fs/jfs/xattr.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
is_known_namespace
name_size
copy_name
ea_write_inline
ea_write
ea_read_inline
ea_read
ea_get
ea_release
ea_put
__jfs_setxattr
__jfs_getxattr
can_list
jfs_listxattr
__jfs_xattr_set
jfs_xattr_get
jfs_xattr_set
jfs_xattr_get_os2
jfs_xattr_set_os2
jfs_initxattrs
jfs_init_security
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *   Copyright (C) International Business Machines  Corp., 2000-2004
   4  *   Copyright (C) Christoph Hellwig, 2002
   5  */
   6 
   7 #include <linux/capability.h>
   8 #include <linux/fs.h>
   9 #include <linux/xattr.h>
  10 #include <linux/posix_acl_xattr.h>
  11 #include <linux/slab.h>
  12 #include <linux/quotaops.h>
  13 #include <linux/security.h>
  14 #include "jfs_incore.h"
  15 #include "jfs_superblock.h"
  16 #include "jfs_dmap.h"
  17 #include "jfs_debug.h"
  18 #include "jfs_dinode.h"
  19 #include "jfs_extent.h"
  20 #include "jfs_metapage.h"
  21 #include "jfs_xattr.h"
  22 #include "jfs_acl.h"
  23 
  24 /*
  25  *      jfs_xattr.c: extended attribute service
  26  *
  27  * Overall design --
  28  *
  29  * Format:
  30  *
  31  *   Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit
  32  *   value) and a variable (0 or more) number of extended attribute
  33  *   entries.  Each extended attribute entry (jfs_ea) is a <name,value> double
  34  *   where <name> is constructed from a null-terminated ascii string
  35  *   (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data
  36  *   (1 ... 65535 bytes).  The in-memory format is
  37  *
  38  *   0       1        2        4                4 + namelen + 1
  39  *   +-------+--------+--------+----------------+-------------------+
  40  *   | Flags | Name   | Value  | Name String \0 | Data . . . .      |
  41  *   |       | Length | Length |                |                   |
  42  *   +-------+--------+--------+----------------+-------------------+
  43  *
  44  *   A jfs_ea_list then is structured as
  45  *
  46  *   0            4                   4 + EA_SIZE(ea1)
  47  *   +------------+-------------------+--------------------+-----
  48  *   | Overall EA | First FEA Element | Second FEA Element | .....
  49  *   | List Size  |                   |                    |
  50  *   +------------+-------------------+--------------------+-----
  51  *
  52  *   On-disk:
  53  *
  54  *      FEALISTs are stored on disk using blocks allocated by dbAlloc() and
  55  *      written directly. An EA list may be in-lined in the inode if there is
  56  *      sufficient room available.
  57  */
  58 
  59 struct ea_buffer {
  60         int flag;               /* Indicates what storage xattr points to */
  61         int max_size;           /* largest xattr that fits in current buffer */
  62         dxd_t new_ea;           /* dxd to replace ea when modifying xattr */
  63         struct metapage *mp;    /* metapage containing ea list */
  64         struct jfs_ea_list *xattr;      /* buffer containing ea list */
  65 };
  66 
  67 /*
  68  * ea_buffer.flag values
  69  */
  70 #define EA_INLINE       0x0001
  71 #define EA_EXTENT       0x0002
  72 #define EA_NEW          0x0004
  73 #define EA_MALLOC       0x0008
  74 
  75 
  76 /*
  77  * Mapping of on-disk attribute names: for on-disk attribute names with an
  78  * unknown prefix (not "system.", "user.", "security.", or "trusted."), the
  79  * prefix "os2." is prepended.  On the way back to disk, "os2." prefixes are
  80  * stripped and we make sure that the remaining name does not start with one
  81  * of the know prefixes.
