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-rw-r--r--fs/fat/file.c308
1 files changed, 308 insertions, 0 deletions
diff --git a/fs/fat/file.c b/fs/fat/file.c
new file mode 100644
index 0000000..62ffa91
--- /dev/null
+++ b/fs/fat/file.c
@@ -0,0 +1,308 @@
+/*
+ * linux/fs/fat/file.c
+ *
+ * Written 1992,1993 by Werner Almesberger
+ *
+ * regular file handling primitives for fat-based filesystems
+ */
+
+#include <linux/module.h>
+#include <linux/time.h>
+#include <linux/msdos_fs.h>
+#include <linux/smp_lock.h>
+#include <linux/buffer_head.h>
+
+static ssize_t fat_file_aio_write(struct kiocb *iocb, const char __user *buf,
+ size_t count, loff_t pos)
+{
+ struct inode *inode = iocb->ki_filp->f_dentry->d_inode;
+ int retval;
+
+ retval = generic_file_aio_write(iocb, buf, count, pos);
+ if (retval > 0) {
+ inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
+ MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
+ mark_inode_dirty(inode);
+// check the locking rules
+// if (IS_SYNC(inode))
+// fat_sync_inode(inode);
+ }
+ return retval;
+}
+
+static ssize_t fat_file_writev(struct file *filp, const struct iovec *iov,
+ unsigned long nr_segs, loff_t *ppos)
+{
+ struct inode *inode = filp->f_dentry->d_inode;
+ int retval;
+
+ retval = generic_file_writev(filp, iov, nr_segs, ppos);
+ if (retval > 0) {
+ inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
+ MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
+ mark_inode_dirty(inode);
+ }
+ return retval;
+}
+
+int fat_generic_ioctl(struct inode *inode, struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+ u32 __user *user_attr = (u32 __user *)arg;
+
+ switch (cmd) {
+ case FAT_IOCTL_GET_ATTRIBUTES:
+ {
+ u32 attr;
+
+ if (inode->i_ino == MSDOS_ROOT_INO)
+ attr = ATTR_DIR;
+ else
+ attr = fat_attr(inode);
+
+ return put_user(attr, user_attr);
+ }
+ case FAT_IOCTL_SET_ATTRIBUTES:
+ {
+ u32 attr, oldattr;
+ int err, is_dir = S_ISDIR(inode->i_mode);
+ struct iattr ia;
+
+ err = get_user(attr, user_attr);
+ if (err)
+ return err;
+
+ down(&inode->i_sem);
+
+ if (IS_RDONLY(inode)) {
+ err = -EROFS;
+ goto up;
+ }
+
+ /*
+ * ATTR_VOLUME and ATTR_DIR cannot be changed; this also
+ * prevents the user from turning us into a VFAT
+ * longname entry. Also, we obviously can't set
+ * any of the NTFS attributes in the high 24 bits.
+ */
+ attr &= 0xff & ~(ATTR_VOLUME | ATTR_DIR);
+ /* Merge in ATTR_VOLUME and ATTR_DIR */
+ attr |= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) |
+ (is_dir ? ATTR_DIR : 0);
+ oldattr = fat_attr(inode);
+
+ /* Equivalent to a chmod() */
+ ia.ia_valid = ATTR_MODE | ATTR_CTIME;
+ if (is_dir) {
+ ia.ia_mode = MSDOS_MKMODE(attr,
+ S_IRWXUGO & ~sbi->options.fs_dmask)
+ | S_IFDIR;
+ } else {
+ ia.ia_mode = MSDOS_MKMODE(attr,
+ (S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO))
+ & ~sbi->options.fs_fmask)
+ | S_IFREG;
+ }
+
+ /* The root directory has no attributes */
+ if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
+ err = -EINVAL;
+ goto up;
+ }
+
+ if (sbi->options.sys_immutable) {
+ if ((attr | oldattr) & ATTR_SYS) {
+ if (!capable(CAP_LINUX_IMMUTABLE)) {
+ err = -EPERM;
+ goto up;
+ }
+ }
+ }
+
+ /* This MUST be done before doing anything irreversible... */
+ err = notify_change(filp->f_dentry, &ia);
+ if (err)
+ goto up;
+
+ if (sbi->options.sys_immutable) {
+ if (attr & ATTR_SYS)
+ inode->i_flags |= S_IMMUTABLE;
+ else
+ inode->i_flags &= S_IMMUTABLE;
+ }
+
+ MSDOS_I(inode)->i_attrs = attr & ATTR_UNUSED;
+ mark_inode_dirty(inode);
+ up:
+ up(&inode->i_sem);
+ return err;
+ }
+ default:
+ return -ENOTTY; /* Inappropriate ioctl for device */
+ }
+}
+
+struct file_operations fat_file_operations = {
+ .llseek = generic_file_llseek,
+ .read = do_sync_read,
+ .write = do_sync_write,
+ .readv = generic_file_readv,
+ .writev = fat_file_writev,
