readdir.c

Linux内核自带的cifs模块

/*
 *   fs/cifs/readdir.c
 *
 *   Directory search handling
 *
 *   Copyright (C) International Business Machines  Corp., 2004, 2007
 *   Author(s): Steve French ([e-mail])
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/stat.h>
#include <linux/smp_lock.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "cifsfs.h"

#ifdef CONFIG_CIFS_DEBUG2
static void dump_cifs_file_struct(struct file *file, char *label)
{
	struct cifsFileInfo *cf;

	if (file) {
		cf = file->private_data;
		if (cf == NULL) {
			cFYI(1, ("empty cifs private file data"));
			return;
		}
		if (cf->invalidHandle) {
			cFYI(1, ("invalid handle"));
		}
		if (cf->srch_inf.endOfSearch) {
			cFYI(1, ("end of search"));
		}
		if (cf->srch_inf.emptyDir) {
			cFYI(1, ("empty dir"));
		}
	}
}
#endif /* DEBUG2 */

/* Returns one if new inode created (which therefore needs to be hashed) */
/* Might check in the future if inode number changed so we can rehash inode */
static int construct_dentry(struct qstr *qstring, struct file *file,
	struct inode **ptmp_inode, struct dentry **pnew_dentry)
{
	struct dentry *tmp_dentry;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	int rc = 0;

	cFYI(1, ("For %s", qstring->name));
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
	cifs_sb = CIFS_SB(file->f_dentry->d_sb);
	pTcon = cifs_sb->tcon;

	qstring->hash = full_name_hash(qstring->name, qstring->len);
	tmp_dentry = d_lookup(file->f_dentry, qstring);
	if (tmp_dentry) {
		cFYI(0, ("existing dentry with inode 0x%p",
			 tmp_dentry->d_inode));
		*ptmp_inode = tmp_dentry->d_inode;
/* BB overwrite old name? i.e. tmp_dentry->d_name and tmp_dentry->d_name.len??*/
		if (*ptmp_inode == NULL) {
			*ptmp_inode = new_inode(file->f_dentry->d_sb);
#else
	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
	pTcon = cifs_sb->tcon;

	qstring->hash = full_name_hash(qstring->name, qstring->len);
	tmp_dentry = d_lookup(file->f_path.dentry, qstring);
	if (tmp_dentry) {
		cFYI(0, ("existing dentry with inode 0x%p",
			 tmp_dentry->d_inode));
		*ptmp_inode = tmp_dentry->d_inode;
/* BB overwrite old name? i.e. tmp_dentry->d_name and tmp_dentry->d_name.len??*/
		if (*ptmp_inode == NULL) {
			*ptmp_inode = new_inode(file->f_path.dentry->d_sb);
#endif
			if (*ptmp_inode == NULL)
				return rc;
			rc = 1;
		}
#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 19)
		if (file->f_path.dentry->d_sb->s_flags & MS_NOATIME)
#else
		if (file->f_dentry->d_sb->s_flags & MS_NOATIME)
#endif
			(*ptmp_inode)->i_flags |= S_NOATIME | S_NOCMTIME;
	} else {
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
		tmp_dentry = d_alloc(file->f_dentry, qstring);
#else
		tmp_dentry = d_alloc(file->f_path.dentry, qstring);
#endif
		if (tmp_dentry == NULL) {
			cERROR(1, ("Failed allocating dentry"));
			*ptmp_inode = NULL;
			return rc;
		}
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20)
		*ptmp_inode = new_inode(file->f_dentry->d_sb);
#else
		*ptmp_inode = new_inode(file->f_path.dentry->d_sb);
#endif
		if (pTcon->nocase)
			tmp_dentry->d_op = &cifs_ci_dentry_ops;
		else
			tmp_dentry->d_op = &cifs_dentry_ops;
		if (*ptmp_inode == NULL)
			return rc;
#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 19)
		if (file->f_path.dentry->d_sb->s_flags & MS_NOATIME)
#else
		if (file->f_dentry->d_sb->s_flags & MS_NOATIME)
#endif
			(*ptmp_inode)->i_flags |= S_NOATIME | S_NOCMTIME;
		rc = 2;
	}