  82  */
  83 
  84 static int is_known_namespace(const char *name)
  85 {
  86         if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
  87             strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
  88             strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
  89             strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
  90                 return false;
  91 
  92         return true;
  93 }
  94 
  95 static inline int name_size(struct jfs_ea *ea)
  96 {
  97         if (is_known_namespace(ea->name))
  98                 return ea->namelen;
  99         else
 100                 return ea->namelen + XATTR_OS2_PREFIX_LEN;
 101 }
 102 
 103 static inline int copy_name(char *buffer, struct jfs_ea *ea)
 104 {
 105         int len = ea->namelen;
 106 
 107         if (!is_known_namespace(ea->name)) {
 108                 memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
 109                 buffer += XATTR_OS2_PREFIX_LEN;
 110                 len += XATTR_OS2_PREFIX_LEN;
 111         }
 112         memcpy(buffer, ea->name, ea->namelen);
 113         buffer[ea->namelen] = 0;
 114 
 115         return len;
 116 }
 117 
 118 /* Forward references */
 119 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf);
 120 
 121 /*
 122  * NAME: ea_write_inline
 123  *
 124  * FUNCTION: Attempt to write an EA inline if area is available
 125  *
 126  * PRE CONDITIONS:
 127  *      Already verified that the specified EA is small enough to fit inline
 128  *
 129  * PARAMETERS:
 130  *      ip      - Inode pointer
 131  *      ealist  - EA list pointer
 132  *      size    - size of ealist in bytes
 133  *      ea      - dxd_t structure to be filled in with necessary EA information
 134  *                if we successfully copy the EA inline
 135  *
 136  * NOTES:
 137  *      Checks if the inode's inline area is available.  If so, copies EA inline
 138  *      and sets <ea> fields appropriately.  Otherwise, returns failure, EA will
 139  *      have to be put into an extent.
 140  *
 141  * RETURNS: 0 for successful copy to inline area; -1 if area not available
 142  */
 143 static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist,
 144                            int size, dxd_t * ea)
 145 {
 146         struct jfs_inode_info *ji = JFS_IP(ip);
 147 
 148         /*
 149          * Make sure we have an EA -- the NULL EA list is valid, but you
 150          * can't copy it!
 151          */
 152         if (ealist && size > sizeof (struct jfs_ea_list)) {
 153                 assert(size <= sizeof (ji->i_inline_ea));
 154 
 155                 /*
 156                  * See if the space is available or if it is already being
 157                  * used for an inline EA.
 158                  */
 159                 if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE))
 160                         return -EPERM;
 161 
 162                 DXDsize(ea, size);
 163                 DXDlength(ea, 0);
 164                 DXDaddress(ea, 0);
 165                 memcpy(ji->i_inline_ea, ealist, size);
 166                 ea->flag = DXD_INLINE;
 167                 ji->mode2 &= ~INLINEEA;
 168         } else {
 169                 ea->flag = 0;
 170                 DXDsize(ea, 0);
 171                 DXDlength(ea, 0);
 172                 DXDaddress(ea, 0);
 173 
 174                 /* Free up INLINE area */
 175                 if (ji->ea.flag & DXD_INLINE)
 176                         ji->mode2 |= INLINEEA;
 177         }
 178 
 179         return 0;
 180 }
 181 
 182 /*
 183  * NAME: ea_write
 184  *
 185  * FUNCTION: Write an EA for an inode
 186  *
 187  * PRE CONDITIONS: EA has been verified
 188  *
 189  * PARAMETERS:
 190  *      ip      - Inode pointer
 191  *      ealist  - EA list pointer
 192  *      size    - size of ealist in bytes
 193  *      ea      - dxd_t structure to be filled in appropriately with where the
 194  *                EA was copied
 195  *
 196  * NOTES: Will write EA inline if able to, otherwise allocates blocks for an
 197  *      extent and synchronously writes it to those blocks.
 198  *
 199  * RETURNS: 0 for success; Anything else indicates failure
 200  */
 201 static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size,
 202                        dxd_t * ea)
 203 {
 204         struct super_block *sb = ip->i_sb;
 205         struct jfs_inode_info *ji = JFS_IP(ip);
 206         struct jfs_sb_info *sbi = JFS_SBI(sb);
 207         int nblocks;
 208         s64 blkno;
 209         int rc = 0, i;
 210         char *cp;
 211         s32 nbytes, nb;
 212         s32 bytes_to_write;
 213         struct metapage *mp;
 214 
 215         /*
 216          * Quick check to see if this is an in-linable EA.  Short EAs
 217          * and empty EAs are all in-linable, provided the space exists.
 218          */
 219         if (!ealist || size <= sizeof (ji->i_inline_ea)) {
 220                 if (!ea_write_inline(ip, ealist, size, ea))
 221                         return 0;
 222         }
 223 
 224         /* figure out how many blocks we need */
 225         nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits;
 226 
 227         /* Allocate new blocks to quota. */
 228         rc = dquot_alloc_block(ip, nblocks);
 229         if (rc)
 230                 return rc;
 231 
 232         rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno);
 233         if (rc) {
 234                 /*Rollback quota allocation. */
 235                 dquot_free_block(ip, nblocks);
 236                 return rc;
 237         }
 238 
 239         /*
 240          * Now have nblocks worth of storage to stuff into the FEALIST.
 241          * loop over the FEALIST copying data into the buffer one page at
 242          * a time.
 243          */
 244         cp = (char *) ealist;
 245         nbytes = size;
 246         for (i = 0; i < nblocks; i += sbi->nbperpage) {
 247                 /*
 248                  * Determine how many bytes for this request, and round up to
 249                  * the nearest aggregate block size
 250                  */
 251                 nb = min(PSIZE, nbytes);
 252                 bytes_to_write =
 253                     ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
 254                     << sb->s_blocksize_bits;
 255 
 256                 if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) {
 257                         rc = -EIO;
 258                         goto failed;
 259                 }
 260 
 261                 memcpy(mp->data, cp, nb);
 262 
 263                 /*
 264                  * We really need a way to propagate errors for
 265                  * forced writes like this one.  --hch
 266                  *
 267                  * (__write_metapage => release_metapage => flush_metapage)
 268                  */
 269 #ifdef _JFS_FIXME
 270                 if ((rc = flush_metapage(mp))) {
 271                         /*
 272                          * the write failed -- this means that the buffer
 273                          * is still assigned and the blocks are not being
 274                          * used.  this seems like the best error recovery
 275                          * we can get ...
 276                          */
 277                         goto failed;
 278                 }
 279 #else
 280                 flush_metapage(mp);
 281 #endif
 282 
 283                 cp += PSIZE;
 284                 nbytes -= nb;
 285         }
 286 
 287         ea->flag = DXD_EXTENT;
 288         DXDsize(ea, le32_to_cpu(ealist->size));
 289         DXDlength(ea, nblocks);
 290         DXDaddress(ea, blkno);
 291 
 292         /* Free up INLINE area */
 293         if (ji->ea.flag & DXD_INLINE)
 294                 ji->mode2 |= INLINEEA;
 295 
 296         return 0;
 297 
 298       failed:
 299         /* Rollback quota allocation. */
 300         dquot_free_block(ip, nblocks);
 301 
 302         dbFree(ip, blkno, nblocks);
 303         return rc;
 304 }
 305 
 306 /*
 307  * NAME: ea_read_inline
 308  *
 309  * FUNCTION: Read an inlined EA into user's buffer
 310  *
 311  * PARAMETERS:
 312  *      ip      - Inode pointer
 313  *      ealist  - Pointer to buffer to fill in with EA
 314  *
 315  * RETURNS: 0
 316  */
 317 static int ea_read_inline(struct inode *ip, struct jfs_ea_list *ealist)
 318 {
 319         struct jfs_inode_info *ji = JFS_IP(ip);
 320         int ea_size = sizeDXD(&ji->ea);
 321 
 322         if (ea_size == 0) {
 323                 ealist->size = 0;
 324                 return 0;
 325         }
 326 
 327         /* Sanity Check */
 328         if ((sizeDXD(&ji->ea) > sizeof (ji->i_inline_ea)))
 329                 return -EIO;
 330         if (le32_to_cpu(((struct jfs_ea_list *) &ji->i_inline_ea)->size)
 331             != ea_size)
 332                 return -EIO;
 333 
 334         memcpy(ealist, ji->i_inline_ea, ea_size);
 335         return 0;
 336 }
 337 
 338 /*
 339  * NAME: ea_read
 340  *
 341  * FUNCTION: copy EA data into user's buffer
 342  *
 343  * PARAMETERS:
 344  *      ip      - Inode pointer
 345  *      ealist  - Pointer to buffer to fill in with EA
 346  *
 347  * NOTES:  If EA is inline calls ea_read_inline() to copy EA.
