linux/fs/minix/inode.c

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/*
* linux/fs/minix/inode.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* Copyright (C) 1996 Gertjan van Wingerde (gertjan@cs.vu.nl)
* Minix V2 fs support.
*
* Modified for 680x0 by Andreas Schwab
*/
#include <linux/module.h>
#include "minix.h"
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/highuid.h>
#include <linux/vfs.h>
static void minix_read_inode(struct inode * inode);
static int minix_write_inode(struct inode * inode, int wait);
static int minix_statfs(struct dentry *dentry, struct kstatfs *buf);
static int minix_remount (struct super_block * sb, int * flags, char * data);
static void minix_delete_inode(struct inode *inode)
{
truncate_inode_pages(&inode->i_data, 0);
inode->i_size = 0;
minix_truncate(inode);
minix_free_inode(inode);
}
static void minix_put_super(struct super_block *sb)
{
int i;
struct minix_sb_info *sbi = minix_sb(sb);
if (!(sb->s_flags & MS_RDONLY)) {
sbi->s_ms->s_state = sbi->s_mount_state;
mark_buffer_dirty(sbi->s_sbh);
}
for (i = 0; i < sbi->s_imap_blocks; i++)
brelse(sbi->s_imap[i]);
for (i = 0; i < sbi->s_zmap_blocks; i++)
brelse(sbi->s_zmap[i]);
brelse (sbi->s_sbh);
kfree(sbi->s_imap);
sb->s_fs_info = NULL;
kfree(sbi);
return;
}
static kmem_cache_t * minix_inode_cachep;
static struct inode *minix_alloc_inode(struct super_block *sb)
{
struct minix_inode_info *ei;
ei = (struct minix_inode_info *)kmem_cache_alloc(minix_inode_cachep, SLAB_KERNEL);
if (!ei)
return NULL;
return &ei->vfs_inode;
}
static void minix_destroy_inode(struct inode *inode)
{
kmem_cache_free(minix_inode_cachep, minix_i(inode));
}
static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
{
struct minix_inode_info *ei = (struct minix_inode_info *) foo;
if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
SLAB_CTOR_CONSTRUCTOR)
inode_init_once(&ei->vfs_inode);
}
static int init_inodecache(void)
{
minix_inode_cachep = kmem_cache_create("minix_inode_cache",
sizeof(struct minix_inode_info),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
init_once, NULL);
if (minix_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
static void destroy_inodecache(void)
{
if (kmem_cache_destroy(minix_inode_cachep))
printk(KERN_INFO "minix_inode_cache: not all structures were freed\n");
}
static struct super_operations minix_sops = {
.alloc_inode = minix_alloc_inode,
.destroy_inode = minix_destroy_inode,
.read_inode = minix_read_inode,
.write_inode = minix_write_inode,
.delete_inode = minix_delete_inode,
.put_super = minix_put_super,
.statfs = minix_statfs,
.remount_fs = minix_remount,
};
static int minix_remount (struct super_block * sb, int * flags, char * data)
{
struct minix_sb_info * sbi = minix_sb(sb);
struct minix_super_block * ms;
ms = sbi->s_ms;
if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
return 0;
if (*flags & MS_RDONLY) {
if (ms->s_state & MINIX_VALID_FS ||
!(sbi->s_mount_state & MINIX_VALID_FS))
return 0;
/* Mounting a rw partition read-only. */
ms->s_state = sbi->s_mount_state;
mark_buffer_dirty(sbi->s_sbh);
} else {
/* Mount a partition which is read-only, read-write. */
sbi->s_mount_state = ms->s_state;
ms->s_state &= ~MINIX_VALID_FS;
mark_buffer_dirty(sbi->s_sbh);
if (!(sbi->s_mount_state & MINIX_VALID_FS))
printk("MINIX-fs warning: remounting unchecked fs, "
"running fsck is recommended\n");
else if ((sbi->s_mount_state & MINIX_ERROR_FS))
printk("MINIX-fs warning: remounting fs with errors, "
"running fsck is recommended\n");
}
return 0;
}
static int minix_fill_super(struct super_block *s, void *data, int silent)
{
struct buffer_head *bh;
struct buffer_head **map;
struct minix_super_block *ms;
int i, block;
struct inode *root_inode;
struct minix_sb_info *sbi;
sbi = kmalloc(sizeof(struct minix_sb_info), GFP_KERNEL);
if (!sbi)
return -ENOMEM;
s->s_fs_info = sbi;
memset(sbi, 0, sizeof(struct minix_sb_info));
/* N.B. These should be compile-time tests.
