jsauer/torvalds-linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-01-11 17:10:13 +00:00
Code
torvalds-linux/fs/hfs/inode.c
Linus Torvalds 7031769e10 vfs-6.17-rc1.mmap_prepare 
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCaINCgQAKCRCRxhvAZXjc
 os+nAP9LFHUwWO6EBzHJJGEVjJvvzsbzqeYrRFamYiMc5ulPJwD+KW4RIgJa/MWO
 pcYE40CacaekD8rFWwYUyszpgmv6ewc=
 =wCwp
 -----END PGP SIGNATURE-----

Merge tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull mmap_prepare updates from Christian Brauner:
 "Last cycle we introduce f_op->mmap_prepare() in c84bf6dd2b83 ("mm:
  introduce new .mmap_prepare() file callback").

  This is preferred to the existing f_op->mmap() hook as it does require
  a VMA to be established yet, thus allowing the mmap logic to invoke
  this hook far, far earlier, prior to inserting a VMA into the virtual
  address space, or performing any other heavy handed operations.

  This allows for much simpler unwinding on error, and for there to be a
  single attempt at merging a VMA rather than having to possibly
  reattempt a merge based on potentially altered VMA state.

  Far more importantly, it prevents inappropriate manipulation of
  incompletely initialised VMA state, which is something that has been
  the cause of bugs and complexity in the past.

  The intent is to gradually deprecate f_op->mmap, and in that vein this
  series coverts the majority of file systems to using f_op->mmap_prepare.

  Prerequisite steps are taken - firstly ensuring all checks for mmap
  capabilities use the file_has_valid_mmap_hooks() helper rather than
  directly checking for f_op->mmap (which is now not a valid check) and
  secondly updating daxdev_mapping_supported() to not require a VMA
  parameter to allow ext4 and xfs to be converted.

  Commit bb666b7c2707 ("mm: add mmap_prepare() compatibility layer for
  nested file systems") handles the nasty edge-case of nested file
  systems like overlayfs, which introduces a compatibility shim to allow
  f_op->mmap_prepare() to be invoked from an f_op->mmap() callback.

  This allows for nested filesystems to continue to function correctly
  with all file systems regardless of which callback is used. Once we
  finally convert all file systems, this shim can be removed.

  As a result, ecryptfs, fuse, and overlayfs remain unaltered so they
  can nest all other file systems.

  We additionally do not update resctl - as this requires an update to
  remap_pfn_range() (or an alternative to it) which we defer to a later
  series, equally we do not update cramfs which needs a mixed mapping
  insertion with the same issue, nor do we update procfs, hugetlbfs,
  syfs or kernfs all of which require VMAs for internal state and hooks.
  We shall return to all of these later"

* tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  doc: update porting, vfs documentation to describe mmap_prepare()
  fs: replace mmap hook with .mmap_prepare for simple mappings
  fs: convert most other generic_file_*mmap() users to .mmap_prepare()
  fs: convert simple use of generic_file_*_mmap() to .mmap_prepare()
  mm/filemap: introduce generic_file_*_mmap_prepare() helpers
  fs/xfs: transition from deprecated .mmap hook to .mmap_prepare
  fs/ext4: transition from deprecated .mmap hook to .mmap_prepare
  fs/dax: make it possible to check dev dax support without a VMA
  fs: consistently use can_mmap_file() helper
  mm/nommu: use file_has_valid_mmap_hooks() helper
  mm: rename call_mmap/mmap_prepare to vfs_mmap/mmap_prepare
2025-07-28 13:43:25 -07:00

