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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/adfs/inode.c | |
download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/adfs/inode.c')
-rw-r--r-- | fs/adfs/inode.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c new file mode 100644 index 000000000000..a02802a30798 --- /dev/null +++ b/fs/adfs/inode.c @@ -0,0 +1,395 @@ +/* + * linux/fs/adfs/inode.c + * + * Copyright (C) 1997-1999 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/adfs_fs.h> +#include <linux/time.h> +#include <linux/stat.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/smp_lock.h> +#include <linux/module.h> +#include <linux/buffer_head.h> + +#include "adfs.h" + +/* + * Lookup/Create a block at offset 'block' into 'inode'. We currently do + * not support creation of new blocks, so we return -EIO for this case. + */ +static int +adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh, + int create) +{ + if (block < 0) + goto abort_negative; + + if (!create) { + if (block >= inode->i_blocks) + goto abort_toobig; + + block = __adfs_block_map(inode->i_sb, inode->i_ino, block); + if (block) + map_bh(bh, inode->i_sb, block); + return 0; + } + /* don't support allocation of blocks yet */ + return -EIO; + +abort_negative: + adfs_error(inode->i_sb, "block %d < 0", block); + return -EIO; + +abort_toobig: + return 0; +} + +static int adfs_writepage(struct page *page, struct writeback_control *wbc) +{ + return block_write_full_page(page, adfs_get_block, wbc); +} + +static int adfs_readpage(struct file *file, struct page *page) +{ + return block_read_full_page(page, adfs_get_block); +} + +static int adfs_prepare_write(struct file *file, struct page *page, unsigned int from, unsigned int to) +{ + return cont_prepare_write(page, from, to, adfs_get_block, + &ADFS_I(page->mapping->host)->mmu_private); +} + +static sector_t _adfs_bmap(struct address_space *mapping, sector_t block) +{ + return generic_block_bmap(mapping, block, adfs_get_block); +} + +static struct address_space_operations adfs_aops = { + .readpage = adfs_readpage, + .writepage = adfs_writepage, + .sync_page = block_sync_page, + .prepare_write = adfs_prepare_write, + .commit_write = generic_commit_write, + .bmap = _adfs_bmap +}; + +static inline unsigned int +adfs_filetype(struct inode *inode) +{ + unsigned int type; + + if (ADFS_I(inode)->stamped) + type = (ADFS_I(inode)->loadaddr >> 8) & 0xfff; + else + type = (unsigned int) -1; + + return type; +} + +/* + * Convert ADFS attributes and filetype to Linux permission. + */ +static umode_t +adfs_atts2mode(struct super_block *sb, struct inode *inode) +{ + unsigned int filetype, attr = ADFS_I(inode)->attr; + umode_t mode, rmask; + struct adfs_sb_info *asb = ADFS_SB(sb); + + if (attr & ADFS_NDA_DIRECTORY) { + mode = S_IRUGO & asb->s_owner_mask; + return S_IFDIR | S_IXUGO | mode; + } + + filetype = adfs_filetype(inode); + + switch (filetype) { + case 0xfc0: /* LinkFS */ + return S_IFLNK|S_IRWXUGO; + + case 0xfe6: /* UnixExec */ + rmask = S_IRUGO | S_IXUGO; + break; + + default: + rmask = S_IRUGO; + } + + mode = S_IFREG; + + if (attr & ADFS_NDA_OWNER_READ) + mode |= rmask & asb->s_owner_mask; + + if (attr & ADFS_NDA_OWNER_WRITE) + mode |= S_IWUGO & asb->s_owner_mask; + + if (attr & ADFS_NDA_PUBLIC_READ) + mode |= rmask & asb->s_other_mask; + + if (attr & ADFS_NDA_PUBLIC_WRITE) + mode |= S_IWUGO & asb->s_other_mask; + return mode; +} + +/* + * Convert Linux permission to ADFS attribute. We try to do the reverse + * of atts2mode, but there is not a 1:1 translation. + */ +static int +adfs_mode2atts(struct super_block *sb, struct inode *inode) +{ + umode_t mode; + int attr; + struct adfs_sb_info *asb = ADFS_SB(sb); + + /* FIXME: should we be able to alter a link? */ + if (S_ISLNK(inode->i_mode)) + return ADFS_I(inode)->attr; + + if (S_ISDIR(inode->i_mode)) + attr = ADFS_NDA_DIRECTORY; + else + attr = 0; + + mode = inode->i_mode & asb->s_owner_mask; + if (mode & S_IRUGO) + attr |= ADFS_NDA_OWNER_READ; + if (mode & S_IWUGO) + attr |= ADFS_NDA_OWNER_WRITE; + + mode = inode->i_mode & asb->s_other_mask; + mode &= ~asb->s_owner_mask; + if (mode & S_IRUGO) + attr |= ADFS_NDA_PUBLIC_READ; + if (mode & S_IWUGO) + attr |= ADFS_NDA_PUBLIC_WRITE; + + return attr; +} + +/* + * Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time + * referenced to 1 Jan 1900 (til 2248) + */ +static void +adfs_adfs2unix_time(struct timespec *tv, struct inode *inode) +{ + unsigned int high, low; + + if (ADFS_I(inode)->stamped == 0) + goto cur_time; + + high = ADFS_I(inode)->loadaddr << 24; + low = ADFS_I(inode)->execaddr; + + high |= low >> 8; + low &= 255; + + /* Files dated pre 01 Jan 1970 00:00:00. */ + if (high < 0x336e996a) + goto too_early; + + /* Files dated post 18 Jan 2038 03:14:05. */ + if (high >= 0x656e9969) + goto too_late; + + /* discard 2208988800 (0x336e996a00) seconds of time */ + high -= 0x336e996a; + + /* convert 40-bit centi-seconds to 32-bit seconds */ + tv->tv_sec = (((high % 100) << 