diff options
Diffstat (limited to 'fs/smb/client/readdir.c')
| -rw-r--r-- | fs/smb/client/readdir.c | 1237 |
1 files changed, 1237 insertions, 0 deletions
diff --git a/fs/smb/client/readdir.c b/fs/smb/client/readdir.c new file mode 100644 index 000000000..2d75ba5aa --- /dev/null +++ b/fs/smb/client/readdir.c @@ -0,0 +1,1237 @@ +// SPDX-License-Identifier: LGPL-2.1 +/* + * + * Directory search handling + * + * Copyright (C) International Business Machines Corp., 2004, 2008 + * Copyright (C) Red Hat, Inc., 2011 + * Author(s): Steve French (sfrench@us.ibm.com) + * + */ +#include <linux/fs.h> +#include <linux/pagemap.h> +#include <linux/slab.h> +#include <linux/stat.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" +#include "smb2proto.h" +#include "fs_context.h" +#include "cached_dir.h" + +/* + * To be safe - for UCS to UTF-8 with strings loaded with the rare long + * characters alloc more to account for such multibyte target UTF-8 + * characters. + */ +#define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2) + +#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) { + cifs_dbg(FYI, "empty cifs private file data\n"); + return; + } + if (cf->invalidHandle) + cifs_dbg(FYI, "Invalid handle\n"); + if (cf->srch_inf.endOfSearch) + cifs_dbg(FYI, "end of search\n"); + if (cf->srch_inf.emptyDir) + cifs_dbg(FYI, "empty dir\n"); + } +} +#else +static inline void dump_cifs_file_struct(struct file *file, char *label) +{ +} +#endif /* DEBUG2 */ + +/* + * Attempt to preload the dcache with the results from the FIND_FIRST/NEXT + * + * Find the dentry that matches "name". If there isn't one, create one. If it's + * a negative dentry or the uniqueid or filetype(mode) changed, + * then drop it and recreate it. + */ +static void +cifs_prime_dcache(struct dentry *parent, struct qstr *name, + struct cifs_fattr *fattr) +{ + struct dentry *dentry, *alias; + struct inode *inode; + struct super_block *sb = parent->d_sb; + struct cifs_sb_info *cifs_sb = CIFS_SB(sb); + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + + cifs_dbg(FYI, "%s: for %s\n", __func__, name->name); + + dentry = d_hash_and_lookup(parent, name); + if (!dentry) { + /* + * If we know that the inode will need to be revalidated + * immediately, then don't create a new dentry for it. + * We'll end up doing an on the wire call either way and + * this spares us an invalidation. + */ + if (fattr->cf_flags & CIFS_FATTR_NEED_REVAL) + return; +retry: + dentry = d_alloc_parallel(parent, name, &wq); + } + if (IS_ERR(dentry)) + return; + if (!d_in_lookup(dentry)) { + inode = d_inode(dentry); + if (inode) { + if (d_mountpoint(dentry)) { + dput(dentry); + return; + } + /* + * If we're generating inode numbers, then we don't + * want to clobber the existing one with the one that + * the readdir code created. + */ + if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) + fattr->cf_uniqueid = CIFS_I(inode)->uniqueid; + + /* update inode in place + * if both i_ino and i_mode didn't change */ + if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid && + cifs_fattr_to_inode(inode, fattr) == 0) { + dput(dentry); + return; + } + } + d_invalidate(dentry); + dput(dentry); + goto retry; + } else { + inode = cifs_iget(sb, fattr); + if (!inode) + inode = ERR_PTR(-ENOMEM); + alias = d_splice_alias(inode, dentry); + d_lookup_done(dentry); + if (alias && !IS_ERR(alias)) + dput(alias); + } + dput(dentry); +} + +static bool reparse_file_needs_reval(const struct cifs_fattr *fattr) +{ + if (!(fattr->cf_cifsattrs & ATTR_REPARSE)) + return false; + /* + * The DFS tags should be only intepreted by server side as per + * MS-FSCC 2.1.2.1, but let's include them anyway. + * + * Besides, if cf_cifstag is unset (0), then we still need it to be + * revalidated to know exactly what reparse point it is. + */ + switch (fattr->cf_cifstag) { + case IO_REPARSE_TAG_DFS: + case IO_REPARSE_TAG_DFSR: + case IO_REPARSE_TAG_SYMLINK: + case IO_REPARSE_TAG_NFS: + case 0: + return true; + } + return false; +} + +static void +cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb) +{ + fattr->cf_uid = cifs_sb->ctx->linux_uid; + fattr->cf_gid = cifs_sb->ctx->linux_gid; + + /* + * The IO_REPARSE_TAG_LX_ tags originally were used by WSL but they + * are preferred by the Linux client in some cases since, unlike + * the NFS reparse tag (or EAs), they don't require an