 348  *
 349  * RETURNS: 0 for success; other indicates failure
 350  */
 351 static int ea_read(struct inode *ip, struct jfs_ea_list *ealist)
 352 {
 353         struct super_block *sb = ip->i_sb;
 354         struct jfs_inode_info *ji = JFS_IP(ip);
 355         struct jfs_sb_info *sbi = JFS_SBI(sb);
 356         int nblocks;
 357         s64 blkno;
 358         char *cp = (char *) ealist;
 359         int i;
 360         int nbytes, nb;
 361         s32 bytes_to_read;
 362         struct metapage *mp;
 363 
 364         /* quick check for in-line EA */
 365         if (ji->ea.flag & DXD_INLINE)
 366                 return ea_read_inline(ip, ealist);
 367 
 368         nbytes = sizeDXD(&ji->ea);
 369         if (!nbytes) {
 370                 jfs_error(sb, "nbytes is 0\n");
 371                 return -EIO;
 372         }
 373 
 374         /*
 375          * Figure out how many blocks were allocated when this EA list was
 376          * originally written to disk.
 377          */
 378         nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage;
 379         blkno = addressDXD(&ji->ea) << sbi->l2nbperpage;
 380 
 381         /*
 382          * I have found the disk blocks which were originally used to store
 383          * the FEALIST.  now i loop over each contiguous block copying the
 384          * data into the buffer.
 385          */
 386         for (i = 0; i < nblocks; i += sbi->nbperpage) {
 387                 /*
 388                  * Determine how many bytes for this request, and round up to
 389                  * the nearest aggregate block size
 390                  */
 391                 nb = min(PSIZE, nbytes);
 392                 bytes_to_read =
 393                     ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
 394                     << sb->s_blocksize_bits;
 395 
 396                 if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1)))
 397                         return -EIO;
 398 
 399                 memcpy(cp, mp->data, nb);
 400                 release_metapage(mp);
 401 
 402                 cp += PSIZE;
 403                 nbytes -= nb;
 404         }
 405 
 406         return 0;
 407 }
 408 
 409 /*
 410  * NAME: ea_get
 411  *
 412  * FUNCTION: Returns buffer containing existing extended attributes.
 413  *           The size of the buffer will be the larger of the existing
 414  *           attributes size, or min_size.
 415  *
 416  *           The buffer, which may be inlined in the inode or in the
 417  *           page cache must be release by calling ea_release or ea_put
 418  *
 419  * PARAMETERS:
 420  *      inode   - Inode pointer
 421  *      ea_buf  - Structure to be populated with ealist and its metadata
 422  *      min_size- minimum size of buffer to be returned
 423  *
 424  * RETURNS: 0 for success; Other indicates failure
 425  */
 426 static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)
 427 {
 428         struct jfs_inode_info *ji = JFS_IP(inode);
 429         struct super_block *sb = inode->i_sb;
 430         int size;
 431         int ea_size = sizeDXD(&ji->ea);
 432         int blocks_needed, current_blocks;
 433         s64 blkno;
 434         int rc;
 435         int quota_allocation = 0;
 436 
 437         /* When fsck.jfs clears a bad ea, it doesn't clear the size */
 438         if (ji->ea.flag == 0)
 439                 ea_size = 0;
 440 
 441         if (ea_size == 0) {
 442                 if (min_size == 0) {
 443                         ea_buf->flag = 0;
 444                         ea_buf->max_size = 0;
 445                         ea_buf->xattr = NULL;
 446                         return 0;
 447                 }
 448                 if ((min_size <= sizeof (ji->i_inline_ea)) &&
 449                     (ji->mode2 & INLINEEA)) {
 450                         ea_buf->flag = EA_INLINE | EA_NEW;
 451                         ea_buf->max_size = sizeof (ji->i_inline_ea);
 452                         ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
 453                         DXDlength(&ea_buf->new_ea, 0);
 454                         DXDaddress(&ea_buf->new_ea, 0);
