cregit-Linux how code gets into the kernel

Release 4.11 fs/jffs2/dir.c

Directory: fs/jffs2
/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2007 Red Hat, Inc.
 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
 *
 * Created by David Woodhouse <dwmw2@infradead.org>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/crc32.h>
#include <linux/jffs2.h>
#include "jffs2_fs_i.h"
#include "jffs2_fs_sb.h"
#include <linux/time.h>
#include "nodelist.h"

static int jffs2_readdir (struct file *, struct dir_context *);

static int jffs2_create (struct inode *,struct dentry *,umode_t,
			 bool);
static struct dentry *jffs2_lookup (struct inode *,struct dentry *,
				    unsigned int);
static int jffs2_link (struct dentry *,struct inode *,struct dentry *);
static int jffs2_unlink (struct inode *,struct dentry *);
static int jffs2_symlink (struct inode *,struct dentry *,const char *);
static int jffs2_mkdir (struct inode *,struct dentry *,umode_t);
static int jffs2_rmdir (struct inode *,struct dentry *);
static int jffs2_mknod (struct inode *,struct dentry *,umode_t,dev_t);
static int jffs2_rename (struct inode *, struct dentry *,
			 struct inode *, struct dentry *,
			 unsigned int);


const struct file_operations jffs2_dir_operations =
{
	.read =		generic_read_dir,
	.iterate_shared=jffs2_readdir,
	.unlocked_ioctl=jffs2_ioctl,
	.fsync =	jffs2_fsync,
	.llseek =	generic_file_llseek,
};



const struct inode_operations jffs2_dir_inode_operations =
{
	.create =	jffs2_create,
	.lookup =	jffs2_lookup,
	.link =		jffs2_link,
	.unlink =	jffs2_unlink,
	.symlink =	jffs2_symlink,
	.mkdir =	jffs2_mkdir,
	.rmdir =	jffs2_rmdir,
	.mknod =	jffs2_mknod,
	.rename =	jffs2_rename,
	.get_acl =	jffs2_get_acl,
	.set_acl =	jffs2_set_acl,
	.setattr =	jffs2_setattr,
	.listxattr =	jffs2_listxattr,
};

/***********************************************************************/


/* We keep the dirent list sorted in increasing order of name hash,
   and we use the same hash function as the dentries. Makes this
   nice and simple
*/

static struct dentry *jffs2_lookup(struct inode *dir_i, struct dentry *target, unsigned int flags) { struct jffs2_inode_info *dir_f; struct jffs2_full_dirent *fd = NULL, *fd_list; uint32_t ino = 0; struct inode *inode = NULL; unsigned int nhash; jffs2_dbg(1, "jffs2_lookup()\n"); if (target->d_name.len > JFFS2_MAX_NAME_LEN) return ERR_PTR(-ENAMETOOLONG); dir_f = JFFS2_INODE_INFO(dir_i); /* The 'nhash' on the fd_list is not the same as the dentry hash */ nhash = full_name_hash(NULL, target->d_name.name, target->d_name.len); mutex_lock(&dir_f->sem); /* NB: The 2.2 backport will need to explicitly check for '.' and '..' here */ for (fd_list = dir_f->dents; fd_list && fd_list->nhash <= nhash; fd_list = fd_list->next) { if (fd_list->nhash == nhash && (!fd || fd_list->version > fd->version) && strlen(fd_list->name) == target->d_name.len && !strncmp(fd_list->name, target->d_name.name, target->d_name.len)) { fd = fd_list; } } if (fd) ino = fd->ino; mutex_unlock(&dir_f->sem); if (ino) { inode = jffs2_iget(dir_i->i_sb, ino); if (IS_ERR(inode)) pr_warn("iget() failed for ino #%u\n", ino); } return d_splice_alias(inode, target); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds21885.83%218.18%
Richard Purdie176.69%19.09%
David Woodhouse72.76%327.27%
Joe Perches41.57%218.18%
David Howells41.57%19.09%
Al Viro31.18%19.09%
Trond Myklebust10.39%19.09%
Total254100.00%11100.00%