Unfortunately that is impossible. */
if (32 != sizeof (struct minix_inode))
panic("bad V1 i-node size");
if (64 != sizeof(struct minix2_inode))
panic("bad V2 i-node size");
if (!sb_set_blocksize(s, BLOCK_SIZE))
goto out_bad_hblock;
if (!(bh = sb_bread(s, 1)))
goto out_bad_sb;
ms = (struct minix_super_block *) bh->b_data;
sbi->s_ms = ms;
sbi->s_sbh = bh;
sbi->s_mount_state = ms->s_state;
sbi->s_ninodes = ms->s_ninodes;
sbi->s_nzones = ms->s_nzones;
sbi->s_imap_blocks = ms->s_imap_blocks;
sbi->s_zmap_blocks = ms->s_zmap_blocks;
sbi->s_firstdatazone = ms->s_firstdatazone;
sbi->s_log_zone_size = ms->s_log_zone_size;
sbi->s_max_size = ms->s_max_size;
s->s_magic = ms->s_magic;
if (s->s_magic == MINIX_SUPER_MAGIC) {
sbi->s_version = MINIX_V1;
sbi->s_dirsize = 16;
sbi->s_namelen = 14;
sbi->s_link_max = MINIX_LINK_MAX;
} else if (s->s_magic == MINIX_SUPER_MAGIC2) {
sbi->s_version = MINIX_V1;
sbi->s_dirsize = 32;
sbi->s_namelen = 30;
sbi->s_link_max = MINIX_LINK_MAX;
} else if (s->s_magic == MINIX2_SUPER_MAGIC) {
sbi->s_version = MINIX_V2;
sbi->s_nzones = ms->s_zones;
sbi->s_dirsize = 16;
sbi->s_namelen = 14;
sbi->s_link_max = MINIX2_LINK_MAX;
} else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
sbi->s_version = MINIX_V2;
sbi->s_nzones = ms->s_zones;
sbi->s_dirsize = 32;
sbi->s_namelen = 30;
sbi->s_link_max = MINIX2_LINK_MAX;
} else
goto out_no_fs;
/*
* Allocate the buffer map to keep the superblock small.
*/
i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
map = kmalloc(i, GFP_KERNEL);
if (!map)
goto out_no_map;
memset(map, 0, i);
sbi->s_imap = &map[0];
sbi->s_zmap = &map[sbi->s_imap_blocks];
block=2;
for (i=0 ; i < sbi->s_imap_blocks ; i++) {
if (!(sbi->s_imap[i]=sb_bread(s, block)))
goto out_no_bitmap;
block++;
}
for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
if (!(sbi->s_zmap[i]=sb_bread(s, block)))
goto out_no_bitmap;
block++;
}
minix_set_bit(0,sbi->s_imap[0]->b_data);
minix_set_bit(0,sbi->s_zmap[0]->b_data);
/* set up enough so that it can read an inode */
s->s_op = &minix_sops;
root_inode = iget(s, MINIX_ROOT_INO);
if (!root_inode || is_bad_inode(root_inode))
goto out_no_root;
s->s_root = d_alloc_root(root_inode);
if (!s->s_root)
goto out_iput;
if (!NO_TRUNCATE)
s->s_root->d_op = &minix_dentry_operations;
if (!(s->s_flags & MS_RDONLY)) {
ms->s_state &= ~MINIX_VALID_FS;
mark_buffer_dirty(bh);
}
if (!(sbi->s_mount_state & MINIX_VALID_FS))
printk("MINIX-fs: mounting unchecked file system, "
"running fsck is recommended\n");
else if (sbi->s_mount_state & MINIX_ERROR_FS)
printk("MINIX-fs: mounting file system with errors, "
"running fsck is recommended\n");
return 0;
out_iput:
iput(root_inode);
goto out_freemap;
out_no_root:
if (!silent)
printk("MINIX-fs: get root inode failed\n");
goto out_freemap;
out_no_bitmap:
printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
out_freemap:
for (i = 0; i < sbi->s_imap_blocks; i++)
brelse(sbi->s_imap[i]);
for (i = 0; i < sbi->s_zmap_blocks; i++)
brelse(sbi->s_zmap[i]);
kfree(sbi->s_imap);
goto out_release;
out_no_map:
if (!silent)
printk("MINIX-fs: can't allocate map\n");
goto out_release;
out_no_fs:
if (!silent)
printk("VFS: Can't find a Minix or Minix V2 filesystem "
"on device %s\n", s->s_id);
out_release:
brelse(bh);
goto out;
out_bad_hblock:
printk("MINIX-fs: blocksize too small for device\n");
goto out;
out_bad_sb:
printk("MINIX-fs: unable to read superblock\n");
out:
s->s_fs_info = NULL;
kfree(sbi);
return -EINVAL;
}
static int minix_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct minix_sb_info *sbi = minix_sb(dentry->d_sb);
buf->f_type = dentry->d_sb->s_magic;
buf->f_bsize = dentry->d_sb->s_blocksize;
buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