extra query + * to determine which type of special file they represent. + * TODO: go through all documented reparse tags to see if we can + * reasonably map some of them to directories vs. files vs. symlinks + */ + if (fattr->cf_cifsattrs & ATTR_DIRECTORY) { + fattr->cf_mode = S_IFDIR | cifs_sb->ctx->dir_mode; + fattr->cf_dtype = DT_DIR; + } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_SYMLINK) { + fattr->cf_mode |= S_IFLNK | cifs_sb->ctx->file_mode; + fattr->cf_dtype = DT_LNK; + } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_FIFO) { + fattr->cf_mode |= S_IFIFO | cifs_sb->ctx->file_mode; + fattr->cf_dtype = DT_FIFO; + } else if (fattr->cf_cifstag == IO_REPARSE_TAG_AF_UNIX) { + fattr->cf_mode |= S_IFSOCK | cifs_sb->ctx->file_mode; + fattr->cf_dtype = DT_SOCK; + } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_CHR) { + fattr->cf_mode |= S_IFCHR | cifs_sb->ctx->file_mode; + fattr->cf_dtype = DT_CHR; + } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_BLK) { + fattr->cf_mode |= S_IFBLK | cifs_sb->ctx->file_mode; + fattr->cf_dtype = DT_BLK; + } else { /* TODO: should we mark some other reparse points (like DFSR) as directories? */ + fattr->cf_mode = S_IFREG | cifs_sb->ctx->file_mode; + fattr->cf_dtype = DT_REG; + } + + /* + * We need to revalidate it further to make a decision about whether it + * is a symbolic link, DFS referral or a reparse point with a direct + * access like junctions, deduplicated files, NFS symlinks. + */ + if (reparse_file_needs_reval(fattr)) + fattr->cf_flags |= CIFS_FATTR_NEED_REVAL; + + /* non-unix readdir doesn't provide nlink */ + fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK; + + if (fattr->cf_cifsattrs & ATTR_READONLY) + fattr->cf_mode &= ~S_IWUGO; + + /* + * We of course don't get ACL info in FIND_FIRST/NEXT results, so + * mark it for revalidation so that "ls -l" will look right. It might + * be super-slow, but if we don't do this then the ownership of files + * may look wrong since the inodes may not have timed out by the time + * "ls" does a stat() call on them. + */ + if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) || + (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID)) + fattr->cf_flags |= CIFS_FATTR_NEED_REVAL; + + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL && + fattr->cf_cifsattrs & ATTR_SYSTEM) { + if (fattr->cf_eof == 0) { + fattr->cf_mode &= ~S_IFMT; + fattr->cf_mode |= S_IFIFO; + fattr->cf_dtype = DT_FIFO; + } else { + /* + * trying to get the type and mode via SFU can be slow, + * so just call those regular files for now, and mark + * for reval + */ + fattr->cf_flags |= CIFS_FATTR_NEED_REVAL; + } + } +} + +/* Fill a cifs_fattr struct with info from SMB_FIND_FILE_POSIX_INFO. */ +static void +cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info, + struct cifs_sb_info *cifs_sb) +{ + struct smb2_posix_info_parsed parsed; + + posix_info_parse(info, NULL, &parsed); + + memset(fattr, 0, sizeof(*fattr)); + fattr->cf_uniqueid = le64_to_cpu(info->Inode); + fattr->cf_bytes = le64_to_cpu(info->AllocationSize); + fattr->cf_eof = le64_to_cpu(info->EndOfFile); + + fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime); + fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime); + fattr->cf_ctime = cifs_NTtimeToUnix(info->CreationTime); + + fattr->cf_nlink = le32_to_cpu(info->HardLinks); + fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes); + + /* + * Since we set the inode type below we need to mask off + * to avoid strange results if bits set above. + * XXX: why not make server&client use the type bits? + */ + fattr->cf_mode = le32_to_cpu(info->Mode) & ~S_IFMT; + + cifs_dbg(FYI, "posix fattr: dev %d, reparse %d, mode %o\n", + le32_to_cpu(info->DeviceId), + le32_to_cpu(info->ReparseTag), + le32_to_cpu(info->Mode)); + + if (fattr->cf_cifsattrs & ATTR_DIRECTORY) { + fattr->cf_mode |= S_IFDIR; + fattr->cf_dtype = DT_DIR; + } else { + /* + * mark anything that is not a dir as regular + * file. special files should have the REPARSE + * attribute and will be marked as needing revaluation + */ + fattr->cf_mode |= S_IFREG; + fattr->cf_dtype = DT_REG; + } + + if (reparse_file_needs_reval(fattr)) + fattr->cf_flags |= CIFS_FATTR_NEED_REVAL; + + sid_to_id(cifs_sb, &parsed.owner, fattr, SIDOWNER); + sid_to_id(cifs_sb, &parsed.group, fattr, SIDGROUP); +} + +static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info) +{ + const FILE_DIRECTORY_INFO *fi = info; + + memset(fattr, 0, sizeof(*fattr)); + fattr->cf_cifsattrs = le32_to_cpu(fi->ExtFileAttributes); + fattr->cf_eof = le64_to_cpu(fi->EndOfFile); + fattr->cf_bytes = le64_to_cpu(fi->AllocationSize); + fattr->cf_createtime = le64_to_cpu(fi->CreationTime); + fattr->cf_atime = cifs_NTtimeToUnix(fi->LastAccessTime); + fattr->cf_ctime = cifs_NTtimeToUnix(fi->ChangeTime); + fattr->cf_mtime = cifs_NTtimeToUnix(fi->LastWriteTime); +} + +void +cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info, + struct cifs_sb_info *cifs_sb) +{ + __dir_info_to_fattr(fattr, info); + cifs_fill_common_info(fattr, cifs_sb); +} + +static void cifs_fulldir_info_to_fattr(struct cifs_fattr *fattr, + SEARCH_ID_FULL_DIR_INFO *info, + struct cifs_sb_info *cifs_sb) +{ + __dir_info_to_fattr(fattr, info); + + /* See MS-FSCC 2.4.19 FileIdFullDirectoryInformation */ + if (fattr->cf_cifsattrs & ATTR_REPARSE) + fattr->cf_cifstag = le32_to_cpu(info->EaSize); + cifs_fill_common_info(fattr, cifs_sb); +} + +static void +cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info, + struct cifs_sb_info *cifs_sb) +{ + int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj; + + memset(fattr, 0, sizeof(*fattr)); + fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate, + info->LastAccessTime, offset); + fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate, + info->LastWriteTime, offset); + fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate, + info->LastWriteTime, offset); + + fattr->cf_cifsattrs = le16_to_cpu(info->Attributes); + fattr->cf_bytes = le32_to_cpu(info->AllocationSize); + fattr->cf_eof = le32_to_cpu(info->DataSize); + + cifs_fill_common_info(fattr, cifs_sb); +} + +/* BB eventually need to add the following helper function to + resolve NT_STATUS_STOPPED_ON_SYMLINK return code when + we try to do FindFirst on (NTFS) directory symlinks */ +/* +int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb, + unsigned int xid) +{ + __u16 fid; + int len; + int oplock = 0; + int rc; + struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb); + char *tmpbuffer; + + rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ, + OPEN_REPARSE_POINT, &fid, &oplock, NULL, + cifs_sb->local_nls, + cifs_remap(cifs_sb); + if (!rc) { + tmpbuffer = kmalloc(maxpath); + rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path, + tmpbuffer, + maxpath -1, + fid, + cifs_sb->local_nls); + if (CIFSSMBClose(xid, ptcon, fid)) { + cifs_dbg(FYI, "Error closing temporary reparsepoint open\n"); + } + } +} + */ + +static int +_initiate_cifs_search(const unsigned int xid, struct file *file, + const char *full_path) +{ + __u16 search_flags; + int rc = 0; + struct cifsFileInfo *cifsFile; + struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file); + struct tcon_link *tlink = NULL; + struct cifs_tcon *tcon; + struct TCP_Server_Info *server; + + if (file->private_data == NULL) { + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) + return PTR_ERR(tlink); + + cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL); + if (cifsFile == NULL) { + rc = -ENOMEM; + goto error_exit; + } + spin_lock_init(&cifsFile->file_info_lock); + file->private_data = cifsFile; + cifsFile->tlink = cifs_get_tlink(tlink); + tcon = tlink_tcon(tlink); + } else { + cifsFile = file->private_data; + tcon = tlink_tcon(cifsFile->tlink); + } + + server = tcon->ses->server; + + if (!server->ops->query_dir_first) { + rc = -ENOSYS; + goto error_exit; + } + + cifsFile->invalidHandle = true; + cifsFile->srch_inf.endOfSearch = false; + + cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos); + +ffirst_retry: + /* test for Unix extensions */ + /* but now check for them on the share/mount not on the SMB session */ + /* if (cap_unix(tcon->ses) { */ + if (tcon->unix_ext) + cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX; + else if (tcon->posix_extensions) + cifsFile->srch_inf.info_level = SMB_FIND_FILE_POSIX_INFO; + else if ((tcon->ses->capabilities & + tcon->ses->server->vals->cap_nt_find) == 0) { + cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD; + } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) { + cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO; + } else /* not srvinos - BB fixme add check for backlevel? */ { + cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO; + } + + search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME; + if (backup_cred(cifs_sb)) + search_flags |= CIFS_SEARCH_BACKUP_SEARCH; + + rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb, + &cifsFile->fid, search_flags, + &cifsFile->srch_inf); + + if (rc == 0) + cifsFile->invalidHandle = false; + /* BB add following call to handle readdir on new NTFS symlink errors + else if STATUS_STOPPED_ON_SYMLINK + call get_symlink_reparse_path and retry with new path */ + else if ((rc == -EOPNOTSUPP) && + (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) { + cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM; + goto ffirst_retry; + } +error_exit: + cifs_put_tlink(tlink); + return rc; +} + +static int +initiate_cifs_search(const unsigned int xid, struct file *file, + const char *full_path) +{ + int rc, retry_count = 0; + + do { + rc = _initiate_cifs_search(xid, file, full_path); + /* + * If we don't have enough credits to start reading the + * directory just try again after short wait. + */ + if (rc != -EDEADLK) + break; + + usleep_range(512, 2048); + } while (retry_count++ < 5); + + return rc; +} + +/* return length of unicode string in bytes */ +static int cifs_unicode_bytelen(const char *str) +{ + int len; + const __le16 *ustr = (const __le16 *)str; + + for (len = 0; len <= PATH_MAX; len++) { + if (ustr[len] == 0) + return len << 1; + } + cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n"); + return len << 1; +} + +static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level) +{ + char *new_entry; + FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry; + + if (level == SMB_FIND_FILE_INFO_STANDARD) { + FIND_FILE_STANDARD_INFO *pfData; + pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo; + + new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) + + pfData->FileNameLength; + } else { + u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset); + + if (old_entry + next_offset < old_entry) { + cifs_dbg(VFS, "Invalid offset %u\n", next_offset); + return NULL; + } + new_entry = old_entry + next_offset; + } + cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry); + /* validate that new_entry is not past end of SMB */ + if (new_entry >= end_of_smb) { + cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n", + new_entry, end_of_smb, old_entry); + return NULL; + } else if (((level == SMB_FIND_FILE_INFO_STANDARD) && + (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb)) + || ((level != SMB_FIND_FILE_INFO_STANDARD) && + (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb))) { + cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n", + new_entry, end_of_smb); + return NULL; + } else + return new_entry; + +} + +struct cifs_dirent { + const char *name; + size_t namelen; + u32 resume_key; + u64 ino; +}; + +static void cifs_fill_dirent_posix(struct cifs_dirent *de, + const struct smb2_posix_info *info) +{ + struct smb2_posix_info_parsed parsed; + + /* payload should have already been checked at this point */ + if (posix_info_parse(info, NULL, &parsed) < 0) { + cifs_dbg(VFS, "Invalid POSIX info payload\n"); + return; + } + + de->name = parsed.name; + de->namelen = parsed.name_len; + de->resume_key = info->Ignored; + de->ino = le64_to_cpu(info->Inode); +} + +static void cifs_fill_dirent_unix(struct cifs_dirent *de, + const FILE_UNIX_INFO *info, bool is_unicode) +{ + de->name = &info->FileName[0]; + if (is_unicode) + de->namelen = cifs_unicode_bytelen(de->name); + else + de->namelen = strnlen(de->name, PATH_MAX); + de->resume_key = info->ResumeKey; + de->ino = le64_to_cpu(info->basic.UniqueId); +} + +static void cifs_fill_dirent_dir(struct cifs_dirent *de, + const FILE_DIRECTORY_INFO *info) +{ + de->name = &info->FileName[0]; + de->namelen = le32_to_cpu(info->FileNameLength); + de->resume_key = info->FileIndex; +} + +static void cifs_fill_dirent_full(struct cifs_dirent *de, + const FILE_FULL_DIRECTORY_INFO *info) +{ + de->name = &info->FileName[0]; + de->namelen = le32_to_cpu(info->FileNameLength); + de->resume_key = info->FileIndex; +} + +static void cifs_fill_dirent_search(struct cifs_dirent *de, + const SEARCH_ID_FULL_DIR_INFO *info) +{ + de->name = &info->FileName[0]; + de->namelen = le32_to_cpu(info->FileNameLength); + de->resume_key = info->FileIndex; + de->ino = le64_to_cpu(info->UniqueId); +} + +static