	tmp_dentry->d_time = jiffies;
	*pnew_dentry = tmp_dentry;
	return rc;
}

static void AdjustForTZ(struct cifsTconInfo *tcon, struct inode *inode)
{
	if ((tcon) && (tcon->ses) && (tcon->ses->server)) {
#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0)
		inode->i_ctime.tv_sec += tcon->ses->server->timeAdj;
		inode->i_mtime.tv_sec += tcon->ses->server->timeAdj;
		inode->i_atime.tv_sec += tcon->ses->server->timeAdj;
#else
		inode->i_ctime += tcon->ses->server->timeAdj;
		inode->i_mtime += tcon->ses->server->timeAdj;
		inode->i_atime += tcon->ses->server->timeAdj;
#endif
	}
	return;
}


static void fill_in_inode(struct inode *tmp_inode, int new_buf_type,
			  char *buf, int *pobject_type, int isNewInode)
{
	loff_t local_size;
#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0)
	struct timespec local_mtime;
#else
	time_t local_mtime;
#endif


	struct cifsInodeInfo *cifsInfo = CIFS_I(tmp_inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(tmp_inode->i_sb);
	__u32 attr;
	__u64 allocation_size;
	__u64 end_of_file;

	/* save mtime and size */
	local_mtime = tmp_inode->i_mtime;
	local_size  = tmp_inode->i_size;

	if (new_buf_type) {
		FILE_DIRECTORY_INFO *pfindData = (FILE_DIRECTORY_INFO *)buf;

		attr = le32_to_cpu(pfindData->ExtFileAttributes);
		allocation_size = le64_to_cpu(pfindData->AllocationSize);
		end_of_file = le64_to_cpu(pfindData->EndOfFile);
		tmp_inode->i_atime =
		      cifs_NTtimeToUnix(le64_to_cpu(pfindData->LastAccessTime));
		tmp_inode->i_mtime =
		      cifs_NTtimeToUnix(le64_to_cpu(pfindData->LastWriteTime));
		tmp_inode->i_ctime =
		      cifs_NTtimeToUnix(le64_to_cpu(pfindData->ChangeTime));
	} else { /* legacy, OS2 and DOS style */
/*		struct timespec ts;*/
		FIND_FILE_STANDARD_INFO * pfindData =
			(FIND_FILE_STANDARD_INFO *)buf;

		tmp_inode->i_mtime = cnvrtDosUnixTm(
				le16_to_cpu(pfindData->LastWriteDate),
				le16_to_cpu(pfindData->LastWriteTime));
		tmp_inode->i_atime = cnvrtDosUnixTm(
				le16_to_cpu(pfindData->LastAccessDate),
				le16_to_cpu(pfindData->LastAccessTime));
		tmp_inode->i_ctime = cnvrtDosUnixTm(
				le16_to_cpu(pfindData->LastWriteDate),
				le16_to_cpu(pfindData->LastWriteTime));
		AdjustForTZ(cifs_sb->tcon, tmp_inode);
		attr = le16_to_cpu(pfindData->Attributes);
		allocation_size = le32_to_cpu(pfindData->AllocationSize);
		end_of_file = le32_to_cpu(pfindData->DataSize);
	}

	/* Linux can not store file creation time unfortunately so ignore it */

	cifsInfo->cifsAttrs = attr;
	cifsInfo->time = jiffies;