705 lines
19 KiB
C
Raw Blame History

/*
* linux/fs/hfs/inode.c
*
* Copyright (C) 1995-1997 Paul H. Hargrove
* (C) 2003 Ardis Technologies <roman@ardistech.com>
* This file may be distributed under the terms of the GNU General Public License.
*
* This file contains inode-related functions which do not depend on
* which scheme is being used to represent forks.
*
* Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
*/
#include <linux/pagemap.h>
#include <linux/mpage.h>
#include <linux/sched.h>
#include <linux/cred.h>
#include <linux/uio.h>
#include <linux/xattr.h>
#include <linux/blkdev.h>
#include "hfs_fs.h"
#include "btree.h"
static const struct file_operations hfs_file_operations;
static const struct inode_operations hfs_file_inode_operations;
/*================ Variable-like macros ================*/
#define HFS_VALID_MODE_BITS (S_IFREG | S_IFDIR | S_IRWXUGO)
static int hfs_read_folio(struct file *file, struct folio *folio)
{
return block_read_full_folio(folio, hfs_get_block);
}
static void hfs_write_failed(struct address_space *mapping, loff_t to)
{
struct inode *inode = mapping->host;
if (to > inode->i_size) {
truncate_pagecache(inode, inode->i_size);
hfs_file_truncate(inode);
}
}
int hfs_write_begin(const struct kiocb *iocb, struct address_space *mapping,
loff_t pos, unsigned len, struct folio **foliop, void **fsdata)
{
int ret;
ret = cont_write_begin(iocb, mapping, pos, len, foliop, fsdata,
hfs_get_block,
&HFS_I(mapping->host)->phys_size);
if (unlikely(ret))
hfs_write_failed(mapping, pos + len);
return ret;
}
static sector_t hfs_bmap(struct address_space *mapping, sector_t block)
{
return generic_block_bmap(mapping, block, hfs_get_block);
}
static bool hfs_release_folio(struct folio *folio, gfp_t mask)
{
struct inode *inode = folio->mapping->host;
struct super_block *sb = inode->i_sb;
struct hfs_btree *tree;
struct hfs_bnode *node;
u32 nidx;
int i;
bool res = true;
switch (inode->i_ino) {
case HFS_EXT_CNID:
tree = HFS_SB(sb)->ext_tree;
break;
case HFS_CAT_CNID:
tree = HFS_SB(sb)->cat_tree;
break;
default:
BUG();
return false;
}
if (!tree)
return false;
if (tree->node_size >= PAGE_SIZE) {
nidx = folio->index >> (tree->node_size_shift - PAGE_SHIFT);
spin_lock(&tree->hash_lock);
node = hfs_bnode_findhash(tree, nidx);
if (!node)
;
else if (atomic_read(&node->refcnt))
res = false;
if (res && node) {
hfs_bnode_unhash(node);
hfs_bnode_free(node);
}
spin_unlock(&tree->hash_lock);
} else {
nidx = folio->index << (PAGE_SHIFT - tree->node_size_shift);
i = 1 << (PAGE_SHIFT - tree->node_size_shift);
spin_lock(&tree->hash_lock);
do {
node = hfs_bnode_findhash(tree, nidx++);
if (!node)
continue;
if (atomic_read(&node->refcnt)) {
res = false;
break;
}
hfs_bnode_unhash(node);
hfs_bnode_free(node);
} while (--i && nidx < tree->node_count);
spin_unlock(&tree->hash_lock);
}
return res ? try_to_free_buffers(folio) : false;
}
static ssize_t hfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
size_t count = iov_iter_count(iter);
ssize_t ret;
ret = blockdev_direct_IO(iocb, inode, iter, hfs_get_block);
/*
* In case of error extending write may have instantiated a few
* blocks outside i_size. Trim these off again.
*/
if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
loff_t isize = i_size_read(inode);
loff_t end = iocb->ki_pos + count;
if (end > isize)
hfs_write_failed(mapping, end);
}
return ret;
}
static int hfs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
return mpage_writepages(mapping, wbc, hfs_get_block);
}
const struct address_space_operations hfs_btree_aops = {
.dirty_folio = block_dirty_folio,
.invalidate_folio = block_invalidate_folio,