void cifs_fill_dirent_both(struct cifs_dirent *de, + const FILE_BOTH_DIRECTORY_INFO *info) +{ + de->name = &info->FileName[0]; + de->namelen = le32_to_cpu(info->FileNameLength); + de->resume_key = info->FileIndex; +} + +static void cifs_fill_dirent_std(struct cifs_dirent *de, + const FIND_FILE_STANDARD_INFO *info) +{ + de->name = &info->FileName[0]; + /* one byte length, no endianess conversion */ + de->namelen = info->FileNameLength; + de->resume_key = info->ResumeKey; +} + +static int cifs_fill_dirent(struct cifs_dirent *de, const void *info, + u16 level, bool is_unicode) +{ + memset(de, 0, sizeof(*de)); + + switch (level) { + case SMB_FIND_FILE_POSIX_INFO: + cifs_fill_dirent_posix(de, info); + break; + case SMB_FIND_FILE_UNIX: + cifs_fill_dirent_unix(de, info, is_unicode); + break; + case SMB_FIND_FILE_DIRECTORY_INFO: + cifs_fill_dirent_dir(de, info); + break; + case SMB_FIND_FILE_FULL_DIRECTORY_INFO: + cifs_fill_dirent_full(de, info); + break; + case SMB_FIND_FILE_ID_FULL_DIR_INFO: + cifs_fill_dirent_search(de, info); + break; + case SMB_FIND_FILE_BOTH_DIRECTORY_INFO: + cifs_fill_dirent_both(de, info); + break; + case SMB_FIND_FILE_INFO_STANDARD: + cifs_fill_dirent_std(de, info); + break; + default: + cifs_dbg(FYI, "Unknown findfirst level %d\n", level); + return -EINVAL; + } + + return 0; +} + +#define UNICODE_DOT cpu_to_le16(0x2e) + +/* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */ +static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode) +{ + int rc = 0; + + if (!de->name) + return 0; + + if (is_unicode) { + __le16 *ufilename = (__le16 *)de->name; + if (de->namelen == 2) { + /* check for . */ + if (ufilename[0] == UNICODE_DOT) + rc = 1; + } else if (de->namelen == 4) { + /* check for .. */ + if (ufilename[0] == UNICODE_DOT && + ufilename[1] == UNICODE_DOT) + rc = 2; + } + } else /* ASCII */ { + if (de->namelen == 1) { + if (de->name[0] == '.') + rc = 1; + } else if (de->namelen == 2) { + if (de->name[0] == '.' && de->name[1] == '.') + rc = 2; + } + } + + return rc; +} + +/* Check if directory that we are searching has changed so we can decide + whether we can use the cached search results from the previous search */ +static int is_dir_changed(struct file *file) +{ + struct inode *inode = file_inode(file); + struct cifsInodeInfo *cifsInfo = CIFS_I(inode); + + if (cifsInfo->time == 0) + return 1; /* directory was changed, perhaps due to unlink */ + else + return 0; + +} + +static int cifs_save_resume_key(const char *current_entry, + struct cifsFileInfo *file_info) +{ + struct cifs_dirent de; + int rc; + + rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level, + file_info->srch_inf.unicode); + if (!rc) { + file_info->srch_inf.presume_name = de.name; + file_info->srch_inf.resume_name_len = de.namelen; + file_info->srch_inf.resume_key = de.resume_key; + } + return rc; +} + +/* + * Find the corresponding entry in the search. Note that the SMB server returns + * search entries for . and .. which complicates logic here if we choose to + * parse for them and we do not assume that they are located in the findfirst + * return buffer. We start counting in the buffer with entry 2 and increment for + * every entry (do not increment for . or .. entry). + */ +static int +find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos, + struct file *file, const char *full_path, + char **current_entry, int *num_to_ret) +{ + __u16 search_flags; + int rc = 0; + int pos_in_buf = 0; + loff_t first_entry_in_buffer; + loff_t index_to_find = pos; + struct cifsFileInfo *cfile = file->private_data; + struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file); + struct TCP_Server_Info *server = tcon->ses->server; + /* check if index in the buffer */ + + if (!server->ops->query_dir_first || !server->ops->query_dir_next) + return -ENOSYS; + + if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL)) + return -ENOENT; + + *current_entry = NULL; + first_entry_in_buffer = cfile->srch_inf.index_of_last_entry - + cfile->srch_inf.entries_in_buffer; + + /* + * If first entry in buf is zero then is first buffer + * in search response data which means it is likely . and .. + * will be in this buffer, although some servers do not return + * . and .. for the root of a drive and for those we need + * to start two entries earlier. + */ + + dump_cifs_file_struct(file, "In fce "); + if (((index_to_find < cfile->srch_inf.index_of_last_entry) && + is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) { + /* close and restart search */ + cifs_dbg(FYI, "search backing up - close and restart search\n"); + spin_lock(&cfile->file_info_lock); + if (server->ops->dir_needs_close(cfile)) { + cfile->invalidHandle = true; + spin_unlock(&cfile->file_info_lock); + if (server->ops->close_dir) + server->ops->close_dir(xid, tcon, &cfile->fid); + } else + spin_unlock(&cfile->file_info_lock); + if (cfile->srch_inf.ntwrk_buf_start) { + cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n"); + if (cfile->srch_inf.smallBuf) + cifs_small_buf_release(cfile->srch_inf. + ntwrk_buf_start); + else + cifs_buf_release(cfile->srch_inf. + ntwrk_buf_start); + cfile->srch_inf.ntwrk_buf_start = NULL; + } + rc = initiate_cifs_search(xid, file, full_path); + if (rc) { + cifs_dbg(FYI, "error %d reinitiating a search on rewind\n", + rc); + return rc; + } + /* FindFirst/Next set last_entry to NULL on malformed reply */ + if (cfile->srch_inf.last_entry) + cifs_save_resume_key(cfile->srch_inf.last_entry, cfile); + } + + search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME; + if (backup_cred(cifs_sb)) + search_flags |= CIFS_SEARCH_BACKUP_SEARCH; + + while ((index_to_find >= cfile->srch_inf.index_of_last_entry) && + (rc == 0) && !cfile->srch_inf.endOfSearch) { + cifs_dbg(FYI, "calling findnext2\n"); + rc = server->ops->query_dir_next(xid, tcon, &cfile->fid, + search_flags, + &cfile->srch_inf); + /* FindFirst/Next set last_entry to NULL on malformed reply */ + if (cfile->srch_inf.last_entry) + cifs_save_resume_key(cfile->srch_inf.last_entry, cfile); + if (rc) + return -ENOENT; + } + if (index_to_find < cfile->srch_inf.index_of_last_entry) { + /* we found the buffer that contains the entry */ + /* scan and find it */ + int i; + char *cur_ent; + char *end_of_smb; + + if (cfile->srch_inf.ntwrk_buf_start == NULL) { + cifs_dbg(VFS, "ntwrk_buf_start is NULL during readdir\n"); + return -EIO; + } + + end_of_smb = cfile->srch_inf.ntwrk_buf_start + + server->ops->calc_smb_size( + cfile->srch_inf.ntwrk_buf_start); + + cur_ent = cfile->srch_inf.srch_entries_start; + first_entry_in_buffer = cfile->srch_inf.index_of_last_entry + - cfile->srch_inf.entries_in_buffer; + pos_in_buf = index_to_find - first_entry_in_buffer; + cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf); + + for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) { + /* go entry by entry figuring out which is first */ + cur_ent = nxt_dir_entry(cur_ent, end_of_smb, + cfile->srch_inf.info_level); + } + if ((cur_ent == NULL) && (i < pos_in_buf)) { + /* BB fixme - check if we should flag this error */ + cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n", + pos_in_buf, index_to_find, rc); + } + rc = 0; + *current_entry = cur_ent; + } else { + cifs_dbg(FYI, "index not in buffer - could not findnext into it\n"); + return 0; + } + + if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) { + cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n"); + *num_to_ret = 0; + } else + *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf; + + return rc; +} + +static bool emit_cached_dirents(struct cached_dirents *cde, + struct dir_context *ctx) +{ + struct cached_dirent *dirent; + bool rc; + + list_for_each_entry(dirent, &cde->entries, entry) { + /* + * Skip all early entries prior to the current lseek() + * position. + */ + if (ctx->pos > dirent->pos) + continue; + /* + * We recorded the current ->pos value for the dirent + * when we stored it in the cache. + * However, this sequence of ->pos values may have holes + * in it, for example dot-dirs returned from the server + * are suppressed. + * Handle this bu forcing ctx->pos to be the same as the + * ->pos of the current dirent we emit from the cache. + * This means that when we emit these entries from the cache + * we now emit them with the same ->pos value as in the + * initial scan. + */ + ctx->pos = dirent->pos; + rc = dir_emit(ctx, dirent->name, dirent->namelen, + dirent->fattr.cf_uniqueid, + dirent->fattr.cf_dtype); + if (!rc) + return rc; + ctx->pos++; + } + return true; +} + +static void update_cached_dirents_count(struct cached_dirents *cde, + struct dir_context *ctx) +{ + if (cde->ctx != ctx) + return; + if (cde->is_valid || cde->is_failed) + return; + + cde->pos++; +} + +static