8) + low) / 100 + (high / 100 << 8); + tv->tv_nsec = 0; + return; + + cur_time: + *tv = CURRENT_TIME_SEC; + return; + + too_early: + tv->tv_sec = tv->tv_nsec = 0; + return; + + too_late: + tv->tv_sec = 0x7ffffffd; + tv->tv_nsec = 0; + return; +} + +/* + * Convert an Unix time to ADFS time. We only do this if the entry has a + * time/date stamp already. + */ +static void +adfs_unix2adfs_time(struct inode *inode, unsigned int secs) +{ + unsigned int high, low; + + if (ADFS_I(inode)->stamped) { + /* convert 32-bit seconds to 40-bit centi-seconds */ + low = (secs & 255) * 100; + high = (secs / 256) * 100 + (low >> 8) + 0x336e996a; + + ADFS_I(inode)->loadaddr = (high >> 24) | + (ADFS_I(inode)->loadaddr & ~0xff); + ADFS_I(inode)->execaddr = (low & 255) | (high << 8); + } +} + +/* + * Fill in the inode information from the object information. + * + * Note that this is an inode-less filesystem, so we can't use the inode + * number to reference the metadata on the media. Instead, we use the + * inode number to hold the object ID, which in turn will tell us where + * the data is held. We also save the parent object ID, and with these + * two, we can locate the metadata. + * + * This does mean that we rely on an objects parent remaining the same at + * all times - we cannot cope with a cross-directory rename (yet). + */ +struct inode * +adfs_iget(struct super_block *sb, struct object_info *obj) +{ + struct inode *inode; + + inode = new_inode(sb); + if (!inode) + goto out; + + inode->i_uid = ADFS_SB(sb)->s_uid; + inode->i_gid = ADFS_SB(sb)->s_gid; + inode->i_ino = obj->file_id; + inode->i_size = obj->size; + inode->i_nlink = 2; + inode->i_blksize = PAGE_SIZE; + inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >> + sb->s_blocksize_bits; + + /* + * we need to save the parent directory ID so that + * write_inode can update the directory information + * for this file. This will need special handling + * for cross-directory renames. + */ + ADFS_I(inode)->parent_id = obj->parent_id; + ADFS_I(inode)->loadaddr = obj->loadaddr; + ADFS_I(inode)->execaddr = obj->execaddr; + ADFS_I(inode)->attr = obj->attr; + ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000); + + inode->i_mode = adfs_atts2mode(sb, inode); + adfs_adfs2unix_time(&inode->i_mtime, inode); + inode->i_atime = inode->i_mtime; + inode->i_ctime = inode->i_mtime; + + if (S_ISDIR(inode->i_mode)) { + inode->i_op = &adfs_dir_inode_operations; + inode->i_fop = &adfs_dir_operations; + } else if (S_ISREG(inode->i_mode)) { + inode->i_op = &adfs_file_inode_operations; + inode->i_fop = &adfs_file_operations; + inode->i_mapping->a_ops = &adfs_aops; + ADFS_I(inode)->mmu_private = inode->i_size; + } + + insert_inode_hash(inode); + +out: + return inode; +} + +/* + * Validate and convert a changed access mode/time to their ADFS equivalents. + * adfs_write_inode will actually write the information back to the directory + * later. + */ +int +adfs_notify_change(struct dentry *dentry, struct iattr *attr) +{ + struct inode *inode = dentry->d_inode; + struct super_block *sb = inode->i_sb; + unsigned int ia_valid = attr->ia_valid; + int error; + + lock_kernel(); + + error = inode_change_ok(inode, attr); + + /* + * we can't change the UID or GID of any file - + * we have a global UID/GID in the superblock + */ + if ((ia_valid & ATTR_UID && attr->ia_uid != ADFS_SB(sb)->s_uid) || + (ia_valid & ATTR_GID && attr->ia_gid != ADFS_SB(sb)->s_gid)) + error = -EPERM; + + if (error) + goto out; + + if (ia_valid & ATTR_SIZE) + error = vmtruncate(inode, attr->ia_size); + + if (error) + goto out; + + if (ia_valid & ATTR_MTIME) { + inode->i_mtime = attr->ia_mtime; + adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec); + } + /* + * FIXME: should we make these == to i_mtime since we don't + * have the ability to represent them in our filesystem? + */ + if (ia_valid & ATTR_ATIME) + inode->i_atime = attr->ia_atime; + if (ia_valid & ATTR_CTIME) + inode->i_ctime = attr->ia_ctime; + if (ia_valid & ATTR_MODE) { + ADFS_I(inode)->attr = adfs_mode2atts(sb, inode); + inode->i_mode = adfs_atts2mode(sb, inode); + } + + /* + * FIXME: should we be marking this inode dirty even if + * we don't have any metadata to write back? + */ + if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE)) + mark_inode_dirty(inode); +out: + unlock_kernel(); + return error; +} + +/* + * write an existing inode back to the directory, and therefore the disk. + * The adfs-specific inode data has already been updated by + * adfs_notify_change() + */ +int adfs_write_inode(struct inode *inode, int unused) +{ + struct super_block *sb = inode->i_sb; + struct object_info obj; + int ret; + + lock_kernel(); + obj.file_id = inode->i_ino; + obj.name_len = 0; + obj.parent_id = ADFS_I(inode)->parent_id; + obj.loadaddr = ADFS_I(inode)->loadaddr; + obj.execaddr = ADFS_I(inode)->execaddr; + obj.attr = ADFS_I(inode)->attr; + obj.size = inode->i_size; + + ret = adfs_dir_update(sb, &obj); + unlock_kernel(); + return ret; +} +MODULE_LICENSE("GPL"); |