+ .aio_read = generic_file_aio_read,
+ .aio_write = fat_file_aio_write,
+ .mmap = generic_file_mmap,
+ .ioctl = fat_generic_ioctl,
+ .fsync = file_fsync,
+ .sendfile = generic_file_sendfile,
+};
+
+int fat_notify_change(struct dentry *dentry, struct iattr *attr)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
+ struct inode *inode = dentry->d_inode;
+ int mask, error = 0;
+
+ lock_kernel();
+
+ /* FAT cannot truncate to a longer file */
+ if (attr->ia_valid & ATTR_SIZE) {
+ if (attr->ia_size > inode->i_size) {
+ error = -EPERM;
+ goto out;
+ }
+ }
+
+ error = inode_change_ok(inode, attr);
+ if (error) {
+ if (sbi->options.quiet)
+ error = 0;
+ goto out;
+ }
+ if (((attr->ia_valid & ATTR_UID) &&
+ (attr->ia_uid != sbi->options.fs_uid)) ||
+ ((attr->ia_valid & ATTR_GID) &&
+ (attr->ia_gid != sbi->options.fs_gid)) ||
+ ((attr->ia_valid & ATTR_MODE) &&
+ (attr->ia_mode & ~MSDOS_VALID_MODE)))
+ error = -EPERM;
+
+ if (error) {
+ if (sbi->options.quiet)
+ error = 0;
+ goto out;
+ }
+ error = inode_setattr(inode, attr);
+ if (error)
+ goto out;
+
+ if (S_ISDIR(inode->i_mode))
+ mask = sbi->options.fs_dmask;
+ else
+ mask = sbi->options.fs_fmask;
+ inode->i_mode &= S_IFMT | (S_IRWXUGO & ~mask);
+out:
+ unlock_kernel();
+ return error;
+}
+
+EXPORT_SYMBOL(fat_notify_change);
+
+/* Free all clusters after the skip'th cluster. */
+static int fat_free(struct inode *inode, int skip)
+{
+ struct super_block *sb = inode->i_sb;
+ int err, wait, free_start, i_start, i_logstart;
+
+ if (MSDOS_I(inode)->i_start == 0)
+ return 0;
+
+ /*
+ * Write a new EOF, and get the remaining cluster chain for freeing.
+ */
+ wait = IS_DIRSYNC(inode);
+ if (skip) {
+ struct fat_entry fatent;
+ int ret, fclus, dclus;
+
+ ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
+ if (ret < 0)
+ return ret;
+ else if (ret == FAT_ENT_EOF)
+ return 0;
+
+ fatent_init(&fatent);
+ ret = fat_ent_read(inode, &fatent, dclus);
+ if (ret == FAT_ENT_EOF) {
+ fatent_brelse(&fatent);
+ return 0;
+ } else if (ret == FAT_ENT_FREE) {
+ fat_fs_panic(sb,
+ "%s: invalid cluster chain (i_pos %lld)",
+ __FUNCTION__, MSDOS_I(inode)->i_pos);
+ ret = -EIO;
+ } else if (ret > 0) {
+ err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
+ if (err)
+ ret = err;
+ }
+ fatent_brelse(&fatent);
+ if (ret < 0)
+ return ret;
+
+ free_start = ret;
+ i_start = i_logstart = 0;
+ fat_cache_inval_inode(inode);
+ } else {
+ fat_cache_inval_inode(inode);
+
+ i_start = free_start = MSDOS_I(inode)->i_start;
+ i_logstart = MSDOS_I(inode)->i_logstart;
+ MSDOS_I(inode)->i_start = 0;
+ MSDOS_I(inode)->i_logstart = 0;
+ }
+ MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
+ inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
+ if (wait) {
+ err = fat_sync_inode(inode);
+ if (err)
+ goto error;
+ } else
+ mark_inode_dirty(inode);
+ inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
+
+ /* Freeing the remained cluster chain */
+ return fat_free_clusters(inode, free_start);
+
+error:
+ if (i_start) {
+ MSDOS_I(inode)->i_start = i_start;
+ MSDOS_I(inode)->i_logstart = i_logstart;
+ }
+ return err;
+}
+
+void fat_truncate(struct inode *inode)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+ const unsigned int cluster_size = sbi->cluster_size;
+ int nr_clusters;
+
+ /*
+ * This protects against truncating a file bigger than it was then
+ * trying to write into the hole.
+ */
+ if (MSDOS_I(inode)->mmu_private > inode->i_size)
+ MSDOS_I(inode)->mmu_private = inode->i_size;
+
+ nr_clusters = (inode->i_size + (cluster_size - 1)) >> sbi->cluster_bits;
+
+ lock_kernel();
+ fat_free(inode, nr_clusters);
+ unlock_kernel();
+}
+
+struct inode_operations fat_file_inode_operations = {
+ .truncate = fat_truncate,
+ .setattr = fat_notify_change,
+};
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