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author | 2022-10-03 18:43:50 -0300 | |
---|---|---|
committer | 2022-10-13 09:36:04 -0500 | |
commit | 76894f3e2f71177747b8b4763fb180e800279585 (patch) | |
tree | d0382d6389d324b5d7421ee960a60af74415b631 /fs/cifs/link.c | |
parent | smb3: clarify multichannel warning (diff) | |
download | linux-76894f3e2f71177747b8b4763fb180e800279585.tar.gz linux-76894f3e2f71177747b8b4763fb180e800279585.tar.bz2 linux-76894f3e2f71177747b8b4763fb180e800279585.zip |
cifs: improve symlink handling for smb2+
When creating inode for symlink, the client used to send below
requests to fill it in:
* create+query_info+close (STATUS_STOPPED_ON_SYMLINK)
* create(+reparse_flag)+query_info+close (set file attrs)
* create+ioctl(get_reparse)+close (query reparse tag)
and then for every access to the symlink dentry, the ->link() method
would send another:
* create+ioctl(get_reparse)+close (parse symlink)
So, in order to improve:
(i) Get rid of unnecessary roundtrips and then resolve symlinks as
follows:
* create+query_info+close (STATUS_STOPPED_ON_SYMLINK +
parse symlink + get reparse tag)
* create(+reparse_flag)+query_info+close (set file attrs)
(ii) Set the resolved symlink target directly in inode->i_link and
use simple_get_link() for ->link() to simply return it.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/cifs/link.c')
-rw-r--r-- | fs/cifs/link.c | 107 |
1 files changed, 3 insertions, 104 deletions
diff --git a/fs/cifs/link.c b/fs/cifs/link.c index cd29c296cec6..bd374feeccaa 100644 --- a/fs/cifs/link.c +++ b/fs/cifs/link.c @@ -201,40 +201,6 @@ out: return rc; } -static int -query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon, - struct cifs_sb_info *cifs_sb, const unsigned char *path, - char **symlinkinfo) -{ - int rc; - u8 *buf = NULL; - unsigned int link_len = 0; - unsigned int bytes_read = 0; - - buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - if (tcon->ses->server->ops->query_mf_symlink) - rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon, - cifs_sb, path, buf, &bytes_read); - else - rc = -ENOSYS; - - if (rc) - goto out; - - if (bytes_read == 0) { /* not a symlink */ - rc = -EINVAL; - goto out; - } - - rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo); -out: - kfree(buf); - return rc; -} - int check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr, @@ -244,6 +210,7 @@ check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, u8 *buf = NULL; unsigned int link_len = 0; unsigned int bytes_read = 0; + char *symlink = NULL; if (!couldbe_mf_symlink(fattr)) /* it's not a symlink */ @@ -265,7 +232,7 @@ check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, if (bytes_read == 0) /* not a symlink */ goto out; - rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL); + rc = parse_mf_symlink(buf, bytes_read, &link_len, &symlink); if (rc == -EINVAL) { /* it's not a symlink */ rc = 0; @@ -280,6 +247,7 @@ check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, fattr->cf_mode &= ~S_IFMT; fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO; fattr->cf_dtype = DT_LNK; + fattr->cf_symlink_target = symlink; out: kfree(buf); return rc; @@ -599,75 +567,6 @@ cifs_hl_exit: return rc; } -const char * -cifs_get_link(struct dentry *direntry, struct inode *inode, - struct delayed_call *done) -{ - int rc = -ENOMEM; - unsigned int xid; - const char *full_path; - void *page; - char *target_path = NULL; - struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); - struct tcon_link *tlink = NULL; - struct cifs_tcon *tcon; - struct TCP_Server_Info *server; - - if (!direntry) - return ERR_PTR(-ECHILD); - - xid = get_xid(); - - tlink = cifs_sb_tlink(cifs_sb); - if (IS_ERR(tlink)) { - free_xid(xid); - return ERR_CAST(tlink); - } - tcon = tlink_tcon(tlink); - server = tcon->ses->server; - - page = alloc_dentry_path(); - full_path = build_path_from_dentry(direntry, page); - if (IS_ERR(full_path)) { - free_xid(xid); - cifs_put_tlink(tlink); - free_dentry_path(page); - return ERR_CAST(full_path); - } - - cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode); - - rc = -EACCES; - /* - * First try Minshall+French Symlinks, if configured - * and fallback to UNIX Extensions Symlinks. - */ - if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) - rc = query_mf_symlink(xid, tcon, cifs_sb, full_path, - &target_path); - - if (rc != 0 && server->ops->query_symlink) { - struct cifsInodeInfo *cifsi = CIFS_I(inode); - bool reparse_point = false; - - if (cifsi->cifsAttrs & ATTR_REPARSE) - reparse_point = true; - - rc = server->ops->query_symlink(xid, tcon, cifs_sb, full_path, - &target_path, reparse_point); - } - - free_dentry_path(page); - free_xid(xid); - cifs_put_tlink(tlink); - if (rc != 0) { - kfree(target_path); - return ERR_PTR(rc); - } - set_delayed_call(done, kfree_link, target_path); - return target_path; -} - int cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode, struct dentry *direntry, const char *symname) |