void finished_cached_dirents_count(struct cached_dirents *cde, + struct dir_context *ctx) +{ + if (cde->ctx != ctx) + return; + if (cde->is_valid || cde->is_failed) + return; + if (ctx->pos != cde->pos) + return; + + cde->is_valid = 1; +} + +static void add_cached_dirent(struct cached_dirents *cde, + struct dir_context *ctx, + const char *name, int namelen, + struct cifs_fattr *fattr) +{ + struct cached_dirent *de; + + if (cde->ctx != ctx) + return; + if (cde->is_valid || cde->is_failed) + return; + if (ctx->pos != cde->pos) { + cde->is_failed = 1; + return; + } + de = kzalloc(sizeof(*de), GFP_ATOMIC); + if (de == NULL) { + cde->is_failed = 1; + return; + } + de->namelen = namelen; + de->name = kstrndup(name, namelen, GFP_ATOMIC); + if (de->name == NULL) { + kfree(de); + cde->is_failed = 1; + return; + } + de->pos = ctx->pos; + + memcpy(&de->fattr, fattr, sizeof(struct cifs_fattr)); + + list_add_tail(&de->entry, &cde->entries); +} + +static bool cifs_dir_emit(struct dir_context *ctx, + const char *name, int namelen, + struct cifs_fattr *fattr, + struct cached_fid *cfid) +{ + bool rc; + ino_t ino = cifs_uniqueid_to_ino_t(fattr->cf_uniqueid); + + rc = dir_emit(ctx, name, namelen, ino, fattr->cf_dtype); + if (!rc) + return rc; + + if (cfid) { + mutex_lock(&cfid->dirents.de_mutex); + add_cached_dirent(&cfid->dirents, ctx, name, namelen, + fattr); + mutex_unlock(&cfid->dirents.de_mutex); + } + + return rc; +} + +static int cifs_filldir(char *find_entry, struct file *file, + struct dir_context *ctx, + char *scratch_buf, unsigned int max_len, + struct cached_fid *cfid) +{ + struct cifsFileInfo *file_info = file->private_data; + struct super_block *sb = file_inode(file)->i_sb; + struct cifs_sb_info *cifs_sb = CIFS_SB(sb); + struct cifs_dirent de = { NULL, }; + struct cifs_fattr fattr; + struct qstr name; + int rc = 0; + + rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level, + file_info->srch_inf.unicode); + if (rc) + return rc; + + if (de.namelen > max_len) { + cifs_dbg(VFS, "bad search response length %zd past smb end\n", + de.namelen); + return -EINVAL; + } + + /* skip . and .. since we added them first */ + if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode)) + return 0; + + if (file_info->srch_inf.unicode) { + struct nls_table *nlt = cifs_sb->local_nls; + int map_type; + + map_type = cifs_remap(cifs_sb); + name.name = scratch_buf; + name.len = + cifs_from_utf16((char *)name.name, (__le16 *)de.name, + UNICODE_NAME_MAX, + min_t(size_t, de.namelen, + (size_t)max_len), nlt, map_type); + name.len -= nls_nullsize(nlt); + } else { + name.name = de.name; + name.len = de.namelen; + } + + switch (file_info->srch_inf.info_level) { + case SMB_FIND_FILE_POSIX_INFO: + cifs_posix_to_fattr(&fattr, + (struct smb2_posix_info *)find_entry, + cifs_sb); + break; + case SMB_FIND_FILE_UNIX: + cifs_unix_basic_to_fattr(&fattr, + &((FILE_UNIX_INFO *)find_entry)->basic, + cifs_sb); + if (S_ISLNK(fattr.cf_mode)) + fattr.cf_flags |= CIFS_FATTR_NEED_REVAL; + break; + case SMB_FIND_FILE_INFO_STANDARD: + cifs_std_info_to_fattr(&fattr, + (FIND_FILE_STANDARD_INFO *)find_entry, + cifs_sb); + break; + case SMB_FIND_FILE_ID_FULL_DIR_INFO: + cifs_fulldir_info_to_fattr(&fattr, + (SEARCH_ID_FULL_DIR_INFO *)find_entry, + cifs_sb); + break; + default: + cifs_dir_info_to_fattr(&fattr, + (FILE_DIRECTORY_INFO *)find_entry, + cifs_sb); + break; + } + + if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) { + fattr.cf_uniqueid = de.ino; + } else { + fattr.cf_uniqueid = iunique(sb, ROOT_I); + cifs_autodisable_serverino(cifs_sb); + } + + if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) && + couldbe_mf_symlink(&fattr)) + /* + * trying to get the type and mode can be slow, + * so just call those regular files for now, and mark + * for reval + */ + fattr.cf_flags |= CIFS_FATTR_NEED_REVAL; + + cifs_prime_dcache(file_dentry(file), &name, &fattr); + + return !cifs_dir_emit(ctx, name.name, name.len, + &fattr, cfid); +} + + +int cifs_readdir(struct file *file, struct dir_context *ctx) +{ + int rc = 0; + unsigned int xid; + int i; + struct tcon_link *tlink = NULL; + struct cifs_tcon *tcon; + struct cifsFileInfo *cifsFile; + char *current_entry; + int num_to_fill = 0; + char *tmp_buf = NULL; + char *end_of_smb; + unsigned int max_len; + const char *full_path; + void *page = alloc_dentry_path(); + struct cached_fid *cfid = NULL; + struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file); + + xid = get_xid(); + + full_path = build_path_from_dentry(file_dentry(file), page); + if (IS_ERR(full_path)) { + rc = PTR_ERR(full_path); + goto rddir2_exit; + } + + if (file->private_data == NULL) { + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) + goto cache_not_found; + tcon = tlink_tcon(tlink); + } else { + cifsFile = file->private_data; + tcon = tlink_tcon(cifsFile->tlink); + } + + rc = open_cached_dir(xid, tcon, full_path, cifs_sb, false, &cfid); + cifs_put_tlink(tlink); + if (rc) + goto cache_not_found; + + mutex_lock(&cfid->dirents.de_mutex); + /* + * If this was reading from the start of the directory + * we need to initialize scanning and storing the + * directory content. + */ + if (ctx->pos == 0 && cfid->dirents.ctx == NULL) { + cfid->dirents.ctx = ctx; + cfid->dirents.pos = 2; + } + /* + * If we already have the entire directory cached then + * we can just serve the cache. + */ + if (cfid->dirents.is_valid) { + if (!dir_emit_dots(file, ctx)) { + mutex_unlock(&cfid->dirents.de_mutex); + goto rddir2_exit; + } + emit_cached_dirents(&cfid->dirents, ctx); + mutex_unlock(&cfid->dirents.de_mutex); + goto rddir2_exit; + } + mutex_unlock(&cfid->dirents.de_mutex); + + /* Drop the cache while calling initiate_cifs_search and + * find_cifs_entry in case there will be reconnects during + * query_directory. + */ + close_cached_dir(cfid); + cfid = NULL; + + cache_not_found: + /* + * Ensure FindFirst doesn't fail before doing filldir() for '.' and + * '..'. Otherwise we won't be able to notify VFS in case of failure. + */ + if (file->private_data == NULL) { + rc = initiate_cifs_search(xid, file, full_path); + cifs_dbg(FYI, "initiate cifs search rc %d\n", rc); + if (rc) + goto rddir2_exit; + } + + if (!dir_emit_dots(file, ctx)) + goto rddir2_exit; + + /* 1) If search is active, + is in current search buffer? + if it before then restart search + if after then keep searching till find it */ + cifsFile = file->private_data; + if (cifsFile->srch_inf.endOfSearch) { + if (cifsFile->srch_inf.emptyDir) { + cifs_dbg(FYI, "End of search, empty dir\n"); + rc = 0; + goto rddir2_exit; + } + } /* else { + cifsFile->invalidHandle = true; + tcon->ses->server->close(xid, tcon, &cifsFile->fid); + } */ + + tcon = tlink_tcon(cifsFile->tlink); + rc = find_cifs_entry(xid, tcon, ctx->pos, file, full_path, + ¤t_entry, &num_to_fill); + open_cached_dir(xid, tcon, full_path, cifs_sb, false, &cfid); + if (rc) { + cifs_dbg(FYI, "fce error %d\n", rc); + goto rddir2_exit; + } else if (current_entry != NULL) { + cifs_dbg(FYI, "entry %lld found\n", ctx->pos); + } else { + if (cfid) { + mutex_lock(&cfid->dirents.de_mutex); + finished_cached_dirents_count(&cfid->dirents, ctx); + mutex_unlock(&cfid->dirents.de_mutex); + } + cifs_dbg(FYI, "Could not find entry\n"); + goto rddir2_exit; + } + cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n", + num_to_fill, cifsFile->srch_inf.ntwrk_buf_start); + max_len = tcon->ses->server->ops->calc_smb_size( + cifsFile->srch_inf.ntwrk_buf_start); + end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len; + + tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL); + if (tmp_buf == NULL) { + rc = -ENOMEM; + goto rddir2_exit; + } + + for (i = 0; i < num_to_fill; i++) { + if (current_entry == NULL) { + /* evaluate whether this case is an error */ + cifs_dbg(VFS, "past SMB end, num to fill %d i %d\n", + num_to_fill, i); + break; + } + /* + * if buggy server returns . and .. late do we want to + * check for that here? + */ + *tmp_buf = 0; + rc = cifs_filldir(current_entry, file, ctx, + tmp_buf, max_len, cfid); + if (rc) { + if (rc > 0) + rc = 0; + break; + } + + ctx->pos++; + if (cfid) { + mutex_lock(&cfid->dirents.de_mutex); + update_cached_dirents_count(&cfid->dirents, ctx); + mutex_unlock(&cfid->dirents.de_mutex); + } + + if (ctx->pos == + cifsFile->srch_inf.index_of_last_entry) { + cifs_dbg(FYI, "last entry in buf at pos %lld %s\n", + ctx->pos, tmp_buf); + cifs_save_resume_key(current_entry, cifsFile); + break; + } + current_entry = + nxt_dir_entry(current_entry, end_of_smb, + cifsFile->srch_inf.info_level); + } + kfree(tmp_buf); + +rddir2_exit: + if (cfid) + close_cached_dir(cfid); + free_dentry_path(page); + free_xid(xid); + return rc; +} |