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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163// SPDX-License-Identifier: GPL-2.0-only/* * dir.c * * PURPOSE * Directory handling routines for the OSTA-UDF(tm) filesystem. * * COPYRIGHT * (C) 1998-2004 Ben Fennema * * HISTORY * * 10/05/98 dgb Split directory operations into its own file * Implemented directory reads via do_udf_readdir * 10/06/98 Made directory operations work! * 11/17/98 Rewrote directory to support ICBTAG_FLAG_AD_LONG * 11/25/98 blf Rewrote directory handling (readdir+lookup) to support reading * across blocks. * 12/12/98 Split out the lookup code to namei.c. bulk of directory * code now in directory.c:udf_fileident_read. */
#include "udfdecl.h"
#include <linux/string.h>#include <linux/errno.h>#include <linux/filelock.h>#include <linux/mm.h>#include <linux/slab.h>#include <linux/bio.h>#include <linux/iversion.h>
#include "udf_i.h"#include "udf_sb.h"
static int udf_readdir(struct file *file, struct dir_context *ctx){ struct inode *dir = file_inode(file); loff_t nf_pos, emit_pos = 0; int flen; unsigned char *fname = NULL; int ret = 0; struct super_block *sb = dir->i_sb; bool pos_valid = false; struct udf_fileident_iter iter;
if (ctx->pos == 0) { if (!dir_emit_dot(file, ctx)) return 0; ctx->pos = 1; } nf_pos = (ctx->pos - 1) << 2; if (nf_pos >= dir->i_size) goto out;
/* * Something changed since last readdir (either lseek was called or dir * changed)? We need to verify the position correctly points at the * beginning of some dir entry so that the directory parsing code does * not get confused. Since UDF does not have any reliable way of * identifying beginning of dir entry (names are under user control), * we need to scan the directory from the beginning. */ if (!inode_eq_iversion(dir, *(u64 *)file->private_data)) { emit_pos = nf_pos; nf_pos = 0; } else { pos_valid = true; }
fname = kmalloc(UDF_NAME_LEN, GFP_KERNEL); if (!fname) { ret = -ENOMEM; goto out; }
for (ret = udf_fiiter_init(&iter, dir, nf_pos); !ret && iter.pos < dir->i_size; ret = udf_fiiter_advance(&iter)) { struct kernel_lb_addr tloc; udf_pblk_t iblock;
/* Still not at offset where user asked us to read from? */ if (iter.pos < emit_pos) continue;
/* Update file position only if we got past the current one */ pos_valid = true; ctx->pos = (iter.pos >> 2) + 1;
if (iter.fi.fileCharacteristics & FID_FILE_CHAR_DELETED) { if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNDELETE)) continue; }
if (iter.fi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) { if (!UDF_QUERY_FLAG(sb, UDF_FLAG_UNHIDE)) continue; }
if (iter.fi.fileCharacteristics & FID_FILE_CHAR_PARENT) { if (!dir_emit_dotdot(file, ctx)) goto out_iter; continue; }
flen = udf_get_filename(sb, iter.name, iter.fi.lengthFileIdent, fname, UDF_NAME_LEN); if (flen < 0) continue;
tloc = lelb_to_cpu(iter.fi.icb.extLocation); iblock = udf_get_lb_pblock(sb, &tloc, 0); if (!dir_emit(ctx, fname, flen, iblock, DT_UNKNOWN)) goto out_iter; }
if (!ret) { ctx->pos = (iter.pos >> 2) + 1; pos_valid = true; }out_iter: udf_fiiter_release(&iter);out: if (pos_valid) *(u64 *)file->private_data = inode_query_iversion(dir); kfree(fname);
return ret;}
static int udf_dir_open(struct inode *inode, struct file *file){ file->private_data = kzalloc(sizeof(u64), GFP_KERNEL); if (!file->private_data) return -ENOMEM; return 0;}
static int udf_dir_release(struct inode *inode, struct file *file){ kfree(file->private_data); return 0;}
static loff_t udf_dir_llseek(struct file *file, loff_t offset, int whence){ return generic_llseek_cookie(file, offset, whence, (u64 *)file->private_data);}
/* readdir and lookup functions */const struct file_operations udf_dir_operations = { .open = udf_dir_open, .release = udf_dir_release, .llseek = udf_dir_llseek, .read = generic_read_dir, .iterate_shared = udf_readdir, .unlocked_ioctl = udf_ioctl, .fsync = udf_fsync, .setlease = generic_setlease,};