~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/xfs/xfs_export.c

Version: ~ [ linux-5.16-rc3 ] ~ [ linux-5.15.5 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.82 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.162 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.218 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.256 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.291 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.293 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  * Copyright (c) 2004-2005 Silicon Graphics, Inc.
  4  * All Rights Reserved.
  5  */
  6 #include "xfs.h"
  7 #include "xfs_shared.h"
  8 #include "xfs_format.h"
  9 #include "xfs_log_format.h"
 10 #include "xfs_trans_resv.h"
 11 #include "xfs_mount.h"
 12 #include "xfs_dir2.h"
 13 #include "xfs_export.h"
 14 #include "xfs_inode.h"
 15 #include "xfs_trans.h"
 16 #include "xfs_inode_item.h"
 17 #include "xfs_icache.h"
 18 #include "xfs_pnfs.h"
 19 
 20 /*
 21  * Note that we only accept fileids which are long enough rather than allow
 22  * the parent generation number to default to zero.  XFS considers zero a
 23  * valid generation number not an invalid/wildcard value.
 24  */
 25 static int xfs_fileid_length(int fileid_type)
 26 {
 27         switch (fileid_type) {
 28         case FILEID_INO32_GEN:
 29                 return 2;
 30         case FILEID_INO32_GEN_PARENT:
 31                 return 4;
 32         case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
 33                 return 3;
 34         case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
 35                 return 6;
 36         }
 37         return FILEID_INVALID;
 38 }
 39 
 40 STATIC int
 41 xfs_fs_encode_fh(
 42         struct inode    *inode,
 43         __u32           *fh,
 44         int             *max_len,
 45         struct inode    *parent)
 46 {
 47         struct fid              *fid = (struct fid *)fh;
 48         struct xfs_fid64        *fid64 = (struct xfs_fid64 *)fh;
 49         int                     fileid_type;
 50         int                     len;
 51 
 52         /* Directories don't need their parent encoded, they have ".." */
 53         if (!parent)
 54                 fileid_type = FILEID_INO32_GEN;
 55         else
 56                 fileid_type = FILEID_INO32_GEN_PARENT;
 57 
 58         /*
 59          * If the filesystem may contain 64bit inode numbers, we need
 60          * to use larger file handles that can represent them.
 61          *
 62          * While we only allocate inodes that do not fit into 32 bits any
 63          * large enough filesystem may contain them, thus the slightly
 64          * confusing looking conditional below.
 65          */
 66         if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS) ||
 67             (XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_32BITINODES))
 68                 fileid_type |= XFS_FILEID_TYPE_64FLAG;
 69 
 70         /*
 71          * Only encode if there is enough space given.  In practice
 72          * this means we can't export a filesystem with 64bit inodes
 73          * over NFSv2 with the subtree_check export option; the other
 74          * seven combinations work.  The real answer is "don't use v2".
 75          */
 76         len = xfs_fileid_length(fileid_type);
 77         if (*max_len < len) {
 78                 *max_len = len;
 79                 return FILEID_INVALID;
 80         }
 81         *max_len = len;
 82 
 83         switch (fileid_type) {
 84         case FILEID_INO32_GEN_PARENT:
 85                 fid->i32.parent_ino = XFS_I(parent)->i_ino;
 86                 fid->i32.parent_gen = parent->i_generation;
 87                 /*FALLTHRU*/
 88         case FILEID_INO32_GEN:
 89                 fid->i32.ino = XFS_I(inode)->i_ino;
 90                 fid->i32.gen = inode->i_generation;
 91                 break;
 92         case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
 93                 fid64->parent_ino = XFS_I(parent)->i_ino;
 94                 fid64->parent_gen = parent->i_generation;
 95                 /*FALLTHRU*/
 96         case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
 97                 fid64->ino = XFS_I(inode)->i_ino;
 98                 fid64->gen = inode->i_generation;
 99                 break;
100         }
101 
102         return fileid_type;
103 }
104 
105 STATIC struct inode *
106 xfs_nfs_get_inode(
107         struct super_block      *sb,
108         u64                     ino,
109         u32                     generation)
110 {
111         xfs_mount_t             *mp = XFS_M(sb);
112         xfs_inode_t             *ip;
113         int                     error;
114 
115         /*
116          * NFS can sometimes send requests for ino 0.  Fail them gracefully.
117          */
118         if (ino == 0)
119                 return ERR_PTR(-ESTALE);
120 
121         /*
122          * The XFS_IGET_UNTRUSTED means that an invalid inode number is just
123          * fine and not an indication of a corrupted filesystem as clients can
124          * send invalid file handles and we have to handle it gracefully..
125          */
126         error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
127         if (error) {
128 
129                 /*
130                  * EINVAL means the inode cluster doesn't exist anymore.
131                  * EFSCORRUPTED means the metadata pointing to the inode cluster
132                  * or the inode cluster itself is corrupt.  This implies the
133                  * filehandle is stale, so we should translate it here.
134                  * We don't use ESTALE directly down the chain to not
135                  * confuse applications using bulkstat that expect EINVAL.
136                  */
137                 switch (error) {
138                 case -EINVAL:
139                 case -ENOENT:
140                 case -EFSCORRUPTED:
141                         error = -ESTALE;
142                         break;
143                 default:
144                         break;
145                 }
146                 return ERR_PTR(error);
147         }
148 
149         if (VFS_I(ip)->i_generation != generation) {
150                 xfs_irele(ip);
151                 return ERR_PTR(-ESTALE);
152         }
153 
154         return VFS_I(ip);
155 }
156 
157 STATIC struct dentry *
158 xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
159                  int fh_len, int fileid_type)
160 {
161         struct xfs_fid64        *fid64 = (struct xfs_fid64 *)fid;
162         struct inode            *inode = NULL;
163 
164         if (fh_len < xfs_fileid_length(fileid_type))
165                 return NULL;
166 
167         switch (fileid_type) {
168         case FILEID_INO32_GEN_PARENT:
169         case FILEID_INO32_GEN:
170                 inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
171                 break;
172         case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
173         case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
174                 inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
175                 break;
176         }
177 
178         return d_obtain_alias(inode);
179 }
180 
181 STATIC struct dentry *
182 xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
183                  int fh_len, int fileid_type)
184 {
185         struct xfs_fid64        *fid64 = (struct xfs_fid64 *)fid;
186         struct inode            *inode = NULL;
187 
188         if (fh_len < xfs_fileid_length(fileid_type))
189                 return NULL;
190 
191         switch (fileid_type) {
192         case FILEID_INO32_GEN_PARENT:
193                 inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
194                                               fid->i32.parent_gen);
195                 break;
196         case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
197                 inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
198                                               fid64->parent_gen);
199                 break;
200         }
201 
202         return d_obtain_alias(inode);
203 }
204 
205 STATIC struct dentry *
206 xfs_fs_get_parent(
207         struct dentry           *child)
208 {
209         int                     error;
210         struct xfs_inode        *cip;
211 
212         error = xfs_lookup(XFS_I(d_inode(child)), &xfs_name_dotdot, &cip, NULL);
213         if (unlikely(error))
214                 return ERR_PTR(error);
215 
216         return d_obtain_alias(VFS_I(cip));
217 }
218 
219 STATIC int
220 xfs_fs_nfs_commit_metadata(
221         struct inode            *inode)
222 {
223         return xfs_log_force_inode(XFS_I(inode));
224 }
225 
226 const struct export_operations xfs_export_operations = {
227         .encode_fh              = xfs_fs_encode_fh,
228         .fh_to_dentry           = xfs_fs_fh_to_dentry,
229         .fh_to_parent           = xfs_fs_fh_to_parent,
230         .get_parent             = xfs_fs_get_parent,
231         .commit_metadata        = xfs_fs_nfs_commit_metadata,
232 #ifdef CONFIG_EXPORTFS_BLOCK_OPS
233         .get_uuid               = xfs_fs_get_uuid,
234         .map_blocks             = xfs_fs_map_blocks,
235         .commit_blocks          = xfs_fs_commit_blocks,
236 #endif
237 };
238 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp