From c22870ea2deb2841402133909cfa707a2c0b12ed Mon Sep 17 00:00:00 2001 From: Steve French Date: Tue, 16 Sep 2014 07:18:19 -0500 Subject: [PATCH] mfsymlinks support for SMB2.1/SMB3. Part 2 query symlink Adds support on SMB2.1 and SMB3 mounts for emulation of symlinks via the "Minshall/French" symlink format already used for cifs mounts when mfsymlinks mount option is used (and also used by Apple). http://wiki.samba.org/index.php/UNIX_Extensions#Minshall.2BFrench_symlinks This second patch adds support to query them (recognize them as symlinks and read them). Third version of patch makes minor corrections to error handling. Signed-off-by: Steve French Reviewed-by: Stefan Metzmacher --- fs/cifs/link.c | 70 ++++++++++++++++++++++++++++++++++++++++++++- fs/cifs/smb2ops.c | 2 ++ fs/cifs/smb2proto.h | 4 +++ 3 files changed, 75 insertions(+), 1 deletion(-) diff --git a/fs/cifs/link.c b/fs/cifs/link.c index 1216f4f1c6c9..ce7d4bbf3120 100644 --- a/fs/cifs/link.c +++ b/fs/cifs/link.c @@ -28,7 +28,9 @@ #include "cifsproto.h" #include "cifs_debug.h" #include "cifs_fs_sb.h" +#ifdef CONFIG_CIFS_SMB2 #include "smb2proto.h" +#endif /* * M-F Symlink Functions - Begin @@ -401,6 +403,72 @@ cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, return rc; } +/* + * SMB 2.1/SMB3 Protocol specific functions + */ +#ifdef CONFIG_CIFS_SMB2 +int +smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, const unsigned char *path, + char *pbuf, unsigned int *pbytes_read) +{ + int rc; + struct cifs_fid fid; + struct cifs_open_parms oparms; + struct cifs_io_parms io_parms; + int buf_type = CIFS_NO_BUFFER; + __le16 *utf16_path; + __u8 oplock = SMB2_OPLOCK_LEVEL_II; + struct smb2_file_all_info *pfile_info = NULL; + + oparms.tcon = tcon; + oparms.cifs_sb = cifs_sb; + oparms.desired_access = GENERIC_READ; + oparms.create_options = CREATE_NOT_DIR; + if (backup_cred(cifs_sb)) + oparms.create_options |= CREATE_OPEN_BACKUP_INTENT; + oparms.disposition = FILE_OPEN; + oparms.fid = &fid; + oparms.reconnect = false; + + utf16_path = cifs_convert_path_to_utf16(path, cifs_sb); + if (utf16_path == NULL) + return -ENOMEM; + + pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2, + GFP_KERNEL); + + if (pfile_info == NULL) { + kfree(utf16_path); + return -ENOMEM; + } + + rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL); + if (rc) + goto qmf_out_open_fail; + + if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) { + /* it's not a symlink */ + rc = -ENOENT; /* Is there a better rc to return? */ + goto qmf_out; + } + + io_parms.netfid = fid.netfid; + io_parms.pid = current->tgid; + io_parms.tcon = tcon; + io_parms.offset = 0; + io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE; + io_parms.persistent_fid = fid.persistent_fid; + io_parms.volatile_fid = fid.volatile_fid; + rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type); +qmf_out: + SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid); +qmf_out_open_fail: + kfree(utf16_path); + kfree(pfile_info); + return rc; +} + int smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, struct cifs_sb_info *cifs_sb, const unsigned char *path, @@ -461,7 +529,7 @@ smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, kfree(utf16_path); return rc; } - +#endif /* CONFIG_CIFS_SMB2 */ /* * M-F Symlink Functions - End diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 5e35d51504fd..af446866cbe8 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -1452,6 +1452,7 @@ struct smb_version_operations smb21_operations = { .rename = smb2_rename_path, .create_hardlink = smb2_create_hardlink, .query_symlink = smb2_query_symlink, + .query_mf_symlink = smb3_query_mf_symlink, .create_mf_symlink = smb3_create_mf_symlink, .open = smb2_open_file, .set_fid = smb2_set_fid, @@ -1532,6 +1533,7 @@ struct smb_version_operations smb30_operations = { .rename = smb2_rename_path, .create_hardlink = smb2_create_hardlink, .query_symlink = smb2_query_symlink, + .query_mf_symlink = smb3_query_mf_symlink, .create_mf_symlink = smb3_create_mf_symlink, .open = smb2_open_file, .set_fid = smb2_set_fid, diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h index e144ecfaa797..79dc650c18b2 100644 --- a/fs/cifs/smb2proto.h +++ b/fs/cifs/smb2proto.h @@ -85,6 +85,10 @@ extern int smb2_create_hardlink(const unsigned int xid, struct cifs_tcon *tcon, extern int smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, struct cifs_sb_info *cifs_sb, const unsigned char *path, char *pbuf, unsigned int *pbytes_written); +extern int smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, + const unsigned char *path, char *pbuf, + unsigned int *pbytes_read); extern int smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms, __u32 *oplock, FILE_ALL_INFO *buf); -- 2.20.1