	/* treat dos attribute of read-only as read-only mode bit e.g. 555? */
	/* 2767 perms - indicate mandatory locking */
		/* BB fill in uid and gid here? with help from winbind?
		   or retrieve from NTFS stream extended attribute */
	if (atomic_read(&cifsInfo->inUse) == 0) {
		tmp_inode->i_uid = cifs_sb->mnt_uid;
		tmp_inode->i_gid = cifs_sb->mnt_gid;
		/* set default mode. will override for dirs below */
		tmp_inode->i_mode = cifs_sb->mnt_file_mode;
	} else {
		/* mask off the type bits since it gets set
		below and we do not want to get two type
		bits set */
		tmp_inode->i_mode &= ~S_IFMT;
	}

	if (attr & ATTR_DIRECTORY) {
		*pobject_type = DT_DIR;
		/* override default perms since we do not lock dirs */
		if (atomic_read(&cifsInfo->inUse) == 0) {
			tmp_inode->i_mode = cifs_sb->mnt_dir_mode;
		}
		tmp_inode->i_mode |= S_IFDIR;
	} else if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) &&
		   (attr & ATTR_SYSTEM)) {
		if (end_of_file == 0)  {
			*pobject_type = DT_FIFO;
			tmp_inode->i_mode |= S_IFIFO;
		} else {
			/* rather than get the type here, we mark the
			inode as needing revalidate and get the real type
			(blk vs chr vs. symlink) later ie in lookup */
			*pobject_type = DT_REG;
			tmp_inode->i_mode |= S_IFREG;
			cifsInfo->time = 0;
		}
/* we no longer mark these because we could not follow them */
/*        } else if (attr & ATTR_REPARSE) {
		*pobject_type = DT_LNK;
		tmp_inode->i_mode |= S_IFLNK; */
	} else {
		*pobject_type = DT_REG;
		tmp_inode->i_mode |= S_IFREG;
		if (attr & ATTR_READONLY)
			tmp_inode->i_mode &= ~(S_IWUGO);
		else if ((tmp_inode->i_mode & S_IWUGO) == 0)
			/* the ATTR_READONLY flag may have been changed on   */
			/* server -- set any w bits allowed by mnt_file_mode */
			tmp_inode->i_mode |= (S_IWUGO & cifs_sb->mnt_file_mode);
	} /* could add code here - to validate if device or weird share type? */

	/* can not fill in nlink here as in qpathinfo version and Unx search */
	if (atomic_read(&cifsInfo->inUse) == 0) {
		atomic_set(&cifsInfo->inUse, 1);
	}

	spin_lock(&tmp_inode->i_lock);
	if (is_size_safe_to_change(cifsInfo, end_of_file)) {
		/* can not safely change the file size here if the
		client is writing to it due to potential races */
		i_size_write(tmp_inode, end_of_file);

	/* 512 bytes (2**9) is the fake blocksize that must be used */
	/* for this calculation, even though the reported blocksize is larger */
		tmp_inode->i_blocks = (512 - 1 + allocation_size) >> 9;
	}
	spin_unlock(&tmp_inode->i_lock);

	if (allocation_size < end_of_file)
		cFYI(1, ("May be sparse file, allocation less than file size"));
	cFYI(1, ("File Size %ld and blocks %llu",
		(unsigned long)tmp_inode->i_size,
		(unsigned long long)tmp_inode->i_blocks));
	if (S_ISREG(tmp_inode->i_mode)) {
		cFYI(1, ("File inode"));
		tmp_inode->i_op = &cifs_file_inode_ops;
		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO) {
			if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
				tmp_inode->i_fop = &cifs_file_direct_nobrl_ops;
			else
				tmp_inode->i_fop = &cifs_file_direct_ops;
		} else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
			tmp_inode->i_fop = &cifs_file_nobrl_ops;
		else
			tmp_inode->i_fop = &cifs_file_ops;

		if ((cifs_sb->tcon) && (cifs_sb->tcon->ses) &&
		   (cifs_sb->tcon->ses->server->maxBuf <
			PAGE_CACHE_SIZE + MAX_CIFS_HDR_SIZE))
			tmp_inode->i_data.a_ops = &cifs_addr_ops_smallbuf;
		else
			tmp_inode->i_data.a_ops = &cifs_addr_ops;

		if (isNewInode)
			return; /* No sense invalidating pages for new inode
				   since have not started caching readahead file
				   data yet */

