From: Aurelien Aptel <aaptel@suse.com>
Date: Mon, 18 Nov 2019 21:04:08 +0100
Subject: [PATCH] CIFS: refactor cifs_get_inode_info()
Git-commit: b8f7442bc46e48fb6fe5d7bc3e1ac1500ce649a9
References: bsc#1144333
Patch-mainline: v5.5-rc1
Make logic of cifs_get_inode() much clearer by moving code to sub
functions and adding comments.
Document the steps this function does.
cifs_get_inode_info() gets and updates a file inode metadata from its
file path.
* If caller already has raw info data from server they can pass it.
* If inode already exists (just need to update) caller can pass it.
Step 1: get raw data from server if none was passed
Step 2: parse raw data into intermediate internal cifs_fattr struct
Step 3: set fattr uniqueid which is later used for inode number. This
can sometime be done from raw data
Step 4: tweak fattr according to mount options (file_mode, acl to mode
bits, uid, gid, etc)
Step 5: update or create inode from final fattr struct
* add is_smb1_server() helper
* add is_inode_cache_good() helper
* move SMB1-backupcreds-getinfo-retry to separate func
cifs_backup_query_path_info().
* move set-uniqueid code to separate func cifs_set_fattr_ino()
* don't clobber uniqueid from backup cred retry
* fix some probable corner cases memleaks
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Paulo Alcantara <palcantara@suse.de>
---
fs/cifs/cifsglob.h | 6 +
fs/cifs/inode.c | 340 +++++++++++++++++++++++++++------------------
2 files changed, 207 insertions(+), 139 deletions(-)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 478b913f6f79..6bd917b4ee1d 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1967,4 +1967,10 @@ extern struct smb_version_values smb302_values;
#define ALT_SMB311_VERSION_STRING "3.11"
extern struct smb_version_operations smb311_operations;
extern struct smb_version_values smb311_values;
+
+static inline bool is_smb1_server(struct TCP_Server_Info *server)
+{
+ return strcmp(server->vals->version_string, SMB1_VERSION_STRING) == 0;
+}
+
#endif /* _CIFS_GLOB_H */
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index df9377828e2f..1fec2e7d796a 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -727,22 +727,138 @@ static __u64 simple_hashstr(const char *str)
return hash;
}
+/**
+ * cifs_backup_query_path_info - SMB1 fallback code to get ino
+ *
+ * Fallback code to get file metadata when we don't have access to
+ * @full_path (EACCESS) and have backup creds.
+ *
+ * @data will be set to search info result buffer
+ * @resp_buf will be set to cifs resp buf and needs to be freed with
+ * cifs_buf_release() when done with @data.
+ */
+static int
+cifs_backup_query_path_info(int xid,
+ struct cifs_tcon *tcon,
+ struct super_block *sb,
+ const char *full_path,
+ void **resp_buf,
+ FILE_ALL_INFO **data)
+{
+ struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
+ struct cifs_search_info info = {0};
+ u16 flags;
+ int rc;
+
+ *resp_buf = NULL;
+ info.endOfSearch = false;
+ if (tcon->unix_ext)
+ info.info_level = SMB_FIND_FILE_UNIX;
+ else if ((tcon->ses->capabilities &
+ tcon->ses->server->vals->cap_nt_find) == 0)
+ info.info_level = SMB_FIND_FILE_INFO_STANDARD;
+ else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)
+ info.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
+ else /* no srvino useful for fallback to some netapp */
+ info.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
+
+ flags = CIFS_SEARCH_CLOSE_ALWAYS |
+ CIFS_SEARCH_CLOSE_AT_END |
+ CIFS_SEARCH_BACKUP_SEARCH;
+
+ rc = CIFSFindFirst(xid, tcon, full_path,
+ cifs_sb, NULL, flags, &info, false);
+ if (rc)
+ return rc;
+
+ *resp_buf = (void *)info.ntwrk_buf_start;
+ *data = (FILE_ALL_INFO *)info.srch_entries_start;
+ return 0;
+}
+
+static void
+cifs_set_fattr_ino(int xid,
+ struct cifs_tcon *tcon,
+ struct super_block *sb,
+ struct inode **inode,
+ const char *full_path,
+ FILE_ALL_INFO *data,
+ struct cifs_fattr *fattr)
+{
+ struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
+ struct TCP_Server_Info *server = tcon->ses->server;
+ int rc;
+
+ if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
+ if (*inode)
+ fattr->cf_uniqueid = CIFS_I(*inode)->uniqueid;
+ else
+ fattr->cf_uniqueid = iunique(sb, ROOT_I);
+ return;
+ }
+
+ /*
+ * If we have an inode pass a NULL tcon to ensure we don't
+ * make a round trip to the server. This only works for SMB2+.