.read_folio = hfs_read_folio,
.writepages = hfs_writepages,
.write_begin = hfs_write_begin,
.write_end = generic_write_end,
.migrate_folio = buffer_migrate_folio,
.bmap = hfs_bmap,
.release_folio = hfs_release_folio,
};
const struct address_space_operations hfs_aops = {
.dirty_folio = block_dirty_folio,
.invalidate_folio = block_invalidate_folio,
.read_folio = hfs_read_folio,
.write_begin = hfs_write_begin,
.write_end = generic_write_end,
.bmap = hfs_bmap,
.direct_IO = hfs_direct_IO,
.writepages = hfs_writepages,
.migrate_folio = buffer_migrate_folio,
};
/*
* hfs_new_inode
*/
struct inode *hfs_new_inode(struct inode *dir, const struct qstr *name, umode_t mode)
{
struct super_block *sb = dir->i_sb;
struct inode *inode = new_inode(sb);
if (!inode)
return NULL;
mutex_init(&HFS_I(inode)->extents_lock);
INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
spin_lock_init(&HFS_I(inode)->open_dir_lock);
hfs_cat_build_key(sb, (btree_key *)&HFS_I(inode)->cat_key, dir->i_ino, name);
inode->i_ino = HFS_SB(sb)->next_id++;
inode->i_mode = mode;
inode->i_uid = current_fsuid();
inode->i_gid = current_fsgid();
set_nlink(inode, 1);
simple_inode_init_ts(inode);
HFS_I(inode)->flags = 0;
HFS_I(inode)->rsrc_inode = NULL;
HFS_I(inode)->fs_blocks = 0;
HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;
if (S_ISDIR(mode)) {
inode->i_size = 2;
HFS_SB(sb)->folder_count++;
if (dir->i_ino == HFS_ROOT_CNID)
HFS_SB(sb)->root_dirs++;
inode->i_op = &hfs_dir_inode_operations;
inode->i_fop = &hfs_dir_operations;
inode->i_mode |= S_IRWXUGO;
inode->i_mode &= ~HFS_SB(inode->i_sb)->s_dir_umask;
} else if (S_ISREG(mode)) {
HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
HFS_SB(sb)->file_count++;
if (dir->i_ino == HFS_ROOT_CNID)
HFS_SB(sb)->root_files++;
inode->i_op = &hfs_file_inode_operations;
inode->i_fop = &hfs_file_operations;
inode->i_mapping->a_ops = &hfs_aops;
inode->i_mode |= S_IRUGO|S_IXUGO;
if (mode & S_IWUSR)
inode->i_mode |= S_IWUGO;
inode->i_mode &= ~HFS_SB(inode->i_sb)->s_file_umask;
HFS_I(inode)->phys_size = 0;
HFS_I(inode)->alloc_blocks = 0;
HFS_I(inode)->first_blocks = 0;
HFS_I(inode)->cached_start = 0;
HFS_I(inode)->cached_blocks = 0;
memset(HFS_I(inode)->first_extents, 0, sizeof(hfs_extent_rec));
memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
}
insert_inode_hash(inode);
mark_inode_dirty(inode);
set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
hfs_mark_mdb_dirty(sb);
return inode;
}
void hfs_delete_inode(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
hfs_dbg(INODE, "delete_inode: %lu\n", inode->i_ino);
if (S_ISDIR(inode->i_mode)) {
HFS_SB(sb)->folder_count--;
if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
HFS_SB(sb)->root_dirs--;
set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
hfs_mark_mdb_dirty(sb);
return;
}
HFS_SB(sb)->file_count--;
if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
HFS_SB(sb)->root_files--;
if (S_ISREG(inode->i_mode)) {
if (!inode->i_nlink) {
inode->i_size = 0;
hfs_file_truncate(inode);
}
}
set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
hfs_mark_mdb_dirty(sb);
}
void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext,
__be32 __log_size, __be32 phys_size, u32 clump_size)
{
struct super_block *sb = inode->i_sb;
u32 log_size = be32_to_cpu(__log_size);
u16 count;
int i;
memcpy(HFS_I(inode)->first_extents, ext, sizeof(hfs_extent_rec));
for (count = 0, i = 0; i < 3; i++)
count += be16_to_cpu(ext[i].count);
HFS_I(inode)->first_blocks = count;
HFS_I(inode)->cached_start = 0;
HFS_I(inode)->cached_blocks = 0;
inode->i_size = HFS_I(inode)->phys_size = log_size;
HFS_I(inode)->fs_blocks = (log_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
HFS_I(inode)->alloc_blocks = be32_to_cpu(phys_size) /
HFS_SB(sb)->alloc_blksz;
HFS_I(inode)->clump_blocks = clump_size / HFS_SB(sb)->alloc_blksz;
if (!HFS_I(inode)->clump_blocks)
HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
}
struct hfs_iget_data {
struct hfs_cat_key *key;
hfs_cat_rec *rec;
};
static int hfs_test_inode(struct inode *inode, void *data)
{
struct hfs_iget_data *idata = data;
hfs_cat_rec *rec;
rec = idata->rec;
switch (rec->type) {
case HFS_CDR_DIR:
return inode->i_ino == be32_to_cpu(rec->dir.DirID);
case HFS_CDR_FIL:
return inode->i_ino == be32_to_cpu(rec->file.FlNum);
default:
BUG();
return 1;
}
}
/*
* hfs_read_inode
*/
static int hfs_read_inode(struct inode *inode, void *data)
{
struct hfs_iget_data *idata = data;
struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
hfs_cat_rec *rec;
HFS_I(inode)->flags = 0;
HFS_I(inode)->rsrc_inode = NULL;
mutex_init(&HFS_I(inode)->extents_lock);
INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
spin_lock_init(&HFS_I(inode)->open_dir_lock);
/* Initialize the inode */
inode->i_uid = hsb->s_uid;
inode->i_gid = hsb->s_gid;
set_nlink(inode, 1);
if (idata->key)
HFS_I(inode)->cat_key = *idata->key;
else
HFS_I(inode)->flags |= HFS_FLG_RSRC;
HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;
rec = idata->rec;
switch (rec->type) {
case HFS_CDR_FIL:
if (!HFS_IS_RSRC(inode)) {
hfs_inode_read_fork(inode, rec->file.ExtRec, rec->file.LgLen,
rec->file.PyLen, be16_to_cpu(rec->file.ClpSize));
} else {
hfs_inode_read_fork(inode, rec->file.RExtRec, rec->file.RLgLen,
rec->file.RPyLen, be16_to_cpu(rec->file.ClpSize));
}
inode->i_ino = be32_to_cpu(rec->file.FlNum);
inode->i_mode = S_IRUGO | S_IXUGO;
if (!(rec->file.Flags & HFS_FIL_LOCK))
inode->i_mode |= S_IWUGO;
inode->i_mode &= ~hsb->s_file_umask;
inode->i_mode |= S_IFREG;
inode_set_mtime_to_ts(inode,
inode_set_atime_to_ts(inode, inode_set_ctime_to_ts(inode, hfs_m_to_utime(rec->file.MdDat))));
inode->i_op = &hfs_file_inode_operations;
inode->i_fop = &hfs_file_operations;
inode->i_mapping->a_ops = &hfs_aops;
break;
case HFS_CDR_DIR:
inode->i_ino = be32_to_cpu(rec->dir.DirID);
inode->i_size = be16_to_cpu(rec->dir.Val) + 2;
HFS_I(inode)->fs_blocks = 0;
inode->i_mode = S_IFDIR | (S_IRWXUGO & ~hsb->s_dir_umask);
inode_set_mtime_to_ts(inode,
inode_set_atime_to_ts(inode, inode_set_ctime_to_ts(inode, hfs_m_to_utime(rec->dir.MdDat))));
inode->i_op = &hfs_dir_inode_operations;
inode->i_fop = &hfs_dir_operations;
break;
default:
make_bad_inode(inode);
}
return 0;
}
/*
* __hfs_iget()
*
* Given the MDB for a HFS filesystem, a 'key' and an 'entry' in
* the catalog B-tree and the 'type' of the desired file return the
* inode for that file/directory or NULL. Note that 'type' indicates
* whether we want the actual file or directory, or the corresponding
* metadata (AppleDouble header file or CAP metadata file).
*/
struct inode *hfs_iget(struct super_block *sb, struct hfs_cat_key *key, hfs_cat_rec *rec)
{
struct hfs_iget_data data = { key, rec };
struct inode *inode;
u32 cnid;
switch (rec->type) {
case HFS_CDR_DIR:
cnid = be32_to_cpu(rec->dir.DirID);
break;
case HFS_CDR_FIL:
cnid = be32_to_cpu(rec->file.FlNum);
break;
default:
return NULL;
}
inode = iget5_locked(sb, cnid, hfs_test_inode, hfs_read_inode, &data);
if (inode && (inode->i_state & I_NEW))
unlock_new_inode(inode);
return inode;
}
void hfs_inode_write_fork(struct inode *inode, struct hfs_extent *ext,
__be32 *log_size, __be32 *phys_size)
{
memcpy(ext, HFS_I(inode)->first_extents, sizeof(hfs_extent_rec));
if (log_size)
*log_size = cpu_to_be32(inode->i_size);
if (phys_size)
*phys_size = cpu_to_be32(HFS_I(inode)->alloc_blocks *
HFS_SB(inode->i_sb)->alloc_blksz);
}
int hfs_write_inode(struct inode *inode, struct writeback_control *wbc)
{
struct inode *main_inode = inode;
struct hfs_find_data fd;
hfs_cat_rec rec;
int res;
hfs_dbg(INODE, "hfs_write_inode: %lu\n", inode->i_ino);
res = hfs_ext_write_extent(inode);
if (res)
return res;
if (inode->i_ino < HFS_FIRSTUSER_CNID) {
switch (inode->i_ino) {
case HFS_ROOT_CNID:
break;
case HFS_EXT_CNID:
hfs_btree_write(HFS_SB(inode->i_sb)->ext_tree);
return 0;
case HFS_CAT_CNID:
hfs_btree_write(HFS_SB(inode->i_sb)->cat_tree);
return 0;
default:
BUG();
return -EIO;
}
}
if (HFS_IS_RSRC(inode))
main_inode = HFS_I(inode)->rsrc_inode;
if (!main_inode->i_nlink)
return 0;
if (hfs_find_init(HFS_SB(main_inode->i_sb)->cat_tree, &fd))
/* panic? */
return -EIO;
res = -EIO;
if (HFS_I(main_inode)->cat_key.CName.len > HFS_NAMELEN)
goto out;
fd.search_key->cat = HFS_I(main_inode)->cat_key;
if (hfs_brec_find(&fd))
goto out;
if (S_ISDIR(main_inode->i_mode)) {
if (fd.entrylength < sizeof(struct hfs_cat_dir))
goto out;
hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
sizeof(struct hfs_cat_dir));
if (rec.type != HFS_CDR_DIR ||
be32_to_cpu(rec.dir.DirID) != inode->i_ino) {
}
rec.dir.MdDat = hfs_u_to_mtime(inode_get_mtime(inode));
rec.dir.Val = cpu_to_be16(inode->i_size - 2);
hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
sizeof(struct hfs_cat_dir));
} else if (HFS_IS_RSRC(inode)) {
if (fd.entrylength < sizeof(struct hfs_cat_file))
goto out;
hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
sizeof(struct hfs_cat_file));
hfs_inode_write_fork(inode, rec.file.RExtRec,
&rec.file.RLgLen, &rec.file.RPyLen);
hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
sizeof(struct hfs_cat_file));
} else {
if (fd.entrylength < sizeof(struct hfs_cat_file))
goto out;
hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
sizeof(struct hfs_cat_file));
if (rec.type != HFS_CDR_FIL ||
be32_to_cpu(rec.file.FlNum) != inode->i_ino) {
}
if (inode->i_mode & S_IWUSR)
rec.file.Flags &= ~HFS_FIL_LOCK;
else
rec.file.Flags |= HFS_FIL_LOCK;
hfs_inode_write_fork(inode, rec.file.ExtRec, &rec.file.LgLen, &rec.file.PyLen);
rec.file.MdDat = hfs_u_to_mtime(inode_get_mtime(inode));
hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
sizeof(struct hfs_cat_file));
}
res = 0;
out:
hfs_find_exit(&fd);
return res;
}
static struct dentry *hfs_file_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct inode *inode = NULL;
hfs_cat_rec rec;
struct hfs_find_data fd;
int res;
if (HFS_IS_RSRC(dir) || strcmp(dentry->d_name.name, "rsrc"))
goto out;
inode = HFS_I(dir)->rsrc_inode;
if (inode)
goto out;
inode = new_inode(dir->i_sb);
if (!inode)
return ERR_PTR(-ENOMEM);
res = hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
if (res) {
iput(inode);
return ERR_PTR(res);
}
fd.search_key->cat = HFS_I(dir)->cat_key;
res = hfs_brec_read(&fd, &rec, sizeof(rec));
if (!res) {
struct hfs_iget_data idata = { NULL, &rec };
hfs_read_inode(inode, &idata);
}
hfs_find_exit(&fd);
if (res) {
iput(inode);
return ERR_PTR(res);
}
HFS_I(inode)->rsrc_inode = dir;
HFS_I(dir)->rsrc_inode = inode;
igrab(dir);
inode_fake_hash(inode);
mark_inode_dirty(inode);
dont_mount(dentry);
out:
return d_splice_alias(inode, dentry);
}
void hfs_evict_inode(struct inode *inode)
{
truncate_inode_pages_final(&inode->i_data);
clear_inode(inode);
if (HFS_IS_RSRC(inode) && HFS_I(inode)->rsrc_inode) {
HFS_I(HFS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
iput(HFS_I(inode)->rsrc_inode);
}
}
static int hfs_file_open(struct inode *inode, struct file *file)
{
if (HFS_IS_RSRC(inode))