/***********************************************************************/
static int jffs2_readdir(struct file *file, struct dir_context *ctx) { struct inode *inode = file_inode(file); struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); struct jffs2_full_dirent *fd; unsigned long curofs = 1; jffs2_dbg(1, "jffs2_readdir() for dir_i #%lu\n", inode->i_ino); if (!dir_emit_dots(file, ctx)) return 0; mutex_lock(&f->sem); for (fd = f->dents; fd; fd = fd->next) { curofs++; /* First loop: curofs = 2; pos = 2 */ if (curofs < ctx->pos) { jffs2_dbg(2, "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n", fd->name, fd->ino, fd->type, curofs, (unsigned long)ctx->pos); continue; } if (!fd->ino) { jffs2_dbg(2, "Skipping deletion dirent \"%s\"\n", fd->name); ctx->pos++; continue; } jffs2_dbg(2, "Dirent %ld: \"%s\", ino #%u, type %d\n", (unsigned long)ctx->pos, fd->name, fd->ino, fd->type); if (!dir_emit(ctx, fd->name, strlen(fd->name), fd->ino, fd->type)) break; ctx->pos++; } mutex_unlock(&f->sem); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds17071.43%116.67%
Al Viro5322.27%233.33%
Joe Perches125.04%116.67%
David Woodhouse20.84%116.67%
Dave Jones10.42%116.67%
Total238100.00%6100.00%

/***********************************************************************/
static int jffs2_create(struct inode *dir_i, struct dentry *dentry, umode_t mode, bool excl) { struct jffs2_raw_inode *ri; struct jffs2_inode_info *f, *dir_f; struct jffs2_sb_info *c; struct inode *inode; int ret; ri = jffs2_alloc_raw_inode(); if (!ri) return -ENOMEM; c = JFFS2_SB_INFO(dir_i->i_sb); jffs2_dbg(1, "%s()\n", __func__); inode = jffs2_new_inode(dir_i, mode, ri); if (IS_ERR(inode)) { jffs2_dbg(1, "jffs2_new_inode() failed\n"); jffs2_free_raw_inode(ri); return PTR_ERR(inode); } inode->i_op = &jffs2_file_inode_operations; inode->i_fop = &jffs2_file_operations; inode->i_mapping->a_ops = &jffs2_file_address_operations; inode->i_mapping->nrpages = 0; f = JFFS2_INODE_INFO(inode); dir_f = JFFS2_INODE_INFO(dir_i); /* jffs2_do_create() will want to lock it, _after_ reserving space and taking c-alloc_sem. If we keep it locked here, lockdep gets unhappy (although it's a false positive; nothing else will be looking at this inode yet so there's no chance of AB-BA deadlock involving its f->sem). */ mutex_unlock(&f->sem); ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name); if (ret) goto fail; dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime)); jffs2_free_raw_inode(ri); jffs2_dbg(1, "%s(): Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n", __func__, inode->i_ino, inode->i_mode, inode->i_nlink, f->inocache->pino_nlink, inode->i_mapping->nrpages); unlock_new_inode(inode); d_instantiate(dentry, inode); return 0; fail: iget_failed(inode); jffs2_free_raw_inode(ri); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds16357.60%15.88%
David Woodhouse7626.86%635.29%
KaiGai Kohei176.01%15.88%
Joe Perches155.30%15.88%
Al Viro93.18%529.41%
Eric Paris10.35%15.88%
Andi Kleen10.35%15.88%
Trond Myklebust10.35%15.88%
Total283100.00%17100.00%

/***********************************************************************/
static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry) { struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb); struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i); struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(d_inode(dentry)); int ret; uint32_t now = get_seconds(); ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name, dentry->d_name.len, dead_f, now); if (dead_f->inocache) set_nlink(d_inode(dentry), dead_f->inocache->pino_nlink); if (!ret) dir_i->i_mtime = dir_i->i_ctime = ITIME(now); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
David Woodhouse5241.27%342.86%
Linus Torvalds3830.16%114.29%
Artem B. Bityutskiy2620.63%114.29%
David Howells64.76%114.29%
Miklos Szeredi43.17%114.29%
Total126100.00%7100.00%

