[GFS2] Fix unlinked file handling

This patch fixes the way we have been dealing with unlinked,
but still open files. It removes all limits (other than memory
for inodes, as per every other filesystem) on numbers of these
which we can support on GFS2. It also means that (like other
fs) its the responsibility of the last process to close the file
to deallocate the storage, rather than the person who did the
unlinking. Note that with GFS2, those two events might take place
on different nodes.

Also there are a number of other changes:

 o We use the Linux inode subsystem as it was intended to be
used, wrt allocating GFS2 inodes
 o The Linux inode cache is now the point which we use for
local enforcement of only holding one copy of the inode in
core at once (previous to this we used the glock layer).
 o We no longer use the unlinked "special" file. We just ignore it
completely. This makes unlinking more efficient.
 o We now use the 4th block allocation state. The previously unused
state is used to track unlinked but still open inodes.
 o gfs2_inoded is no longer needed
 o Several fields are now no longer needed (and removed) from the in
core struct gfs2_inode
 o Several fields are no longer needed (and removed) from the in core
superblock

There are a number of future possible optimisations and clean ups
which have been made possible by this patch.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 70 insertions, 98 deletions

diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index 0c06f92368f2..f678f6b62afd 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -38,7 +38,6 @@
 #include "quota.h"
 #include "rgrp.h"
 #include "trans.h"
-#include "unlinked.h"
 #include "util.h"
 
 /**
@@ -53,8 +52,8 @@
 static int gfs2_create(struct inode *dir, struct dentry *dentry,
                        int mode, struct nameidata *nd)
 {
-        struct gfs2_inode *dip = dir->u.generic_ip;
-        struct gfs2_sbd *sdp = dip->i_sbd;
+        struct gfs2_inode *dip = GFS2_I(dir);
+        struct gfs2_sbd *sdp = GFS2_SB(dir);
         struct gfs2_holder ghs[2];
         struct inode *inode;
         int new = 1;
@@ -141,10 +140,10 @@ static struct dentry *gfs2_lookup(struct inode *dir, struct dentry *dentry,
 static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
                      struct dentry *dentry)
 {
-        struct gfs2_inode *dip = dir->u.generic_ip;
-        struct gfs2_sbd *sdp = dip->i_sbd;
+        struct gfs2_inode *dip = GFS2_I(dir);
+        struct gfs2_sbd *sdp = GFS2_SB(dir);
         struct inode *inode = old_dentry->d_inode;
-        struct gfs2_inode *ip = inode->u.generic_ip;
+        struct gfs2_inode *ip = GFS2_I(inode);
         struct gfs2_holder ghs[2];
         int alloc_required;
         int error;
@@ -231,30 +230,29 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
 
         error = gfs2_change_nlink(ip, +1);
 
- out_end_trans:
+out_end_trans:
         gfs2_trans_end(sdp);
 
- out_ipres:
+out_ipres:
         if (alloc_required)
                 gfs2_inplace_release(dip);
 
- out_gunlock_q:
+out_gunlock_q:
         if (alloc_required)
                 gfs2_quota_unlock(dip);
 
- out_alloc:
+out_alloc:
         if (alloc_required)
                 gfs2_alloc_put(dip);
 
- out_gunlock:
+out_gunlock:
         gfs2_glock_dq_m(2, ghs);
 
- out:
+out:
         gfs2_holder_uninit(ghs);
         gfs2_holder_uninit(ghs + 1);
 
         if (!error) {
-                atomic_inc(&inode->i_count);
                 d_instantiate(dentry, inode);
                 mark_inode_dirty(inode);
         }
@@ -274,17 +272,12 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
 
 static int gfs2_unlink(struct inode *dir, struct dentry *dentry)
 {
-        struct gfs2_inode *dip = dir->u.generic_ip;
-        struct gfs2_sbd *sdp = dip->i_sbd;
-        struct gfs2_inode *ip = dentry->d_inode->u.generic_ip;
-        struct gfs2_unlinked *ul;
+        struct gfs2_inode *dip = GFS2_I(dir);
+        struct gfs2_sbd *sdp = GFS2_SB(dir);
+        struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
         struct gfs2_holder ghs[2];
         int error;
 
-        error = gfs2_unlinked_get(sdp, &ul);
-        if (error)
-                return error;
-
         gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
         gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);
 
@@ -296,24 +289,23 @@ static int gfs2_unlink(struct inode *dir, struct dentry *dentry)
         if (error)
                 goto out_gunlock;
 
