GC 4 /* GCing a 'pristine' node */
#define INO_STATE_READING 5 /* In read_inode() */
#define INO_STATE_CLEARING 6 /* In clear_inode() */
#define INO_FLAGS_XATTR_CHECKED 0x01 /* has no duplicate xattr_ref */
#define INO_FLAGS_IS_DIR 0x02 /* is a directory */
#define RAWNODE_CLASS_INODE_CACHE 0
#define RAWNODE_CLASS_XATTR_DATUM 1
#define RAWNODE_CLASS_XATTR_REF 2
#define INOCACHE_HASHSIZE_MIN 128
#define INOCACHE_HASHSIZE_MAX 1024
#define write_ofs(c) ((c)->nextblock->offset + (c)->sector_size - (c)->nextblock->free_size)
/*
Larger representation of a raw node, kept in-core only when the
struct inode for this particular ino is instantiated.
*/
struct jffs2_full_dnode
{
struct jffs2_raw_node_ref *raw;
uint32_t ofs; /* The offset to which the data of this node belongs */
uint32_t size;
uint32_t frags; /* Number of fragments which currently refer
to this node. When this reaches zero,
the node is obsolete. */
};
/*
Even larger representation of a raw node, kept in-core only while
we're actually building up the original map of which nodes go where,
in read_inode()
*/
struct jffs2_tmp_dnode_info
{
struct rb_node rb;
struct jffs2_full_dnode *fn;
uint32_t version;
uint32_t data_crc;
uint32_t partial_crc;
uint32_t csize;
uint16_t overlapped;
};
/* Temporary data structure used during readinode. */
struct jffs2_readinode_info
{
struct rb_root tn_root;
struct jffs2_tmp_dnode_info *mdata_tn;
uint32_t highest_version;
uint32_t latest_mctime;
uint32_t mctime_ver;
struct jffs2_full_dirent *fds;
struct jffs2_raw_node_ref *latest_ref;
};
struct jffs2_full_dirent
{
union {
struct jffs2_raw_node_ref *raw;
struct jffs2_inode_cache *ic; /* Just during part of build */
};
struct jffs2_full_dirent *next;
uint32_t version;
uint32_t ino; /* == zero for unlink */
unsigned int nhash;
unsigned char type;
unsigned char name[0];
};
/*
Fragments - used to build a map of which raw node to obtain
data from for each part of the ino
*/
struct jffs2_node_frag
{
struct rb_node rb;
struct jffs2_full_dnode *node; /* NULL for holes */
uint32_t size;
uint32_t ofs; /* The offset to which this fragment belongs */
};
struct jffs2_eraseblock
{
struct list_head list;
int bad_count;
uint32_t offset; /* of this block in the MTD */
uint32_t unchecked_size;
uint32_t used_size;
uint32_t dirty_size;
uint32_t wasted_size;
uint32_t free_size; /* Note that sector_size - free_size
is the address of the first free space */
uint32_t allocated_refs;
struct jffs2_raw_node_ref *first_node;
struct jffs2_raw_node_ref *last_node;
struct jffs2_raw_node_ref *gc_node; /* Next node to be garbage collected */
};
static inline int jffs2_blocks_use_vmalloc(struct jffs2_sb_info *c)
{
return ((c->flash_size / c->sector_size) * sizeof (struct jffs2_eraseblock)) > (128 * 1024);
}
#define ref_totlen(a, b, c) __jffs2_ref_totlen((a), (b), (c))
#define ALLOC_NORMAL 0 /* Normal allocation */
#define ALLOC_DELETION 1 /* Deletion node. Best to allow it */
#define ALLOC_GC 2 /* Space requested for GC. Give it or die */
#define ALLOC_NORETRY 3 /* For jffs2_write_dnode: On failure, return -EAGAIN instead of retrying */
/* How much dirty space before it goes on the very_dirty_list */
#define VERYDIRTY(c, size) ((size) >= ((c)->sector_size / 2))
/* check if dirty space is more than 255 Byte */
#define ISDIRTY(size) ((size) > sizeof (struct jffs2_raw_inode) + JFFS2_MIN_DATA_LEN)
#define PAD(x) (((x)+3)&~3)
static inline int jffs2_encode_dev(union jffs2_device_node *jdev, dev_t rdev)
{
if (old_valid_dev(rdev)) {
jdev->old_id = cpu_to_je16(old_encode_dev(rdev));
return sizeof(jdev->old_id);
} else {
jdev->new_id = cpu_to_je32(new_encode_dev(rdev));
return sizeof(jdev->new_id);
}
