Signed-off-by: Josef 'Jeff' Sipek <jeffpc@xxxxxxxxxxxxxx>
---
fs/cmsfs/file.c | 204 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 204 insertions(+), 0 deletions(-)
create mode 100644 fs/cmsfs/file.c
diff --git a/fs/cmsfs/file.c b/fs/cmsfs/file.c
new file mode 100644
index 0000000..26f23f8
--- /dev/null
+++ b/fs/cmsfs/file.c
@@ -0,0 +1,204 @@
+/*
+ * CMSFS
+ *
+ * (C) 2008 Josef 'Jeff' Sipek <jeffpc@xxxxxxxxxxxxxx>
+ *
+ * Based on cmsfs from 2.4.12-ac6:
+ *
+ * (C) 2001 Rick Troth <rtroth@xxxxxxx>
+ * (C) 2001 BMC Software, Inc., Houston, Texas, USA
+ *
+ */
+
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/uaccess.h>
+
+#include "cmsfs.h"
+
+/**
+ * __read_recfm_fixed - read len bytes from file position pos
+ * @inode: inode to read from
+ * @buf: user buffer pointer to copy data to
+ * @len: length of the buffer
+ * @pos: position into the inode
+ */
+static ssize_t __read_recfm_fixed(struct inode *inode, char __user *buf,
+ size_t len, loff_t pos)
+{
+ struct cmsfs_inode_info *ci = CMSFS_I(inode);
+ struct super_block *sb = inode->i_sb;
+ struct page *page;
+ unsigned char *kaddr;
+ u32 blkoff;
+ size_t err = -EIO;
+
+ BUG_ON(ci->recfm != RECFM_FIXED);
+ BUG_ON(sb->s_blocksize > PAGE_SIZE);
+
+ page = read_mapping_page(inode->i_mapping, pos >> PAGE_SHIFT, NULL);
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+
+ kaddr = kmap(page);
+ if (PageError(page))
+ goto out;
+
+ blkoff = pos & ~PAGE_MASK;
+
+ /* won't read more than a page */
+ len = min(len, PAGE_SIZE - blkoff);
+
+ err = copy_to_user(buf, kaddr + blkoff, len);
+ if (!err)
+ err = len;
+
+out:
+ kunmap(page);
+ page_cache_release(page);
+ return err;
+}
+
+/**
+ * cmsfs_file_read - read from a file
+ * @file: file to read from
+ * @buf: user buffer pointer for data
+ * @len: length of the buffer
+ * @ppos: pointer to the file offset to read at
+ */
+static ssize_t cmsfs_file_read(struct file *file, char __user *buf, size_t len,
+ loff_t *ppos)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ ssize_t ret;
+
+ if ((*ppos < inode->i_size) && (*ppos + len > inode->i_size))
+ len = inode->i_size - *ppos;
+ else if (*ppos >= inode->i_size)
+ return 0;
+
+ switch (CMSFS_I(inode)->recfm) {
+ case RECFM_FIXED:
+ ret = __read_recfm_fixed(inode, buf, len, *ppos);
+ break;
+ case RECFM_VAR:
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ if (ret > 0)
+ *ppos = *ppos + ret;
+
+ return ret;
+}
+
+/**
+ * cmsfs_readdir - readdir
+ * @file: file to readdir
+ * @dirent: ?
+ * @filldir: readdir filler function ptr
+ */
+static int cmsfs_readdir(struct file *file, void *dirent, filldir_t filldir)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct super_block *sb = inode->i_sb;
+ struct cmsfs_inode_info *cinode = CMSFS_I(inode);
+ struct CMSFSFST *fst;
+ struct page *page;
+ char outname[18];
+ int i;
+ int err = 0;
+
+ if (inode->i_ino != CMSFS_DIRECTOR_INO)
+ return -ENOTDIR;
+
+ /* FIXME: this should go away, I think */
+ if (file->f_pos != 0)
+ return 0;
+
+ page = NULL;
+ fst = NULL;
+ file->f_pos = 0;
+
+ for (i = 0; i < cinode->items; i++, fst++) {
+ if ((i * cinode->lrecl) % CMSFS_SB(sb)->blksz == 0) {
+ if (i) {
+ kunmap(page);
+ page_cache_release(page);
+ }
+
+ page = read_mapping_page(inode->i_mapping,
+ (i * cinode->lrecl) /
+ CMSFS_SB(sb)->blksz,
+ NULL);
+ if (IS_ERR(page)) {
+ err = PTR_ERR(page);
+ goto out;
+ }
+
+ fst = kmap(page);
+ if (PageError(page)) {
+ err = -EIO;
+ goto out_release;
+ }
+ }
+
+ /*
+ * skipping .DIRECTOR and .ALLOCMAP, but using the dirent
+ * space for the '.' and '..' entries
+ */
+ if (i < 2) {
+ err = filldir(dirent, i ? ".." : ".",
+ i ? 2 : 1, file->f_pos,
+ CMSFS_DIRECTOR_INO,
+ DT_DIR);
+ if (err)
+ break;
+ continue;
+ }
+
+ munge_name(fst->FSTFNAME, outname);
+
+ /* No subdirs so all files are regular */
+ err = filldir(dirent, outname, strlen(outname), file->f_pos,
+ i + CMSFS_FIRST_INO, DT_REG);
+ if (err)
+ break;
+
+ /* set the file possition */
+ file->f_pos += cinode->lrecl;
+ }
+
+ kunmap(page);
+out_release:
+ page_cache_release(page);
+out:
+ return err;
+}
+
+/**
+ * cmsfs_file_open - open routine
+ * @inode: inode to read
+ * @file: file ptr to be associated with the inode
+ *
+ * NOTE: The only reason this exists is because it's a good place to prevent
+ * RECFM_VAR files being open, and later read. Once that's supported, this
+ * function should go away.
+ */
+static int cmsfs_file_open(struct inode *inode, struct file *file)
+{
+ if (CMSFS_I(inode)->recfm != RECFM_FIXED) {
+ printk("cmsfs: cannot open files with recfm != fixed\n");
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+struct file_operations cmsfs_file_ops = {
+ .readdir = cmsfs_readdir,
+ .open = cmsfs_file_open,
+ .read = cmsfs_file_read,
+};
--
1.5.6.3
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