-        error = gfs2_trans_begin(sdp, 2 * RES_DINODE + RES_LEAF +
-                                RES_UNLINKED, 0);
+        error = gfs2_trans_begin(sdp, 2*RES_DINODE + RES_LEAF + RES_RG_BIT, 0);
         if (error)
                 goto out_gunlock;
 
-        error = gfs2_unlinki(dip, &dentry->d_name, ip, ul);
+        error = gfs2_dir_del(dip, &dentry->d_name);
+        if (error)
+                goto out_end_trans;
 
-        gfs2_trans_end(sdp);
+        error = gfs2_change_nlink(ip, -1);
 
- out_gunlock:
+out_end_trans:
+        gfs2_trans_end(sdp);
+out_gunlock:
         gfs2_glock_dq_m(2, ghs);
-
- out:
+out:
         gfs2_holder_uninit(ghs);
         gfs2_holder_uninit(ghs + 1);
-
-        gfs2_unlinked_put(sdp, ul);
-
         return error;
 }
 
@@ -329,8 +321,8 @@ static int gfs2_unlink(struct inode *dir, struct dentry *dentry)
 static int gfs2_symlink(struct inode *dir, struct dentry *dentry,
                         const char *symname)
 {
-        struct gfs2_inode *dip = dir->u.generic_ip, *ip;
-        struct gfs2_sbd *sdp = dip->i_sbd;
+        struct gfs2_inode *dip = GFS2_I(dir), *ip;
+        struct gfs2_sbd *sdp = GFS2_SB(dir);
         struct gfs2_holder ghs[2];
         struct inode *inode;
         struct buffer_head *dibh;
@@ -388,8 +380,8 @@ static int gfs2_symlink(struct inode *dir, struct dentry *dentry,
 
 static int gfs2_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 {
-        struct gfs2_inode *dip = dir->u.generic_ip, *ip;
-        struct gfs2_sbd *sdp = dip->i_sbd;
+        struct gfs2_inode *dip = GFS2_I(dir), *ip;
+        struct gfs2_sbd *sdp = GFS2_SB(dir);
         struct gfs2_holder ghs[2];
         struct inode *inode;
         struct buffer_head *dibh;
@@ -466,17 +458,12 @@ static int gfs2_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 
 static int gfs2_rmdir(struct inode *dir, struct dentry *dentry)
 {
-        struct gfs2_inode *dip = dir->u.generic_ip;
-        struct gfs2_sbd *sdp = dip->i_sbd;
-        struct gfs2_inode *ip = dentry->d_inode->u.generic_ip;
-        struct gfs2_unlinked *ul;
+        struct gfs2_inode *dip = GFS2_I(dir);
+        struct gfs2_sbd *sdp = GFS2_SB(dir);
+        struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
         struct gfs2_holder ghs[2];
         int error;
 
-        error = gfs2_unlinked_get(sdp, &ul);
-        if (error)
-                return error;
-
         gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
         gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);
 
@@ -499,12 +486,11 @@ static int gfs2_rmdir(struct inode *dir, struct dentry *dentry)
                 goto out_gunlock;
         }
 
-        error = gfs2_trans_begin(sdp, 2 * RES_DINODE + 3 * RES_LEAF +
-                                RES_UNLINKED, 0);
+        error = gfs2_trans_begin(sdp, 2 * RES_DINODE + 3 * RES_LEAF + RES_RG_BIT, 0);
         if (error)
                 goto out_gunlock;
 
-        error = gfs2_rmdiri(dip, &dentry->d_name, ip, ul);
+        error = gfs2_rmdiri(dip, &dentry->d_name, ip);
 
         gfs2_trans_end(sdp);
 
@@ -515,8 +501,6 @@ static int gfs2_rmdir(struct inode *dir, struct dentry *dentry)
         gfs2_holder_uninit(ghs);
         gfs2_holder_uninit(ghs + 1);
 
-        gfs2_unlinked_put(sdp, ul);
-
         return error;
 }
 
@@ -532,8 +516,8 @@ static int gfs2_rmdir(struct inode *dir, struct dentry *dentry)
 static int gfs2_mknod(struct inode *dir, struct dentry *dentry, int mode,
                       dev_t dev)
 {
-        struct gfs2_inode *dip = dir->u.generic_ip, *ip;
-        struct gfs2_sbd *sdp = dip->i_sbd;
+        struct gfs2_inode *dip = GFS2_I(dir), *ip;
+        struct gfs2_sbd *sdp = GFS2_SB(dir);
         struct gfs2_holder ghs[2];
         struct inode *inode;
         struct buffer_head *dibh;
@@ -600,12 +584,11 @@ static int gfs2_mknod(struct inode *dir, struct dentry *dentry, int mode,
 static int gfs2_rename(struct inode *odir, struct dentry *odentry,
                        struct inode *ndir, struct dentry *ndentry)
 {
-        struct gfs2_inode *odip = odir->u.generic_ip;
-        struct gfs2_inode *ndip = ndir->u.generic_ip;
-        struct gfs2_inode *ip = odentry->d_inode->u.generic_ip;
+        struct gfs2_inode *odip = GFS2_I(odir);
+        struct gfs2_inode *ndip = GFS2_I(ndir);
+        struct gfs2_inode *ip = GFS2_I(odentry->d_inode);
         struct gfs2_inode *nip = NULL;
-        struct gfs2_sbd *sdp = odip->i_sbd;
-        struct gfs2_unlinked *ul;
+        struct gfs2_sbd *sdp = GFS2_SB(odir);
         struct gfs2_holder ghs[4], r_gh;
         unsigned int num_gh;
         int dir_rename = 0;
@@ -614,15 +597,11 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
         int error;
 
         if (ndentry->d_inode) {
-                nip = ndentry->d_inode->u.generic_ip;
+                nip = GFS2_I(ndentry->d_inode);
                 if (ip == nip)
                         return 0;
         }
 
-        error = gfs2_unlinked_get(sdp, &ul);
-        if (error)
-                return error;
-
         /* Make sure we aren't trying to move a dirctory into it's subdir */
 
         if (S_ISDIR(ip->i_di.di_mode) && odip != ndip) {
@@ -743,14 +722,12 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
                 error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +
                                          al->al_rgd->rd_ri.ri_length +
                                          4 * RES_DINODE + 4 * RES_LEAF +
-                                         RES_UNLINKED + RES_STATFS +
-                                         RES_QUOTA, 0);
+                                         RES_STATFS + RES_QUOTA, 0);
                 if (error)
                         goto out_ipreserv;
         } else {
                 error = gfs2_trans_begin(sdp, 4 * RES_DINODE +
-                                         5 * RES_LEAF +
-                                         RES_UNLINKED, 0);
+                                         5 * RES_LEAF, 0);
                 if (error)
                         goto out_gunlock;
         }
@@ -759,9 +736,13 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
 
         if (nip) {
                 if (S_ISDIR(nip->i_di.di_mode))
-                        error = gfs2_rmdiri(ndip, &ndentry->d_name, nip, ul);
-                else
-                        error = gfs2_unlinki(ndip, &ndentry->d_name, nip, ul);
+                        error = gfs2_rmdiri(ndip, &ndentry->d_name, nip);
+                else {
+                        error = gfs2_dir_del(ndip, &ndentry->d_name);
+                        if (error)
+                                goto out_end_trans;
+                        error = gfs2_change_nlink(nip, -1);
+                }
                 if (error)
                         goto out_end_trans;
         }
@@ -800,35 +781,26 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
         if (error)
                 goto out_end_trans;
 
- out_end_trans:
+out_end_trans:
         gfs2_trans_end(sdp);
-
- out_ipreserv:
+out_ipreserv:
         if (alloc_required)
                 gfs2_inplace_release(ndip);
-
- out_gunlock_q:
+out_gunlock_q:
         if (alloc_required)
                 gfs2_quota_unlock(ndip);
-
- out_alloc:
+out_alloc:
         if (alloc_required)
                 gfs2_alloc_put(ndip);
-
- out_gunlock:
+out_gunlock:
         gfs2_glock_dq_m(num_gh, ghs);
-
- out_uninit:
+out_uninit:
         for (x = 0; x < num_gh; x++)
                 gfs2_holder_uninit(ghs + x);
-
- out_gunlock_r:
+out_gunlock_r:
         if (dir_rename)
                 gfs2_glock_dq_uninit(&r_gh);
-
- out:
-        gfs2_unlinked_put(sdp, ul);
-
+out:
         return error;
 }
 
@@ -844,7 +816,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
 static int gfs2_readlink(struct dentry *dentry, char __user *user_buf,
                          int user_size)
 {
-        struct gfs2_inode *ip = dentry->d_inode->u.generic_ip;
+        struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
         char array[GFS2_FAST_NAME_SIZE], *buf = array;
         unsigned int len = GFS2_FAST_NAME_SIZE;
         int error;
@@ -880,7 +852,7 @@ static int gfs2_readlink(struct dentry *dentry, char __user *user_buf,
 
 static void *gfs2_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
-        struct gfs2_inode *ip = dentry->d_inode->u.generic_ip;
+        struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
         char array[GFS2_FAST_NAME_SIZE], *buf = array;
         unsigned int len = GFS2_FAST_NAME_SIZE;
         int error;
@@ -906,7 +878,7 @@ static void *gfs2_follow_link(struct dentry *dentry, struct nameidata *nd)
 
 static int gfs2_permission(struct inode *inode, int mask, struct nameidata *nd)
 {
-        struct gfs2_inode *ip = inode->u.generic_ip;
+        struct gfs2_inode *ip = GFS2_I(inode);
         struct gfs2_holder i_gh;
         int error;
 