+ */
+ rc = server->ops->get_srv_inum(xid,
+ *inode ? NULL : tcon,
+ cifs_sb, full_path,
+ &fattr->cf_uniqueid,
+ data);
+ if (rc) {
+ /*
+ * If that fails reuse existing ino or generate one
+ * and disable server ones
+ */
+ if (*inode)
+ fattr->cf_uniqueid = CIFS_I(*inode)->uniqueid;
+ else {
+ fattr->cf_uniqueid = iunique(sb, ROOT_I);
+ cifs_autodisable_serverino(cifs_sb);
+ }
+ return;
+ }
+
+ /* If no errors, check for zero root inode (invalid) */
+ if (fattr->cf_uniqueid == 0 && strlen(full_path) == 0) {
+ cifs_dbg(FYI, "Invalid (0) inodenum\n");
+ if (*inode) {
+ /* reuse */
+ fattr->cf_uniqueid = CIFS_I(*inode)->uniqueid;
+ } else {
+ /* make an ino by hashing the UNC */
+ fattr->cf_flags |= CIFS_FATTR_FAKE_ROOT_INO;
+ fattr->cf_uniqueid = simple_hashstr(tcon->treeName);
+ }
+ }
+}
+
+static inline bool is_inode_cache_good(struct inode *ino)
+{
+ return ino && CIFS_CACHE_READ(CIFS_I(ino)) && CIFS_I(ino)->time != 0;
+}
+
int
-cifs_get_inode_info(struct inode **inode, const char *full_path,
- FILE_ALL_INFO *data, struct super_block *sb, int xid,
+cifs_get_inode_info(struct inode **inode,
+ const char *full_path,
+ FILE_ALL_INFO *in_data,
+ struct super_block *sb, int xid,
const struct cifs_fid *fid)
{
- __u16 srchflgs;
- int rc = 0, tmprc = ENOSYS;
+
struct cifs_tcon *tcon;
struct TCP_Server_Info *server;
struct tcon_link *tlink;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
- char *buf = NULL;
bool adjust_tz = false;
- struct cifs_fattr fattr;
- struct cifs_search_info *srchinf = NULL;
+ struct cifs_fattr fattr = {0};
bool symlink = false;
+ FILE_ALL_INFO *data = in_data;
+ FILE_ALL_INFO *tmp_data = NULL;
+ void *smb1_backup_rsp_buf = NULL;
+ int rc = 0;
+ int tmprc = 0;
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink))
@@ -750,142 +866,88 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
tcon = tlink_tcon(tlink);
server = tcon->ses->server;
- cifs_dbg(FYI, "Getting info on %s\n", full_path);
+ /*
+ * 1. Fetch file metadata if not provided (data)
+ */
- if ((data == NULL) && (*inode != NULL)) {
- if (CIFS_CACHE_READ(CIFS_I(*inode)) &&
- CIFS_I(*inode)->time != 0) {
+ if (!data) {
+ if (is_inode_cache_good(*inode)) {
cifs_dbg(FYI, "No need to revalidate cached inode sizes\n");
- goto cgii_exit;
+ goto out;
}
- }
-
- /* if inode info is not passed, get it from server */
- if (data == NULL) {
- if (!server->ops->query_path_info) {
- rc = -ENOSYS;
- goto cgii_exit;
- }
- buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
- if (buf == NULL) {
+ tmp_data = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
+ if (!tmp_data) {
rc = -ENOMEM;
- goto cgii_exit;
+ goto out;
}
- data = (FILE_ALL_INFO *)buf;
- rc = server->ops->query_path_info(xid, tcon, cifs_sb, full_path,
- data, &adjust_tz, &symlink);
+ rc = server->ops->query_path_info(xid, tcon, cifs_sb,
+ full_path, tmp_data,
+ &adjust_tz, &symlink);
+ data = tmp_data;
}
- if (!rc) {
- cifs_all_info_to_fattr(&fattr, data, sb, adjust_tz,
- symlink);
- } else if (rc == -EREMOTE) {
+ /*
+ * 2. Convert it to internal cifs metadata (fattr)
+ */
+
+ switch (rc) {
+ case 0:
+ cifs_all_info_to_fattr(&fattr, data, sb, adjust_tz, symlink);
+ break;
+ case -EREMOTE:
+ /* DFS link, no metadata available on this server */
cifs_create_dfs_fattr(&fattr, sb);
rc = 0;
- } else if ((rc == -EACCES) && backup_cred(cifs_sb) &&
- (strcmp(server->vals->version_string, SMB1_VERSION_STRING)
- == 0)) {
+ break;
+ case -EACCES:
/*
- * For SMB2 and later the backup intent flag is already
- * sent if needed on open and there is no path based
- * FindFirst operation to use to retry with
+ * perm errors, try again with backup flags if possible
+ *
+ * For SMB2 and later the backup intent flag
+ * is already sent if needed on open and there
+ * is no path based FindFirst operation to use
+ * to retry with
*/
+ if (backup_cred(cifs_sb) && is_smb1_server(server)) {
+ /* for easier reading */
+ FILE_DIRECTORY_INFO *fdi;
+ SEARCH_ID_FULL_DIR_INFO *si;
- srchinf = kzalloc(sizeof(struct cifs_search_info),
- GFP_KERNEL);
- if (srchinf == NULL) {
- rc = -ENOMEM;
- goto cgii_exit;
- }
-
- srchinf->endOfSearch = false;
- if (tcon->unix_ext)
- srchinf->info_level = SMB_FIND_FILE_UNIX;
- else if ((tcon->ses->capabilities &
- tcon->ses->server->vals->cap_nt_find) == 0)
- srchinf->info_level = SMB_FIND_FILE_INFO_STANDARD;
- else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)
- srchinf->info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
- else /* no srvino useful for fallback to some netapp */
- srchinf->info_level = SMB_FIND_FILE_DIRECTORY_INFO;
-
- srchflgs = CIFS_SEARCH_CLOSE_ALWAYS |
- CIFS_SEARCH_CLOSE_AT_END |
- CIFS_SEARCH_BACKUP_SEARCH;
+ rc = cifs_backup_query_path_info(xid, tcon, sb,
+ full_path,
+ &smb1_backup_rsp_buf,
+ &data);
+ if (rc)
+ goto out;
- rc = CIFSFindFirst(xid, tcon, full_path,
- cifs_sb, NULL, srchflgs, srchinf, false);
- if (!rc) {
- data = (FILE_ALL_INFO *)srchinf->srch_entries_start;
+ fdi = (FILE_DIRECTORY_INFO *)data;
+ si = (SEARCH_ID_FULL_DIR_INFO *)data;
- cifs_dir_info_to_fattr(&fattr,
- (FILE_DIRECTORY_INFO *)data, cifs_sb);
- fattr.cf_uniqueid = le64_to_cpu(
- ((SEARCH_ID_FULL_DIR_INFO *)data)->UniqueId);
-
- cifs_buf_release(srchinf->ntwrk_buf_start);
+ cifs_dir_info_to_fattr(&fattr, fdi, cifs_sb);
+ fattr.cf_uniqueid = le64_to_cpu(si->UniqueId);
+ /* uniqueid set, skip get inum step */
+ goto handle_mnt_opt;
+ } else {
+ /* nothing we can do, bail out */
+ goto out;
}
- kfree(srchinf);
- if (rc)
- goto cgii_exit;
- } else
- goto cgii_exit;
-
- /*
- * If an inode wasn't passed in, then get the inode number
- *
- * Is an i_ino of zero legal? Can we use that to check if the server
- * supports returning inode numbers? Are there other sanity checks we
- * can use to ensure that the server is really filling in that field?
