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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /fs/hfs/inode.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/hfs/inode.c')
-rw-r--r--fs/hfs/inode.c706
1 files changed, 706 insertions, 0 deletions
diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
new file mode 100644
index 0000000000..ee349b72cf
--- /dev/null
+++ b/fs/hfs/inode.c
@@ -0,0 +1,706 @@
+/*
+ * 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_writepage(struct page *page, struct writeback_control *wbc)
+{
+ return block_write_full_page(page, hfs_get_block, wbc);
+}
+
+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(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, struct page **pagep, void **fsdata)
+{
+ int ret;
+
+ *pagep = NULL;
+ ret = cont_write_begin(file, mapping, pos, len, pagep, 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,
+ .writepage = hfs_writepage,
+ .write_begin = hfs_write_begin,
+ .write_end = generic_write_end,
+ .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);
+ inode->i_mtime = inode->i_atime = inode_set_ctime_current(inode);
+ HFS_I(inode)->flags = 0;
+ HFS_I(inode)->rsrc_inode = NULL;
+ HFS_I(inode)->fs_blocks = 0;
+ 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;
+
+ 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->i_atime = inode->i_mtime = 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->i_atime = inode->i_mtime = 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->i_mtime);
+ 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->i_mtime);
+
+ 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);
+ inode->i_atime = inode->i_mtime = inode_set_ctime_current(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 = generic_file_mmap,
+ .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,
+};