/***********************************************************************/
static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry) { struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_sb); struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry)); struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i); int ret; uint8_t type; uint32_t now; /* Don't let people make hard links to bad inodes. */ if (!f->inocache) return -EIO; if (d_is_dir(old_dentry)) return -EPERM; /* XXX: This is ugly */ type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12; if (!type) type = DT_REG; now = get_seconds(); ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now); if (!ret) { mutex_lock(&f->sem); set_nlink(d_inode(old_dentry), ++f->inocache->pino_nlink); mutex_unlock(&f->sem); d_instantiate(dentry, d_inode(old_dentry)); dir_i->i_mtime = dir_i->i_ctime = ITIME(now); ihold(d_inode(old_dentry)); } return ret; }

Contributors

PersonTokensPropCommitsCommitProp
David Woodhouse10949.32%430.77%
Linus Torvalds5123.08%17.69%
Artem B. Bityutskiy2310.41%17.69%
David Howells177.69%215.38%
Dave Jones104.52%17.69%
Al Viro73.17%323.08%
Miklos Szeredi41.81%17.69%
Total221100.00%13100.00%

/***********************************************************************/
static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target) { struct jffs2_inode_info *f, *dir_f; struct jffs2_sb_info *c; struct inode *inode; struct jffs2_raw_inode *ri; struct jffs2_raw_dirent *rd; struct jffs2_full_dnode *fn; struct jffs2_full_dirent *fd; int namelen; uint32_t alloclen; int ret, targetlen = strlen(target); /* FIXME: If you care. We'd need to use frags for the target if it grows much more than this */ if (targetlen > 254) return -ENAMETOOLONG; ri = jffs2_alloc_raw_inode(); if (!ri) return -ENOMEM; c = JFFS2_SB_INFO(dir_i->i_sb); /* Try to reserve enough space for both node and dirent. * Just the node will do for now, though */ namelen = dentry->d_name.len; ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen, ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); if (ret) { jffs2_free_raw_inode(ri); return ret; } inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri); if (IS_ERR(inode)) { jffs2_free_raw_inode(ri); jffs2_complete_reservation(c); return PTR_ERR(inode); } inode->i_op = &jffs2_symlink_inode_operations; f = JFFS2_INODE_INFO(inode); inode->i_size = targetlen; ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size); ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size); ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4)); ri->compr = JFFS2_COMPR_NONE; ri->data_crc = cpu_to_je32(crc32(0, target, targetlen)); ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8)); fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL); jffs2_free_raw_inode(ri); if (IS_ERR(fn)) { /* Eeek. Wave bye bye */ mutex_unlock(&f->sem); jffs2_complete_reservation(c); ret = PTR_ERR(fn); goto fail; } /* We use f->target field to store the target path. */ f->target = kmemdup(target, targetlen + 1, GFP_KERNEL); if (!f->target) { pr_warn("Can't allocate %d bytes of memory\n", targetlen + 1); mutex_unlock(&f->sem); jffs2_complete_reservation(c); ret = -ENOMEM; goto fail; } inode->i_link = f->target; jffs2_dbg(1, "%s(): symlink's target '%s' cached\n", __func__, (char *)f->target); /* No data here. Only a metadata node, which will be obsoleted by the first data write */ f->metadata = fn; mutex_unlock(&f->sem); jffs2_complete_reservation(c); ret = jffs2_init_security(inode, dir_i, &dentry->d_name); if (ret) goto fail; ret = jffs2_init_acl_post(inode); if (ret) goto fail; ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen, ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen)); if (ret) goto fail; rd = jffs2_alloc_raw_dirent(); if (!rd) { /* Argh. Now we treat it like a normal delete */ jffs2_complete_reservation(c); ret = -ENOMEM; goto fail; } dir_f = JFFS2_INODE_INFO(dir_i); mutex_lock(&dir_f->sem); rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT); rd->totlen = cpu_to_je32(sizeof(*rd) + namelen); rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4)); rd->pino = cpu_to_je32(dir_i->i_ino); rd->version = cpu_to_je32(++dir_f->highest_version); rd->ino = cpu_to_je32(inode->i_ino); rd->mctime = cpu_to_je32(get_seconds()); rd->nsize = namelen; rd->type = DT_LNK; rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8)); rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen)); fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL); if (IS_ERR(fd)) { /* dirent failed to write. Delete the inode normally as if it were the final unlink() */ jffs2_complete_reservation(c); jffs2_free_raw_dirent(rd); mutex_unlock(&dir_f->sem); ret = PTR_ERR(fd); goto fail; } dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime)); jffs2_free_raw_dirent(rd); /* Link the fd into the inode's list, obsoleting an old one if necessary. */ jffs2_add_fd_to_list(c, fd, &dir_f->dents); mutex_unlock(&dir_f->sem); jffs2_complete_reservation(c); unlock_new_inode(inode); d_instantiate(dentry, inode); return 0; fail: iget_failed(inode); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds57266.28%14.17%
David Woodhouse12814.83%729.17%
Artem B. Bityutskiy677.76%28.33%
Dave Jones303.48%14.17%
KaiGai Kohei242.78%28.33%
Al Viro131.51%312.50%
Joe Perches70.81%28.33%
Ferenc Havasi70.81%14.17%
Eric Paris50.58%14.17%
Julia Lawall30.35%14.17%
Thomas Gleixner30.35%14.17%
Andi Kleen30.35%14.17%
Adrian Hunter10.12%14.17%
Total863100.00%24100.00%


