?? fs.c
字號:
/* * JFFS2 -- Journalling Flash File System, Version 2. * * Copyright (C) 2001-2003 Red Hat, Inc. * * Created by David Woodhouse <dwmw2@redhat.com> * * For licensing information, see the file 'LICENCE' in this directory. * * $Id: fs.c,v 1.46 2004/07/13 08:56:54 dwmw2 Exp $ * */#include <linux/version.h>#include <linux/config.h>#include <linux/kernel.h>#include <linux/sched.h>#include <linux/fs.h>#include <linux/list.h>#include <linux/mtd/mtd.h>#include <linux/pagemap.h>#include <linux/slab.h>#include <linux/vfs.h>#include <linux/crc32.h>#include "nodelist.h"static int jffs2_do_setattr (struct inode *inode, struct iattr *iattr){ struct jffs2_full_dnode *old_metadata, *new_metadata; struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); struct jffs2_raw_inode *ri; unsigned short dev; unsigned char *mdata = NULL; int mdatalen = 0; unsigned int ivalid; uint32_t phys_ofs, alloclen; int ret; D1(printk(KERN_DEBUG "jffs2_setattr(): ino #%lu\n", inode->i_ino)); ret = inode_change_ok(inode, iattr); if (ret) return ret; /* Special cases - we don't want more than one data node for these types on the medium at any time. So setattr must read the original data associated with the node (i.e. the device numbers or the target name) and write it out again with the appropriate data attached */ if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) { /* For these, we don't actually need to read the old node */ dev = old_encode_dev(inode->i_rdev); mdata = (char *)&dev; mdatalen = sizeof(dev); D1(printk(KERN_DEBUG "jffs2_setattr(): Writing %d bytes of kdev_t\n", mdatalen)); } else if (S_ISLNK(inode->i_mode)) { mdatalen = f->metadata->size; mdata = kmalloc(f->metadata->size, GFP_USER); if (!mdata) return -ENOMEM; ret = jffs2_read_dnode(c, f, f->metadata, mdata, 0, mdatalen); if (ret) { kfree(mdata); return ret; } D1(printk(KERN_DEBUG "jffs2_setattr(): Writing %d bytes of symlink target\n", mdatalen)); } ri = jffs2_alloc_raw_inode(); if (!ri) { if (S_ISLNK(inode->i_mode)) kfree(mdata); return -ENOMEM; } ret = jffs2_reserve_space(c, sizeof(*ri) + mdatalen, &phys_ofs, &alloclen, ALLOC_NORMAL); if (ret) { jffs2_free_raw_inode(ri); if (S_ISLNK(inode->i_mode & S_IFMT)) kfree(mdata); return ret; } down(&f->sem); ivalid = iattr->ia_valid; ri->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); ri->nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE); ri->totlen = cpu_to_je32(sizeof(*ri) + mdatalen); ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4)); ri->ino = cpu_to_je32(inode->i_ino); ri->version = cpu_to_je32(++f->highest_version); ri->uid = cpu_to_je16((ivalid & ATTR_UID)?iattr->ia_uid:inode->i_uid); ri->gid = cpu_to_je16((ivalid & ATTR_GID)?iattr->ia_gid:inode->i_gid); if (ivalid & ATTR_MODE) if (iattr->ia_mode & S_ISGID && !in_group_p(je16_to_cpu(ri->gid)) && !capable(CAP_FSETID)) ri->mode = cpu_to_jemode(iattr->ia_mode & ~S_ISGID); else ri->mode = cpu_to_jemode(iattr->ia_mode); else ri->mode = cpu_to_jemode(inode->i_mode); ri->isize = cpu_to_je32((ivalid & ATTR_SIZE)?iattr->ia_size:inode->i_size); ri->atime = cpu_to_je32(I_SEC((ivalid & ATTR_ATIME)?iattr->ia_atime:inode->i_atime)); ri->mtime = cpu_to_je32(I_SEC((ivalid & ATTR_MTIME)?iattr->ia_mtime:inode->i_mtime)); ri->ctime = cpu_to_je32(I_SEC((ivalid & ATTR_CTIME)?iattr->ia_ctime:inode->i_ctime)); ri->offset = cpu_to_je32(0); ri->csize = ri->dsize = cpu_to_je32(mdatalen); ri->compr = JFFS2_COMPR_NONE; if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) { /* It's an extension. Make it a hole node */ ri->compr = JFFS2_COMPR_ZERO; ri->dsize = cpu_to_je32(iattr->ia_size - inode->i_size); ri->offset = cpu_to_je32(inode->i_size); } ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8)); if (mdatalen) ri->data_crc = cpu_to_je32(crc32(0, mdata, mdatalen)); else ri->data_crc = cpu_to_je32(0); new_metadata = jffs2_write_dnode(c, f, ri, mdata, mdatalen, phys_ofs, ALLOC_NORMAL); if (S_ISLNK(inode->i_mode)) kfree(mdata); if (IS_ERR(new_metadata)) { jffs2_complete_reservation(c); jffs2_free_raw_inode(ri); up(&f->sem); return PTR_ERR(new_metadata); } /* It worked. Update the inode */ inode->i_atime = ITIME(je32_to_cpu(ri->atime)); inode->i_ctime = ITIME(je32_to_cpu(ri->ctime)); inode->i_mtime = ITIME(je32_to_cpu(ri->mtime)); inode->i_mode = jemode_to_cpu(ri->mode); inode->i_uid = je16_to_cpu(ri->uid); inode->i_gid = je16_to_cpu(ri->gid); old_metadata = f->metadata; if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size) jffs2_truncate_fraglist (c, &f->fragtree, iattr->ia_size); if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) { jffs2_add_full_dnode_to_inode(c, f, new_metadata); inode->i_size = iattr->ia_size; f->metadata = NULL; } else { f->metadata = new_metadata; } if (old_metadata) { jffs2_mark_node_obsolete(c, old_metadata->raw); jffs2_free_full_dnode(old_metadata); } jffs2_free_raw_inode(ri); up(&f->sem); jffs2_complete_reservation(c); /* We have to do the vmtruncate() without f->sem held, since some pages may be locked and waiting for it in readpage(). We are protected from a simultaneous write() extending i_size back past iattr->ia_size, because do_truncate() holds the generic inode semaphore. */ if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size) vmtruncate(inode, iattr->ia_size); return 0;}int jffs2_setattr(struct dentry *dentry, struct iattr *iattr){ return jffs2_do_setattr(dentry->d_inode, iattr);}int jffs2_statfs(struct super_block *sb, struct kstatfs *buf){ struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); unsigned long avail; buf->f_type = JFFS2_SUPER_MAGIC; buf->f_bsize = 1 << PAGE_SHIFT; buf->f_blocks = c->flash_size >> PAGE_SHIFT; buf->f_files = 0; buf->f_ffree = 0; buf->f_namelen = JFFS2_MAX_NAME_LEN; spin_lock(&c->erase_completion_lock); avail = c->dirty_size + c->free_size; if (avail > c->sector_size * c->resv_blocks_write) avail -= c->sector_size * c->resv_blocks_write; else avail = 0; buf->f_bavail = buf->f_bfree = avail >> PAGE_SHIFT; D1(jffs2_dump_block_lists(c)); spin_unlock(&c->erase_completion_lock); return 0;}void jffs2_clear_inode (struct inode *inode){ /* We can forget about this inode for now - drop all * the nodelists associated with it, etc. */ struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); D1(printk(KERN_DEBUG "jffs2_clear_inode(): ino #%lu mode %o\n", inode->i_ino, inode->i_mode)); jffs2_do_clear_inode(c, f);}void jffs2_read_inode (struct inode *inode){ struct jffs2_inode_info *f; struct jffs2_sb_info *c; struct jffs2_raw_inode latest_node; int ret; D1(printk(KERN_DEBUG "jffs2_read_inode(): inode->i_ino == %lu\n", inode->i_ino)); f = JFFS2_INODE_INFO(inode); c = JFFS2_SB_INFO(inode->i_sb); jffs2_init_inode_info(f); ret = jffs2_do_read_inode(c, f, inode->i_ino, &latest_node); if (ret) { make_bad_inode(inode); up(&f->sem); return; } inode->i_mode = jemode_to_cpu(latest_node.mode); inode->i_uid = je16_to_cpu(latest_node.uid); inode->i_gid = je16_to_cpu(latest_node.gid); inode->i_size = je32_to_cpu(latest_node.isize); inode->i_atime = ITIME(je32_to_cpu(latest_node.atime)); inode->i_mtime = ITIME(je32_to_cpu(latest_node.mtime)); inode->i_ctime = ITIME(je32_to_cpu(latest_node.ctime)); inode->i_nlink = f->inocache->nlink; inode->i_blksize = PAGE_SIZE; inode->i_blocks = (inode->i_size + 511) >> 9; switch (inode->i_mode & S_IFMT) { jint16_t rdev; case S_IFLNK: inode->i_op = &jffs2_symlink_inode_operations; break; case S_IFDIR: { struct jffs2_full_dirent *fd; for (fd=f->dents; fd; fd = fd->next) { if (fd->type == DT_DIR && fd->ino) inode->i_nlink++; } /* and '..' */ inode->i_nlink++; /* Root dir gets i_nlink 3 for some reason */ if (inode->i_ino == 1) inode->i_nlink++; inode->i_op = &jffs2_dir_inode_operations; inode->i_fop = &jffs2_dir_operations; break; } case S_IFREG: 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; break; case S_IFBLK: case S_IFCHR: /* Read the device numbers from the media */ D1(printk(KERN_DEBUG "Reading device numbers from flash\n")); if (jffs2_read_dnode(c, f, f->metadata, (char *)&rdev, 0, sizeof(rdev)) < 0) { /* Eep */ printk(KERN_NOTICE "Read device numbers for inode %lu failed\n", (unsigned long)inode->i_ino); up(&f->sem); jffs2_do_clear_inode(c, f); make_bad_inode(inode); return; } case S_IFSOCK: case S_IFIFO: inode->i_op = &jffs2_file_inode_operations; init_special_inode(inode, inode->i_mode, old_decode_dev((je16_to_cpu(rdev)))); break; default: printk(KERN_WARNING "jffs2_read_inode(): Bogus imode %o for ino %lu\n", inode->i_mode, (unsigned long)inode->i_ino); } up(&f->sem); D1(printk(KERN_DEBUG "jffs2_read_inode() returning\n"));}void jffs2_dirty_inode(struct inode *inode){ struct iattr iattr; if (!(inode->i_state & I_DIRTY_DATASYNC)) { D2(printk(KERN_DEBUG "jffs2_dirty_inode() not calling setattr() for ino #%lu\n", inode->i_ino)); return; } D1(printk(KERN_DEBUG "jffs2_dirty_inode() calling setattr() for ino #%lu\n", inode->i_ino)); iattr.ia_valid = ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_MTIME|ATTR_CTIME;
?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -