cifs: add new cifs_iget function and convert unix codepath to use it

cifs: add new cifs_iget function and convert unix codepath to use it

In order to unify some codepaths, introduce a common cifs_fattr struct
for storing inode attributes. The different codepaths (unix, legacy,
normal, etc...) can fill out this struct with inode info. It can then be
passed as an arg to a common set of routines to get and update inodes.

Add a new cifs_iget function that uses iget5_locked to identify inodes.
This will compare inodes based on the uniqueid value in a cifs_fattr
struct.

Rather than filling out an already-created inode, have
cifs_get_inode_info_unix instead fill out cifs_fattr and hand that off
to cifs_iget. cifs_iget can then properly look for hardlinked inodes.

On the readdir side, add a new cifs_readdir_lookup function that spawns
populated dentries. Redefine FILE_UNIX_INFO so that it's basically a
FILE_UNIX_BASIC_INFO that has a few fields wrapped around it. This
allows us to more easily use the same function for filling out the fattr
as the non-readdir codepath.

With this, we should then have proper hardlink detection and can
eventually get rid of some nasty CIFS-specific hacks for handing them.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 192 insertions, 188 deletions

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 155c9e785d0c..b22379610d71 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -77,127 +77,146 @@ static void cifs_set_ops(struct inode *inode, const bool is_dfs_referral)
         }
 }
 
-static void cifs_unix_info_to_inode(struct inode *inode,
-                FILE_UNIX_BASIC_INFO *info, int force_uid_gid)
+/* populate an inode with info from a cifs_fattr struct */
+void
+cifs_fattr_to_inode(struct inode *inode, struct cifs_fattr *fattr)
 {
-        struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
-        struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
-        __u64 num_of_bytes = le64_to_cpu(info->NumOfBytes);
-        __u64 end_of_file = le64_to_cpu(info->EndOfFile);
+        struct cifsInodeInfo *cifs_i = CIFS_I(inode);
+        unsigned long now = jiffies;
+
+        inode->i_atime = fattr->cf_atime;
+        inode->i_mtime = fattr->cf_mtime;
+        inode->i_ctime = fattr->cf_ctime;
+        inode->i_mode = fattr->cf_mode;
+        inode->i_rdev = fattr->cf_rdev;
+        inode->i_nlink = fattr->cf_nlink;
+        inode->i_uid = fattr->cf_uid;
+        inode->i_gid = fattr->cf_gid;
+
+        cifs_i->cifsAttrs = fattr->cf_cifsattrs;
+        cifs_i->uniqueid = fattr->cf_uniqueid;
+
+        cFYI(1, ("inode 0x%p old_time=%ld new_time=%ld", inode,
+                 cifs_i->time, now));
+        cifs_i->time = now;
+
+        /*
+         * Can't safely change the file size here if the client is writing to
+         * it due to potential races.
+         */
+        spin_lock(&inode->i_lock);
+        if (is_size_safe_to_change(cifs_i, fattr->cf_eof)) {
+                i_size_write(inode, fattr->cf_eof);
+
+                /*
+                 * i_blocks is not related to (i_size / i_blksize),
+                 * but instead 512 byte (2**9) size is required for
+                 * calculating num blocks.
+                 */
+                inode->i_blocks = (512 - 1 + fattr->cf_bytes) >> 9;
+        }
+        spin_unlock(&inode->i_lock);
+
+        cifs_set_ops(inode, fattr->cf_flags & CIFS_FATTR_DFS_REFERRAL);
+}
+
+/* Fill a cifs_fattr struct with info from FILE_UNIX_BASIC_INFO. */
+void
+cifs_unix_basic_to_fattr(struct cifs_fattr *fattr, FILE_UNIX_BASIC_INFO *info,
+                         struct cifs_sb_info *cifs_sb)
+{
+        memset(fattr, 0, sizeof(*fattr));
+        fattr->cf_uniqueid = le64_to_cpu(info->UniqueId);
+        fattr->cf_bytes = le64_to_cpu(info->NumOfBytes);
+        fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 
-        inode->i_atime = cifs_NTtimeToUnix(info->LastAccessTime);
-        inode->i_mtime =
-                cifs_NTtimeToUnix(info->LastModificationTime);
-        inode->i_ctime = cifs_NTtimeToUnix(info->LastStatusChange);
-        inode->i_mode = le64_to_cpu(info->Permissions);
+        fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
+        fattr->cf_mtime = cifs_NTtimeToUnix(info->LastModificationTime);
+        fattr->cf_ctime = cifs_NTtimeToUnix(info->LastStatusChange);
+        fattr->cf_mode = le64_to_cpu(info->Permissions);
 
         /*
          * Since we set the inode type below we need to mask off
          * to avoid strange results if bits set above.
          */
-        inode->i_mode &= ~S_IFMT;
+        fattr->cf_mode &= ~S_IFMT;
         switch (le32_to_cpu(info->Type)) {
         case UNIX_FILE:
-                inode->i_mode |= S_IFREG;
+                fattr->cf_mode |= S_IFREG;
+                fattr->cf_dtype = DT_REG;
                 break;
         case UNIX_SYMLINK:
-                inode->i_mode |= S_IFLNK;
+                fattr->cf_mode |= S_IFLNK;
+                fattr->cf_dtype = DT_LNK;
                 break;
         case UNIX_DIR:
-                inode->i_mode |= S_IFDIR;
+                fattr->cf_mode |= S_IFDIR;
+                fattr->cf_dtype = DT_DIR;
                 break;
         case UNIX_CHARDEV:
-                inode->i_mode |= S_IFCHR;
-                inode->i_rdev = MKDEV(le64_to_cpu(info->DevMajor),
-                                      le64_to_cpu(info->DevMinor) & MINORMASK);
+                fattr->cf_mode |= S_IFCHR;
+                fattr->cf_dtype = DT_CHR;
+                fattr->cf_rdev = MKDEV(le64_to_cpu(info->DevMajor),
+                                       le64_to_cpu(info->DevMinor) & MINORMASK);
                 break;
         case UNIX_BLOCKDEV:
-                inode->i_mode |= S_IFBLK;
-                inode->i_rdev = MKDEV(le64_to_cpu(info->DevMajor),
-                                      le64_to_cpu(info->DevMinor) & MINORMASK);
+                fattr->cf_mode |= S_IFBLK;
+                fattr->cf_dtype = DT_BLK;
+                fattr->cf_rdev = MKDEV(le64_to_cpu(info->DevMajor),
+                                       le64_to_cpu(info->DevMinor) & MINORMASK);
                 break;
         case UNIX_FIFO:
-                inode->i_mode |= S_IFIFO;
+                fattr->cf_mode |= S_IFIFO;
+                fattr->cf_dtype = DT_FIFO;
                 break;
         case UNIX_SOCKET:
-                inode->i_mode |= S_IFSOCK;
+                fattr->cf_mode |= S_IFSOCK;
+                fattr->cf_dtype = DT_SOCK;
                 break;
         default:
                 /* safest to call it a file if we do not know */
-                inode->i_mode |= S_IFREG;
+                fattr->cf_mode |= S_IFREG;
+                fattr->cf_dtype = DT_REG;
                 cFYI(1, ("unknown type %d", le32_to_cpu(info->Type)));
                 break;
         }
 
-        if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID) &&
-            !force_uid_gid)
-                inode->i_uid = cifs_sb->mnt_uid;
+        if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID)
+                fattr->cf_uid = cifs_sb->mnt_uid;
         else
-                inode->i_uid = le64_to_cpu(info->Uid);
+                fattr->cf_uid = le64_to_cpu(info->Uid);
 
-        if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID) &&
-            !force_uid_gid)
-                inode->i_gid = cifs_sb->mnt_gid;
+        if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID)
+                fattr->cf_gid = cifs_sb->mnt_gid;
         else
-                inode->i_gid = le64_to_cpu(info->Gid);
+                fattr->cf_gid = le64_to_cpu(info->Gid);
 
-        inode->i_nlink = le64_to_cpu(info->Nlinks);
-
-        cifsInfo->server_eof = end_of_file;
-        spin_lock(&inode->i_lock);
-        if (is_size_safe_to_change(cifsInfo, end_of_file)) {
-                /*
-                 * We can not safely change the file size here if the client
-                 * is writing to it due to potential races.
-                 */
-                i_size_write(inode, end_of_file);
-
-                /*
-                 * i_blocks is not related to (i_size / i_blksize),
-                 * but instead 512 byte (2**9) size is required for
-                 * calculating num blocks.
-                 */
-                inode->i_blocks = (512 - 1 + num_of_bytes) >> 9;
-        }
-        spin_unlock(&inode->i_lock);
+        fattr->cf_nlink = le64_to_cpu(info->Nlinks);
 }
 
-
 /*
- *      Needed to setup inode data for the directory which is the
- *      junction to the new submount (ie to setup the fake directory
- *      which represents a DFS referral)
+ * Fill a cifs_fattr struct with fake inode info.
+ *
+ * Needed to setup cifs_fattr data for the directory which is the
+ * junction to the new submount (ie to setup the fake directory
+ * which represents a DFS referral).
  */
-static void fill_fake_finddataunix(FILE_UNIX_BASIC_INFO *pfnd_dat,
-                               struct super_block *sb)
+void
+cifs_create_dfs_fattr(struct cifs_fattr *fattr, struct super_block *sb)
 {
-        struct inode *pinode = NULL;
-
-        memset(pfnd_dat, 0, sizeof(FILE_UNIX_BASIC_INFO));
+        struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 
-/*      __le64 pfnd_dat->EndOfFile = cpu_to_le64(0);
-        __le64 pfnd_dat->NumOfBytes = cpu_to_le64(0);
-        __u64 UniqueId = 0;  */
-        pfnd_dat->LastStatusChange =
-                cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
-        pfnd_dat->LastAccessTime =
-                cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
-        pfnd_dat->LastModificationTime =
-                cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
-        pfnd_dat->Type = cpu_to_le32(UNIX_DIR);
-        pfnd_dat->Permissions = cpu_to_le64(S_IXUGO | S_IRWXU);
-        pfnd_dat->Nlinks = cpu_to_le64(2);
-        if (sb->s_root)
-                pinode = sb->s_root->d_inode;
-        if (pinode == NULL)
-                return;
-
-        /* fill in default values for the remaining based on root
-           inode since we can not query the server for this inode info */
-        pfnd_dat->DevMajor = cpu_to_le64(MAJOR(pinode->i_rdev));
-        pfnd_dat->DevMinor = cpu_to_le64(MINOR(pinode->i_rdev));
-        pfnd_dat->Uid = cpu_to_le64(pinode->i_uid);
-        pfnd_dat->Gid = cpu_to_le64(pinode->i_gid);
+        cFYI(1, ("creating fake fattr for DFS referral"));
+
+        memset(fattr, 0, sizeof(*fattr));
+        fattr->cf_mode = S_IFDIR | S_IXUGO | S_IRWXU;
+        fattr->cf_uid = cifs_sb->mnt_uid;
+        fattr->cf_gid = cifs_sb->mnt_gid;
+        fattr->cf_atime = CURRENT_TIME;
+        fattr->cf_ctime = CURRENT_TIME;
+        fattr->cf_mtime = CURRENT_TIME;
+        fattr->cf_nlink = 2;
+        fattr->cf_flags |= CIFS_FATTR_DFS_REFERRAL;
 }
 
 /**
@@ -244,66 +263,42 @@ cifs_new_inode(struct super_block *sb, __u64 *inum)
 }
 
 int cifs_get_inode_info_unix(struct inode **pinode,
-        const unsigned char *full_path, struct super_block *sb, int xid)
+                             const unsigned char *full_path,
+                             struct super_block *sb, int xid)
 {
-        int rc = 0;
+        int rc;
         FILE_UNIX_BASIC_INFO find_data;
-        struct cifsTconInfo *pTcon;
-        struct inode *inode;
+        struct cifs_fattr fattr;
+        struct cifsTconInfo *tcon;
         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
-        bool is_dfs_referral = false;
-        struct cifsInodeInfo *cifsInfo;
-        __u64 num_of_bytes;
-        __u64 end_of_file;
 
-        pTcon = cifs_sb->tcon;
+        tcon = cifs_sb->tcon;
         cFYI(1, ("Getting info on %s", full_path));
 
         /* could have done a find first instead but this returns more info */
-        rc = CIFSSMBUnixQPathInfo(xid, pTcon, full_path, &find_data,
+        rc = CIFSSMBUnixQPathInfo(xid, tcon, full_path, &find_data,
                                   cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
-        if (rc == -EREMOTE && !is_dfs_referral) {
-                is_dfs_referral = true;
-                cFYI(DBG2, ("DFS ref"));
-                /* for DFS, server does not give us real inode data */
-                fill_fake_finddataunix(&find_data, sb);
-                rc = 0;
-        } else if (rc)
-                goto cgiiu_exit;
 
-        num_of_bytes = le64_to_cpu(find_data.NumOfBytes);
-        end_of_file = le64_to_cpu(find_data.EndOfFile);
+        if (!rc) {
+                cifs_unix_basic_to_fattr(&fattr, &find_data, cifs_sb);
+        } else if (rc == -EREMOTE) {
+                cifs_create_dfs_fattr(&fattr, sb);
+                rc = 0;
+        } else {
+                return rc;
+        }
 
-        /* get new inode */
         if (*pinode == NULL) {
-                __u64 unique_id = le64_to_cpu(find_data.UniqueId);
-                *pinode = cifs_new_inode(sb, &unique_id);
-                if (*pinode == NULL) {
+                /* get new inode */
+                *pinode = cifs_iget(sb, &fattr);
+                if (!*pinode)
                         rc = -ENOMEM;
-                        goto cgiiu_exit;
-                }
+        } else {
+                /* we already have inode, update it */
+                cifs_fattr_to_inode(*pinode, &fattr);
         }
 
-        inode = *pinode;
-        cifsInfo = CIFS_I(inode);
-
-        cFYI(1, ("Old time %ld", cifsInfo->time));
-        cifsInfo->time = jiffies;
-        cFYI(1, ("New time %ld", cifsInfo->time));
-        /* this is ok to set on every inode revalidate */
-        atomic_set(&cifsInfo->inUse, 1);
-
-        cifs_unix_info_to_inode(inode, &find_data, 0);
-
-        if (num_of_bytes < end_of_file)
-                cFYI(1, ("allocation size less than end of file"));
-        cFYI(1, ("Size %ld and blocks %llu",
-                (unsigned long) inode->i_size,
-                (unsigned long long)inode->i_blocks));
-
-        cifs_set_ops(inode, is_dfs_referral);
-cgiiu_exit:
         return rc;
 }
 
@@ -695,33 +690,85 @@ char *cifs_build_path_to_root(struct cifs_sb_info *cifs_sb)
         return full_path;
 }
 
+static int
+cifs_find_inode(struct inode *inode, void *opaque)
+{
+        struct cifs_fattr *fattr = (struct cifs_fattr *) opaque;
+
+        if (CIFS_I(inode)->uniqueid != fattr->cf_uniqueid)
+                return 0;
+
+        return 1;
+}
+
+static int
+cifs_init_inode(struct inode *inode, void *opaque)
+{
+        struct cifs_fattr *fattr = (struct cifs_fattr *) opaque;
+
+        CIFS_I(inode)->uniqueid = fattr->cf_uniqueid;
+        return 0;
+}
+
+/* Given fattrs, get a corresponding inode */
+struct inode *
+cifs_iget(struct super_block *sb, struct cifs_fattr *fattr)
+{
+        unsigned long hash;
+        struct inode *inode;
+
+        cFYI(1, ("looking for uniqueid=%llu", fattr->cf_uniqueid));
+
+        /* hash down to 32-bits on 32-bit arch */
+        hash = cifs_uniqueid_to_ino_t(fattr->cf_uniqueid);
+
+        inode = iget5_locked(sb, hash, cifs_find_inode, cifs_init_inode, fattr);
+
+        /* we have fattrs in hand, update the inode */
+        if (inode) {
+                cifs_fattr_to_inode(inode, fattr);
+                if (sb->s_flags & MS_NOATIME)
+                        inode->i_flags |= S_NOATIME | S_NOCMTIME;
+                if (inode->i_state & I_NEW) {
+                        inode->i_ino = hash;
+                        unlock_new_inode(inode);
+                }
+        }
+
+        return inode;
+}
+
 /* gets root inode */
 struct inode *cifs_root_iget(struct super_block *sb, unsigned long ino)
 {
         int xid;
         struct cifs_sb_info *cifs_sb;
-        struct inode *inode;
+        struct inode *inode = NULL;
         long rc;
         char *full_path;
 
-        inode = iget_locked(sb, ino);
-        if (!inode)
-                return ERR_PTR(-ENOMEM);
-        if (!(inode->i_state & I_NEW))
-                return inode;
-
-        cifs_sb = CIFS_SB(inode->i_sb);
+        cifs_sb = CIFS_SB(sb);
         full_path = cifs_build_path_to_root(cifs_sb);
         if (full_path == NULL)
                 return ERR_PTR(-ENOMEM);
 
         xid = GetXid();
-        if (cifs_sb->tcon->unix_ext)
-                rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb,
-                                                xid);
-        else
+        if (cifs_sb->tcon->unix_ext) {
+                rc = cifs_get_inode_info_unix(&inode, full_path, sb, xid);
+                if (!inode)
+                        return ERR_PTR(-ENOMEM);
+        } else {
+                inode = iget_locked(sb, ino);
+                if (!inode)
+                        return ERR_PTR(-ENOMEM);
+                if (!(inode->i_state & I_NEW))
+                        return inode;
+
                 rc = cifs_get_inode_info(&inode, full_path, NULL, inode->i_sb,
                                                 xid, NULL);
+                unlock_new_inode(inode);
+        }
+
         if (rc && cifs_sb->tcon->ipc) {
                 cFYI(1, ("ipc connection - fake read inode"));
                 inode->i_mode |= S_IFDIR;
@@ -737,7 +784,6 @@ struct inode *cifs_root_iget(struct super_block *sb, unsigned long ino)
                 return ERR_PTR(rc);
         }
 
-        unlock_new_inode(inode);
 
         kfree(full_path);
         /* can not call macro FreeXid here since in a void func
@@ -1063,44 +1109,6 @@ out_reval:
         return rc;
 }
 
-void posix_fill_in_inode(struct inode *tmp_inode,
-        FILE_UNIX_BASIC_INFO *pData, int isNewInode)
-{
-        struct cifsInodeInfo *cifsInfo = CIFS_I(tmp_inode);
-        loff_t local_size;
-        struct timespec local_mtime;
-
-        cifsInfo->time = jiffies;
-        atomic_inc(&cifsInfo->inUse);
-
-        /* save mtime and size */
-        local_mtime = tmp_inode->i_mtime;
-        local_size  = tmp_inode->i_size;
-
-        cifs_unix_info_to_inode(tmp_inode, pData, 1);
-        cifs_set_ops(tmp_inode, false);
-
-        if (!S_ISREG(tmp_inode->i_mode))
-                return;
-
-        /*
-         * No sense invalidating pages for new inode
-         * since we we have not started caching
-         * readahead file data yet.
-         */
-        if (isNewInode)
-                return;
-
-        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);
-        }
-}
-
 int cifs_mkdir(struct inode *inode, struct dentry *direntry, int mode)
 {
         int rc = 0, tmprc;
@@ -1109,6 +1117,7 @@ int cifs_mkdir(struct inode *inode, struct dentry *direntry, int mode)
         struct cifsTconInfo *pTcon;
         char *full_path = NULL;
         struct inode *newinode = NULL;
+        struct cifs_fattr fattr;
 
         cFYI(1, ("In cifs_mkdir, mode = 0x%x inode = 0x%p", mode, inode));
 
@@ -1148,7 +1157,6 @@ int cifs_mkdir(struct inode *inode, struct dentry *direntry, int mode)
                         cFYI(1, ("posix mkdir returned 0x%x", rc));
                         d_drop(direntry);
                 } else {
-                        __u64 unique_id;
                         if (pInfo->Type == cpu_to_le32(-1)) {
                                 /* no return info, go query for it */
                                 kfree(pInfo);
@@ -1162,20 +1170,15 @@ int cifs_mkdir(struct inode *inode, struct dentry *direntry, int mode)
                         else
                                 direntry->d_op = &cifs_dentry_ops;
 
-                        unique_id = le64_to_cpu(pInfo->UniqueId);
-                        newinode = cifs_new_inode(inode->i_sb, &unique_id);
-                        if (newinode == NULL) {
+                        cifs_unix_basic_to_fattr(&fattr, pInfo, cifs_sb);
+                        newinode = cifs_iget(inode->i_sb, &fattr);
+                        if (!newinode) {
                                 kfree(pInfo);
                                 goto mkdir_get_info;
                         }
 
-                        newinode->i_nlink = 2;
                         d_instantiate(direntry, newinode);
 
-                        /* we already checked in POSIXCreate whether
-                           frame was long enough */
-                        posix_fill_in_inode(direntry->d_inode,
-                                        pInfo, 1 /* NewInode */);
 #ifdef CONFIG_CIFS_DEBUG2
                         cFYI(1, ("instantiated dentry %p %s to inode %p",
                                 direntry, direntry->d_name.name, newinode));
@@ -1622,6 +1625,7 @@ int cifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
         if (!err) {
                 generic_fillattr(dentry->d_inode, stat);
                 stat->blksize = CIFS_MAX_MSGSIZE;
+                stat->ino = CIFS_I(dentry->d_inode)->uniqueid;
         }
         return err;
 }