buf->f_bfree = minix_count_free_blocks(sbi);
buf->f_bavail = buf->f_bfree;
buf->f_files = sbi->s_ninodes;
buf->f_ffree = minix_count_free_inodes(sbi);
buf->f_namelen = sbi->s_namelen;
return 0;
}
static int minix_get_block(struct inode *inode, sector_t block,
struct buffer_head *bh_result, int create)
{
if (INODE_VERSION(inode) == MINIX_V1)
return V1_minix_get_block(inode, block, bh_result, create);
else
return V2_minix_get_block(inode, block, bh_result, create);
}
static int minix_writepage(struct page *page, struct writeback_control *wbc)
{
return block_write_full_page(page, minix_get_block, wbc);
}
static int minix_readpage(struct file *file, struct page *page)
{
return block_read_full_page(page,minix_get_block);
}
static int minix_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
{
return block_prepare_write(page,from,to,minix_get_block);
}
static sector_t minix_bmap(struct address_space *mapping, sector_t block)
{
return generic_block_bmap(mapping,block,minix_get_block);
}
static const struct address_space_operations minix_aops = {
.readpage = minix_readpage,
.writepage = minix_writepage,
.sync_page = block_sync_page,
.prepare_write = minix_prepare_write,
.commit_write = generic_commit_write,
.bmap = minix_bmap
};
static struct inode_operations minix_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = page_follow_link_light,
.put_link = page_put_link,
.getattr = minix_getattr,
};
void minix_set_inode(struct inode *inode, dev_t rdev)
{
if (S_ISREG(inode->i_mode)) {
inode->i_op = &minix_file_inode_operations;
inode->i_fop = &minix_file_operations;
inode->i_mapping->a_ops = &minix_aops;
} else if (S_ISDIR(inode->i_mode)) {
inode->i_op = &minix_dir_inode_operations;
inode->i_fop = &minix_dir_operations;
inode->i_mapping->a_ops = &minix_aops;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &minix_symlink_inode_operations;
inode->i_mapping->a_ops = &minix_aops;
} else
init_special_inode(inode, inode->i_mode, rdev);
}
/*
* The minix V1 function to read an inode.
*/
static void V1_minix_read_inode(struct inode * inode)
{
struct buffer_head * bh;
struct minix_inode * raw_inode;
struct minix_inode_info *minix_inode = minix_i(inode);
int i;
raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
if (!raw_inode) {
make_bad_inode(inode);
return;
}
inode->i_mode = raw_inode->i_mode;
inode->i_uid = (uid_t)raw_inode->i_uid;
inode->i_gid = (gid_t)raw_inode->i_gid;
inode->i_nlink = raw_inode->i_nlinks;
inode->i_size = raw_inode->i_size;
inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time;
inode->i_mtime.tv_nsec = 0;
inode->i_atime.tv_nsec = 0;
inode->i_ctime.tv_nsec = 0;
inode->i_blocks = inode->i_blksize = 0;
for (i = 0; i < 9; i++)
minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
brelse(bh);
}
/*
* The minix V2 function to read an inode.
*/
static void V2_minix_read_inode(struct inode * inode)
{
struct buffer_head * bh;
struct minix2_inode * raw_inode;
struct minix_inode_info *minix_inode = minix_i(inode);
int i;
raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
if (!raw_inode) {
make_bad_inode(inode);
return;
}
inode->i_mode = raw_inode->i_mode;
inode->i_uid = (uid_t)raw_inode->i_uid;
inode->i_gid = (gid_t)raw_inode->i_gid;
inode->i_nlink = raw_inode->i_nlinks;
inode->i_size = raw_inode->i_size;
inode->i_mtime.tv_sec = raw_inode->i_mtime;
inode->i_atime.tv_sec = raw_inode->i_atime;
inode->i_ctime.tv_sec = raw_inode->i_ctime;
inode->i_mtime.tv_nsec = 0;
inode->i_atime.tv_nsec = 0;
inode->i_ctime.tv_nsec = 0;
inode->i_blocks = inode->i_blksize = 0;
for (i = 0; i < 10; i++)
minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
brelse(bh);
}
/*
* The global function to read an inode.
*/
static void minix_read_inode(struct inode * inode)
{
if (INODE_VERSION(inode) == MINIX_V1)
V1_minix_read_inode(inode);
else
V2_minix_read_inode(inode);
}
/*
* The minix V1 function to synchronize an inode.
*/
static struct buffer_head * V1_minix_update_inode(struct inode * inode)
{
struct buffer_head * bh;
struct minix_inode * raw_inode;
struct minix_inode_info *minix_inode = minix_i(inode);
int i;
raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
if (!raw_inode)
return NULL;
raw_inode->i_mode = inode->i_mode;
raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
raw_inode->i_nlinks = inode->i_nlink;
raw_inode->i_size = inode->i_size;
raw_inode->i_time = inode->i_mtime.tv_sec;
if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
else for (i = 0; i < 9; i++)
raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
mark_buffer_dirty(bh);
return bh;
}
/*
* The minix V2 function to synchronize an inode.
*/
static struct buffer_head * V2_minix_update_inode(struct inode * inode)
{
struct buffer_head * bh;
struct minix2_inode * raw_inode;
struct minix_inode_info *minix_inode = minix_i(inode);
int i;
raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
if (!raw_inode)
return NULL;
raw_inode->i_mode = inode->i_mode;
raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
raw_inode->i_nlinks = inode->i_nlink;
raw_inode->i_size = inode->i_size;
raw_inode->i_mtime = inode->i_mtime.tv_sec;
raw_inode->i_atime = inode->i_atime.tv_sec;
raw_inode->i_ctime = inode->i_ctime.tv_sec;
if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
else for (i = 0; i < 10; i++)
raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
mark_buffer_dirty(bh);
return bh;
}
static struct buffer_head *minix_update_inode(struct inode *inode)
{
if (INODE_VERSION(inode) == MINIX_V1)
return V1_minix_update_inode(inode);
else
return V2_minix_update_inode(inode);
}
static int minix_write_inode(struct inode * inode, int wait)
{
brelse(minix_update_inode(inode));
return 0;
}
int minix_sync_inode(struct inode * inode)
{
int err = 0;
struct buffer_head *bh;
bh = minix_update_inode(inode);
if (bh && buffer_dirty(bh))
{
sync_dirty_buffer(bh);
if (buffer_req(bh) && !buffer_uptodate(bh))
{
printk("IO error syncing minix inode [%s:%08lx]\n",
inode->i_sb->s_id, inode->i_ino);
err = -1;
}
}
else if (!bh)
err = -1;
brelse (bh);
return err;
}
int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
generic_fillattr(dentry->d_inode, stat);
if (INODE_VERSION(dentry->d_inode) == MINIX_V1)
stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size);
else
stat->blocks = (BLOCK_SIZE / 512) * V2_minix_blocks(stat->size);
stat->blksize = BLOCK_SIZE;
return 0;
}
/*
* The function that is called for file truncation.
*/
void minix_truncate(struct inode * inode)
{
if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
return;
if (INODE_VERSION(inode) == MINIX_V1)
V1_minix_truncate(inode);
else
V2_minix_truncate(inode);
}
[PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 09:02:57 +00:00
static int minix_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
[PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 09:02:57 +00:00
return get_sb_bdev(fs_type, flags, dev_name, data, minix_fill_super,
mnt);
}
static struct file_system_type minix_fs_type = {
.owner = THIS_MODULE,
.name = "minix",
.get_sb = minix_get_sb,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
static int __init init_minix_fs(void)
{
int err = init_inodecache();
if (err)
goto out1;
err = register_filesystem(&minix_fs_type);
if (err)
goto out;
return 0;
out:
destroy_inodecache();
out1:
return err;
}
static void __exit exit_minix_fs(void)
{
unregister_filesystem(&minix_fs_type);
destroy_inodecache();
}
module_init(init_minix_fs)
module_exit(exit_minix_fs)
MODULE_LICENSE("GPL");