- */
- if (*inode == NULL) {
- if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
- if (server->ops->get_srv_inum)
- tmprc = server->ops->get_srv_inum(xid,
- tcon, cifs_sb, full_path,
- &fattr.cf_uniqueid, data);
- if (tmprc) {
- cifs_dbg(FYI, "GetSrvInodeNum rc %d\n",
- tmprc);
- fattr.cf_uniqueid = iunique(sb, ROOT_I);
- cifs_autodisable_serverino(cifs_sb);
- } else if ((fattr.cf_uniqueid == 0) &&
- strlen(full_path) == 0) {
- /* some servers ret bad root ino ie 0 */
- cifs_dbg(FYI, "Invalid (0) inodenum\n");
- fattr.cf_flags |=
- CIFS_FATTR_FAKE_ROOT_INO;
- fattr.cf_uniqueid =
- simple_hashstr(tcon->treeName);
- }
- } else
- fattr.cf_uniqueid = iunique(sb, ROOT_I);
- } else {
- if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)
- && server->ops->get_srv_inum) {
- /*
- * Pass a NULL tcon to ensure we don't make a round
- * trip to the server. This only works for SMB2+.
- */
- tmprc = server->ops->get_srv_inum(xid,
- NULL, cifs_sb, full_path,
- &fattr.cf_uniqueid, data);
- if (tmprc)
- fattr.cf_uniqueid = CIFS_I(*inode)->uniqueid;
- else if ((fattr.cf_uniqueid == 0) &&
- strlen(full_path) == 0) {
- /*
- * Reuse existing root inode num since
- * inum zero for root causes ls of . and .. to
- * not be returned
- */
- cifs_dbg(FYI, "Srv ret 0 inode num for root\n");
- fattr.cf_uniqueid = CIFS_I(*inode)->uniqueid;
- }
- } else
- fattr.cf_uniqueid = CIFS_I(*inode)->uniqueid;
+ break;
+ default:
+ cifs_dbg(FYI, "%s: unhandled err rc %d\n", __func__, rc);
+ goto out;
}
+ /*
+ * 3. Get or update inode number (fattr.cf_uniqueid)
+ */
+
+ cifs_set_fattr_ino(xid, tcon, sb, inode, full_path, data, &fattr);
+
+ /*
+ * 4. Tweak fattr based on mount options
+ */
+
+handle_mnt_opt:
/* query for SFU type info if supported and needed */
if (fattr.cf_cifsattrs & ATTR_SYSTEM &&
cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
@@ -900,16 +962,15 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
full_path, fid);
if (rc) {
cifs_dbg(FYI, "%s: Get mode from SID failed. rc=%d\n",
- __func__, rc);
- goto cgii_exit;
+ __func__, rc);
+ goto out;
}
} else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
rc = cifs_acl_to_fattr(cifs_sb, &fattr, *inode, false,
- full_path, fid);
- if (rc) {
+ full_path, fid); if (rc) {
cifs_dbg(FYI, "%s: Getting ACL failed with error: %d\n",
__func__, rc);
- goto cgii_exit;
+ goto out;
}
}
@@ -925,6 +986,10 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
cifs_dbg(FYI, "check_mf_symlink: %d\n", tmprc);
}
+ /*
+ * 5. Update inode with final fattr data
+ */
+
if (!*inode) {
*inode = cifs_iget(sb, &fattr);
if (!*inode)
@@ -937,7 +1002,7 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
CIFS_I(*inode)->uniqueid != fattr.cf_uniqueid)) {
CIFS_I(*inode)->time = 0; /* force reval */
rc = -ESTALE;
- goto cgii_exit;
+ goto out;
}
/* if filetype is different, return error */
@@ -945,18 +1010,15 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
(fattr.cf_mode & S_IFMT))) {
CIFS_I(*inode)->time = 0; /* force reval */
rc = -ESTALE;
- goto cgii_exit;
+ goto out;
}
cifs_fattr_to_inode(*inode, &fattr);
}
-
-cgii_exit:
- if ((*inode) && ((*inode)->i_ino == 0))
- cifs_dbg(FYI, "inode number of zero returned\n");
-
- kfree(buf);
+out:
+ cifs_buf_release(smb1_backup_rsp_buf);
cifs_put_tlink(tlink);
+ kfree(tmp_data);
return rc;
}
--
2.25.1