static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode) { struct jffs2_inode_info *f, *dir_f; struct jffs2_sb_info *c; struct inode *inode; struct jffs2_raw_inode *ri; struct jffs2_raw_dirent *rd; struct jffs2_full_dnode *fn; struct jffs2_full_dirent *fd; int namelen; uint32_t alloclen; int ret; mode |= S_IFDIR; ri = jffs2_alloc_raw_inode(); if (!ri) return -ENOMEM; c = JFFS2_SB_INFO(dir_i->i_sb); /* Try to reserve enough space for both node and dirent. * Just the node will do for now, though */ namelen = dentry->d_name.len; ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); if (ret) { jffs2_free_raw_inode(ri); return ret; } inode = jffs2_new_inode(dir_i, mode, ri); if (IS_ERR(inode)) { jffs2_free_raw_inode(ri); jffs2_complete_reservation(c); return PTR_ERR(inode); } inode->i_op = &jffs2_dir_inode_operations; inode->i_fop = &jffs2_dir_operations; f = JFFS2_INODE_INFO(inode); /* Directories get nlink 2 at start */ set_nlink(inode, 2); /* but ic->pino_nlink is the parent ino# */ f->inocache->pino_nlink = dir_i->i_ino; ri->data_crc = cpu_to_je32(0); ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8)); fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL); jffs2_free_raw_inode(ri); if (IS_ERR(fn)) { /* Eeek. Wave bye bye */ mutex_unlock(&f->sem); jffs2_complete_reservation(c); ret = PTR_ERR(fn); goto fail; } /* No data here. Only a metadata node, which will be obsoleted by the first data write */ f->metadata = fn; mutex_unlock(&f->sem); jffs2_complete_reservation(c); ret = jffs2_init_security(inode, dir_i, &dentry->d_name); if (ret) goto fail; ret = jffs2_init_acl_post(inode); if (ret) goto fail; ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen, ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen)); if (ret) goto fail; rd = jffs2_alloc_raw_dirent(); if (!rd) { /* Argh. Now we treat it like a normal delete */ jffs2_complete_reservation(c); ret = -ENOMEM; goto fail; } dir_f = JFFS2_INODE_INFO(dir_i); mutex_lock(&dir_f->sem); rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT); rd->totlen = cpu_to_je32(sizeof(*rd) + namelen); rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4)); rd->pino = cpu_to_je32(dir_i->i_ino); rd->version = cpu_to_je32(++dir_f->highest_version); rd->ino = cpu_to_je32(inode->i_ino); rd->mctime = cpu_to_je32(get_seconds()); rd->nsize = namelen; rd->type = DT_DIR; rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8)); rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen)); fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL); if (IS_ERR(fd)) { /* dirent failed to write. Delete the inode normally as if it were the final unlink() */ jffs2_complete_reservation(c); jffs2_free_raw_dirent(rd); mutex_unlock(&dir_f->sem); ret = PTR_ERR(fd); goto fail; } dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime)); inc_nlink(dir_i); jffs2_free_raw_dirent(rd); /* Link the fd into the inode's list, obsoleting an old one if necessary. */ jffs2_add_fd_to_list(c, fd, &dir_f->dents); mutex_unlock(&dir_f->sem); jffs2_complete_reservation(c); unlock_new_inode