		if (timespec_equal(&tmp_inode->i_mtime, &local_mtime) &&
			(local_size == tmp_inode->i_size)) {
			cFYI(1, ("inode exists but unchanged"));
		} else {
			/* file may have changed on server */
			cFYI(1, ("invalidate inode, readdir detected change"));
			invalidate_remote_inode(tmp_inode);
		}
	} else if (S_ISDIR(tmp_inode->i_mode)) {
		cFYI(1, ("Directory inode"));
		tmp_inode->i_op = &cifs_dir_inode_ops;
		tmp_inode->i_fop = &cifs_dir_ops;
	} else if (S_ISLNK(tmp_inode->i_mode)) {
		cFYI(1, ("Symbolic Link inode"));
		tmp_inode->i_op = &cifs_symlink_inode_ops;
	} else {
		cFYI(1, ("Init special inode"));
		init_special_inode(tmp_inode, tmp_inode->i_mode,
				   tmp_inode->i_rdev);
	}
}

static void unix_fill_in_inode(struct inode *tmp_inode,
	FILE_UNIX_INFO *pfindData, int *pobject_type, int isNewInode)
{
	loff_t local_size;
#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 5, 0)
	struct timespec local_mtime;
#else
	time_t local_mtime;
#endif

	struct cifsInodeInfo *cifsInfo = CIFS_I(tmp_inode);
	struct cifs_sb_info *cifs_sb = CIFS_SB(tmp_inode->i_sb);

	__u32 type = le32_to_cpu(pfindData->Type);
	__u64 num_of_bytes = le64_to_cpu(pfindData->NumOfBytes);
	__u64 end_of_file = le64_to_cpu(pfindData->EndOfFile);
	cifsInfo->time = jiffies;
	atomic_inc(&cifsInfo->inUse);

	/* save mtime and size */
	local_mtime = tmp_inode->i_mtime;
	local_size  = tmp_inode->i_size;

	tmp_inode->i_atime =
	    cifs_NTtimeToUnix(le64_to_cpu(pfindData->LastAccessTime));
	tmp_inode->i_mtime =
	    cifs_NTtimeToUnix(le64_to_cpu(pfindData->LastModificationTime));
	tmp_inode->i_ctime =
	    cifs_NTtimeToUnix(le64_to_cpu(pfindData->LastStatusChange));

	tmp_inode->i_mode = le64_to_cpu(pfindData->Permissions);
	/* since we set the inode type below we need to mask off type
	   to avoid strange results if bits above were corrupt */
	tmp_inode->i_mode &= ~S_IFMT;
	if (type == UNIX_FILE) {
		*pobject_type = DT_REG;
		tmp_inode->i_mode |= S_IFREG;
	} else if (type == UNIX_SYMLINK) {
		*pobject_type = DT_LNK;
		tmp_inode->i_mode |= S_IFLNK;
	} else if (type == UNIX_DIR) {
		*pobject_type = DT_DIR;
		tmp_inode->i_mode |= S_IFDIR;
	} else if (type == UNIX_CHARDEV) {
		*pobject_type = DT_CHR;
		tmp_inode->i_mode |= S_IFCHR;
		tmp_inode->i_rdev = MKDEV(le64_to_cpu(pfindData->DevMajor),
				le64_to_cpu(pfindData->DevMinor) & MINORMASK);
	} else if (type == UNIX_BLOCKDEV) {
		*pobject_type = DT_BLK;
		tmp_inode->i_mode |= S_IFBLK;
		tmp_inode->i_rdev = MKDEV(le64_to_cpu(pfindData->DevMajor),
				le64_to_cpu(pfindData->DevMinor) & MINORMASK);
	} else if (type == UNIX_FIFO) {
		*pobject_type = DT_FIFO;
		tmp_inode->i_mode |= S_IFIFO;
	} else if (type == UNIX_SOCKET) {
		*pobject_type = DT_SOCK;
		tmp_inode->i_mode |= S_IFSOCK;
	} else {