}
static inline struct jffs2_node_frag *frag_first(struct rb_root *root)
{
struct rb_node *node = rb_first(root);
if (!node)
return NULL;
return rb_entry(node, struct jffs2_node_frag, rb);
}
static inline struct jffs2_node_frag *frag_last(struct rb_root *root)
{
struct rb_node *node = rb_last(root);
if (!node)
return NULL;
return rb_entry(node, struct jffs2_node_frag, rb);
}
#define frag_next(frag) rb_entry(rb_next(&(frag)->rb), struct jffs2_node_frag, rb)
#define frag_prev(frag) rb_entry(rb_prev(&(frag)->rb), struct jffs2_node_frag, rb)
#define frag_parent(frag) rb_entry(rb_parent(&(frag)->rb), struct jffs2_node_frag, rb)
#define frag_left(frag) rb_entry((frag)->rb.rb_left, struct jffs2_node_frag, rb)
#define frag_right(frag) rb_entry((frag)->rb.rb_right, struct jffs2_node_frag, rb)
#define frag_erase(frag, list) rb_erase(&frag->rb, list);
#define tn_next(tn) rb_entry(rb_next(&(tn)->rb), struct jffs2_tmp_dnode_info, rb)
#define tn_prev(tn) rb_entry(rb_prev(&(tn)->rb), struct jffs2_tmp_dnode_info, rb)
#define tn_parent(tn) rb_entry(rb_parent(&(tn)->rb), struct jffs2_tmp_dnode_info, rb)
#define tn_left(tn) rb_entry((tn)->rb.rb_left, struct jffs2_tmp_dnode_info, rb)
#define tn_right(tn) rb_entry((tn)->rb.rb_right, struct jffs2_tmp_dnode_info, rb)
#define tn_erase(tn, list) rb_erase(&tn->rb, list);
#define tn_last(list) rb_entry(rb_last(list), struct jffs2_tmp_dnode_info, rb)
#define tn_first(list) rb_entry(rb_first(list), struct jffs2_tmp_dnode_info, rb)
/* nodelist.c */
void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list);
void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state);
struct jffs2_inode_cache *jffs2_get_ino_cache(struct jffs2_sb_info *c, uint32_t ino);
void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new);
void jffs2_del_ino_cache(struct jffs2_sb_info *c, struct jffs2_inode_cache *old);
void jffs2_free_ino_caches(struct jffs2_sb_info *c);
void jffs2_free_raw_node_refs(struct jffs2_sb_info *c);
struct jffs2_node_frag *jffs2_lookup_node_frag(struct rb_root *fragtree, uint32_t offset);
void jffs2_kill_fragtree(struct rb_root *root, struct jffs2_sb_info *c_delete);
int jffs2_add_full_dnode_to_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, struct jffs2_full_dnode *fn);
uint32_t jffs2_truncate_fragtree (struct jffs2_sb_info *c, struct rb_root *list, uint32_t size);
struct jffs2_raw_node_ref *jffs2_link_node_ref(struct jffs2_sb_info *c,
struct jffs2_eraseblock *jeb,
uint32_t ofs, uint32_t len,
struct jffs2_inode_cache *ic);
extern uint32_t __jffs2_ref_totlen(struct jffs2_sb_info *c,
struct jffs2_eraseblock *jeb,
struct jffs2_raw_node_ref *ref);
/* nodemgmt.c */
int jffs2_thread_should_wake(struct jffs2_sb_info *c);
int jffs2_reserve_space(struct jffs2_sb_info *c, uint32_t minsize,
uint32_t *len, int prio, uint32_t sumsize);
int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize,
uint32_t *len, uint32_t sumsize);
struct jffs2_raw_node_ref *jffs2_add_physical_node_ref(struct jffs2_sb_info *c,
uint32_t ofs, uint32_t len,
struct jffs2_inode_cache *ic);
void jffs2_complete_reservation(struct jffs2_sb_info *c);
void jffs2_mark_node_obsolete(struct jffs2_sb_info *c, struct jffs2_raw_node_ref *raw);
/* write.c */
int jffs2_do_new_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, uint32_t mode, struct jffs2_raw_inode *ri);
struct jffs2_full_dnode *jffs2_write_dnode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
struct jffs2_raw_inode *ri, const unsigned char *data,
uint32_t datalen, int alloc_mode);
struct jffs2_full_dirent *jffs2_write_dirent(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
struct jffs2_raw_dirent *rd, const unsigned char *name,