inode = HFS_I(inode)->rsrc_inode;
atomic_inc(&HFS_I(inode)->opencnt);
return 0;
}
static int hfs_file_release(struct inode *inode, struct file *file)
{
//struct super_block *sb = inode->i_sb;
if (HFS_IS_RSRC(inode))
inode = HFS_I(inode)->rsrc_inode;
if (atomic_dec_and_test(&HFS_I(inode)->opencnt)) {
inode_lock(inode);
hfs_file_truncate(inode);
//if (inode->i_flags & S_DEAD) {
// hfs_delete_cat(inode->i_ino, HFSPLUS_SB(sb).hidden_dir, NULL);
// hfs_delete_inode(inode);
//}
inode_unlock(inode);
}
return 0;
}
/*
* hfs_notify_change()
*
* Based very closely on fs/msdos/inode.c by Werner Almesberger
*
* This is the notify_change() field in the super_operations structure
* for HFS file systems. The purpose is to take that changes made to
* an inode and apply then in a filesystem-dependent manner. In this
* case the process has a few of tasks to do:
* 1) prevent changes to the i_uid and i_gid fields.
* 2) map file permissions to the closest allowable permissions
* 3) Since multiple Linux files can share the same on-disk inode under
* HFS (for instance the data and resource forks of a file) a change
* to permissions must be applied to all other in-core inodes which
* correspond to the same HFS file.
*/
int hfs_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
struct iattr *attr)
{
struct inode *inode = d_inode(dentry);
struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
int error;
error = setattr_prepare(&nop_mnt_idmap, dentry,
attr); /* basic permission checks */
if (error)
return error;
/* no uig/gid changes and limit which mode bits can be set */
if (((attr->ia_valid & ATTR_UID) &&
(!uid_eq(attr->ia_uid, hsb->s_uid))) ||
((attr->ia_valid & ATTR_GID) &&
(!gid_eq(attr->ia_gid, hsb->s_gid))) ||
((attr->ia_valid & ATTR_MODE) &&
((S_ISDIR(inode->i_mode) &&
(attr->ia_mode != inode->i_mode)) ||
(attr->ia_mode & ~HFS_VALID_MODE_BITS)))) {
return hsb->s_quiet ? 0 : error;
}
if (attr->ia_valid & ATTR_MODE) {
/* Only the 'w' bits can ever change and only all together. */
if (attr->ia_mode & S_IWUSR)
attr->ia_mode = inode->i_mode | S_IWUGO;
else
attr->ia_mode = inode->i_mode & ~S_IWUGO;
attr->ia_mode &= S_ISDIR(inode->i_mode) ? ~hsb->s_dir_umask: ~hsb->s_file_umask;
}
if ((attr->ia_valid & ATTR_SIZE) &&
attr->ia_size != i_size_read(inode)) {
inode_dio_wait(inode);
error = inode_newsize_ok(inode, attr->ia_size);
if (error)
return error;
truncate_setsize(inode, attr->ia_size);
hfs_file_truncate(inode);
simple_inode_init_ts(inode);
}
setattr_copy(&nop_mnt_idmap, inode, attr);
mark_inode_dirty(inode);
return 0;
}
static int hfs_file_fsync(struct file *filp, loff_t start, loff_t end,
int datasync)
{
struct inode *inode = filp->f_mapping->host;
struct super_block * sb;
int ret, err;
ret = file_write_and_wait_range(filp, start, end);
if (ret)
return ret;
inode_lock(inode);
/* sync the inode to buffers */
ret = write_inode_now(inode, 0);
/* sync the superblock to buffers */
sb = inode->i_sb;
flush_delayed_work(&HFS_SB(sb)->mdb_work);
/* .. finally sync the buffers to disk */
err = sync_blockdev(sb->s_bdev);
if (!ret)
ret = err;
inode_unlock(inode);
return ret;
}
static const struct file_operations hfs_file_operations = {
.llseek = generic_file_llseek,
.read_iter = generic_file_read_iter,
.write_iter = generic_file_write_iter,
.mmap_prepare = generic_file_mmap_prepare,
.splice_read = filemap_splice_read,
.fsync = hfs_file_fsync,
.open = hfs_file_open,
.release = hfs_file_release,
};
static const struct inode_operations hfs_file_inode_operations = {
.lookup = hfs_file_lookup,
.setattr = hfs_inode_setattr,
.listxattr = generic_listxattr,
};
View Git Blame Copy Permalink