@@ -926,7 +898,7 @@ static int gfs2_permission(struct inode *inode, int mask, struct nameidata *nd)
 
 static int setattr_size(struct inode *inode, struct iattr *attr)
 {
-        struct gfs2_inode *ip = inode->u.generic_ip;
+        struct gfs2_inode *ip = GFS2_I(inode);
         int error;
 
         if (attr->ia_size != ip->i_di.di_size) {
@@ -944,8 +916,8 @@ static int setattr_size(struct inode *inode, struct iattr *attr)
 
 static int setattr_chown(struct inode *inode, struct iattr *attr)
 {
-        struct gfs2_inode *ip = inode->u.generic_ip;
-        struct gfs2_sbd *sdp = ip->i_sbd;
+        struct gfs2_inode *ip = GFS2_I(inode);
+        struct gfs2_sbd *sdp = GFS2_SB(inode);
         struct buffer_head *dibh;
         uint32_t ouid, ogid, nuid, ngid;
         int error;
@@ -1021,7 +993,7 @@ static int setattr_chown(struct inode *inode, struct iattr *attr)
 static int gfs2_setattr(struct dentry *dentry, struct iattr *attr)
 {
         struct inode *inode = dentry->d_inode;
-        struct gfs2_inode *ip = inode->u.generic_ip;
+        struct gfs2_inode *ip = GFS2_I(inode);
         struct gfs2_holder i_gh;
         int error;
 
@@ -1068,7 +1040,7 @@ static int gfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
                         struct kstat *stat)
 {
         struct inode *inode = dentry->d_inode;
-        struct gfs2_inode *ip = inode->u.generic_ip;
+        struct gfs2_inode *ip = GFS2_I(inode);
         struct gfs2_holder gh;
         int error;
 
@@ -1084,7 +1056,7 @@ static int gfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
 static int gfs2_setxattr(struct dentry *dentry, const char *name,
                          const void *data, size_t size, int flags)
 {
-        struct gfs2_inode *ip = dentry->d_inode->u.generic_ip;
+        struct inode *inode = dentry->d_inode;
         struct gfs2_ea_request er;
 
         memset(&er, 0, sizeof(struct gfs2_ea_request));
@@ -1096,9 +1068,9 @@ static int gfs2_setxattr(struct dentry *dentry, const char *name,
         er.er_data_len = size;
         er.er_flags = flags;
 
-        gfs2_assert_warn(ip->i_sbd, !(er.er_flags & GFS2_ERF_MODE));
+        gfs2_assert_warn(GFS2_SB(inode), !(er.er_flags & GFS2_ERF_MODE));
 
-        return gfs2_ea_set(ip, &er);
+        return gfs2_ea_set(GFS2_I(inode), &er);
 }
 
 static ssize_t gfs2_getxattr(struct dentry *dentry, const char *name,
@@ -1114,7 +1086,7 @@ static ssize_t gfs2_getxattr(struct dentry *dentry, const char *name,
         er.er_name_len = strlen(er.er_name);
         er.er_data_len = size;
 
-        return gfs2_ea_get(dentry->d_inode->u.generic_ip, &er);
+        return gfs2_ea_get(GFS2_I(dentry->d_inode), &er);
 }
 
 static ssize_t gfs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
@@ -1125,7 +1097,7 @@ static ssize_t gfs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
         er.er_data = (size) ? buffer : NULL;
         er.er_data_len = size;
 
-        return gfs2_ea_list(dentry->d_inode->u.generic_ip, &er);
+        return gfs2_ea_list(GFS2_I(dentry->d_inode), &er);
 }
 
 static int gfs2_removexattr(struct dentry *dentry, const char *name)
@@ -1138,7 +1110,7 @@ static int gfs2_removexattr(struct dentry *dentry, const char *name)
                 return -EOPNOTSUPP;
         er.er_name_len = strlen(er.er_name);
 
-        return gfs2_ea_remove(dentry->d_inode->u.generic_ip, &er);
+        return gfs2_ea_remove(GFS2_I(dentry->d_inode), &er);
 }
 
 struct inode_operations gfs2_file_iops = {