uint32_t namelen, int alloc_mode);
int jffs2_write_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
struct jffs2_raw_inode *ri, unsigned char *buf,
uint32_t offset, uint32_t writelen, uint32_t *retlen);
int jffs2_do_create(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, struct jffs2_inode_info *f,
struct jffs2_raw_inode *ri, const struct qstr *qstr);
int jffs2_do_unlink(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, const char *name,
int namelen, struct jffs2_inode_info *dead_f, uint32_t time);
int jffs2_do_link(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, uint32_t ino,
uint8_t type, const char *name, int namelen, uint32_t time);
/* readinode.c */
int jffs2_do_read_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
uint32_t ino, struct jffs2_raw_inode *latest_node);
int jffs2_do_crccheck_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic);
void jffs2_do_clear_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f);
/* malloc.c */
int jffs2_create_slab_caches(void);
void jffs2_destroy_slab_caches(void);
struct jffs2_full_dirent *jffs2_alloc_full_dirent(int namesize);
void jffs2_free_full_dirent(struct jffs2_full_dirent *);
struct jffs2_full_dnode *jffs2_alloc_full_dnode(void);
void jffs2_free_full_dnode(struct jffs2_full_dnode *);
struct jffs2_raw_dirent *jffs2_alloc_raw_dirent(void);
void jffs2_free_raw_dirent(struct jffs2_raw_dirent *);
struct jffs2_raw_inode *jffs2_alloc_raw_inode(void);
void jffs2_free_raw_inode(struct jffs2_raw_inode *);
struct jffs2_tmp_dnode_info *jffs2_alloc_tmp_dnode_info(void);
void jffs2_free_tmp_dnode_info(struct jffs2_tmp_dnode_info *);
int jffs2_prealloc_raw_node_refs(struct jffs2_sb_info *c,
struct jffs2_eraseblock *jeb, int nr);
void jffs2_free_refblock(struct jffs2_raw_node_ref *);
struct jffs2_node_frag *jffs2_alloc_node_frag(void);
void jffs2_free_node_frag(struct jffs2_node_frag *);
struct jffs2_inode_cache *jffs2_alloc_inode_cache(void);
void jffs2_free_inode_cache(struct jffs2_inode_cache *);
#ifdef CONFIG_JFFS2_FS_XATTR
struct jffs2_xattr_datum *jffs2_alloc_xattr_datum(void);
void jffs2_free_xattr_datum(struct jffs2_xattr_datum *);
struct jffs2_xattr_ref *jffs2_alloc_xattr_ref(void);
void jffs2_free_xattr_ref(struct jffs2_xattr_ref *);
#endif
/* gc.c */
int jffs2_garbage_collect_pass(struct jffs2_sb_info *c);
/* read.c */
int jffs2_read_dnode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
struct jffs2_full_dnode *fd, unsigned char *buf,
int ofs, int len);
int jffs2_read_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
unsigned char *buf, uint32_t offset, uint32_t len);
char *jffs2_getlink(struct jffs2_sb_info *c, struct jffs2_inode_info *f);
/* scan.c */
int jffs2_scan_medium(struct jffs2_sb_info *c);
void jffs2_rotate_lists(struct jffs2_sb_info *c);
struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino);
int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
int jffs2_scan_dirty_space(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, uint32_t size);
/* build.c */
int jffs2_do_mount_fs(struct jffs2_sb_info *c);
/* erase.c */
int jffs2_erase_pending_blocks(struct jffs2_sb_info *c, int count);
void jffs2_free_jeb_node_refs(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
/* wbuf.c */
int jffs2_flush_wbuf_gc(struct jffs2_sb_info *c, uint32_t ino);
int jffs2_flush_wbuf_pad(struct jffs2_sb_info *c);
int jffs2_check_nand_cleanmarker(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
int jffs2_write_nand_cleanmarker(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
#endif
#include "debug.h"
#endif /* __JFFS2_NODELIST_H__ */
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