 455                         ea_buf->new_ea.flag = DXD_INLINE;
 456                         DXDsize(&ea_buf->new_ea, min_size);
 457                         return 0;
 458                 }
 459                 current_blocks = 0;
 460         } else if (ji->ea.flag & DXD_INLINE) {
 461                 if (min_size <= sizeof (ji->i_inline_ea)) {
 462                         ea_buf->flag = EA_INLINE;
 463                         ea_buf->max_size = sizeof (ji->i_inline_ea);
 464                         ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
 465                         goto size_check;
 466                 }
 467                 current_blocks = 0;
 468         } else {
 469                 if (!(ji->ea.flag & DXD_EXTENT)) {
 470                         jfs_error(sb, "invalid ea.flag\n");
 471                         return -EIO;
 472                 }
 473                 current_blocks = (ea_size + sb->s_blocksize - 1) >>
 474                     sb->s_blocksize_bits;
 475         }
 476         size = max(min_size, ea_size);
 477 
 478         if (size > PSIZE) {
 479                 /*
 480                  * To keep the rest of the code simple.  Allocate a
 481                  * contiguous buffer to work with. Make the buffer large
 482                  * enough to make use of the whole extent.
 483                  */
 484                 ea_buf->max_size = (size + sb->s_blocksize - 1) &
 485                     ~(sb->s_blocksize - 1);
 486 
 487                 ea_buf->xattr = kmalloc(ea_buf->max_size, GFP_KERNEL);
 488                 if (ea_buf->xattr == NULL)
 489                         return -ENOMEM;
 490 
 491                 ea_buf->flag = EA_MALLOC;
 492 
 493                 if (ea_size == 0)
 494                         return 0;
 495 
 496                 if ((rc = ea_read(inode, ea_buf->xattr))) {
 497                         kfree(ea_buf->xattr);
 498                         ea_buf->xattr = NULL;
 499                         return rc;
 500                 }
 501                 goto size_check;
 502         }
 503         blocks_needed = (min_size + sb->s_blocksize - 1) >>
 504             sb->s_blocksize_bits;
 505 
 506         if (blocks_needed > current_blocks) {
 507                 /* Allocate new blocks to quota. */
 508                 rc = dquot_alloc_block(inode, blocks_needed);
 509                 if (rc)
 510                         return -EDQUOT;
 511 
 512                 quota_allocation = blocks_needed;
 513 
 514                 rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed,
 515                              &blkno);
 516                 if (rc)
 517                         goto clean_up;
 518 
 519                 DXDlength(&ea_buf->new_ea, blocks_needed);
 520                 DXDaddress(&ea_buf->new_ea, blkno);
 521                 ea_buf->new_ea.flag = DXD_EXTENT;
 522                 DXDsize(&ea_buf->new_ea, min_size);
 523 
 524                 ea_buf->flag = EA_EXTENT | EA_NEW;
 525 
 526                 ea_buf->mp = get_metapage(inode, blkno,
 527                                           blocks_needed << sb->s_blocksize_bits,
 528                                           1);
 529                 if (ea_buf->mp == NULL) {
 530                         dbFree(inode, blkno, (s64) blocks_needed);
 531                         rc = -EIO;
 532                         goto clean_up;
 533                 }
 534                 ea_buf->xattr = ea_buf->mp->data;
 535                 ea_buf->max_size = (min_size + sb->s_blocksize - 1) &
 536                     ~(sb->s_blocksize - 1);
 537                 if (ea_size == 0)
 538                         return 0;
 539                 if ((rc = ea_read(inode, ea_buf->xattr))) {
 540                         discard_metapage(ea_buf->mp);
 541                         dbFree(inode, blkno, (s64) blocks_needed);
 542                         goto clean_up;
 543                 }
 544                 goto size_check;
 545         }
 546         ea_buf->flag = EA_EXTENT;
 547         ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea),
 548                                    lengthDXD(&ji->ea) << sb->s_blocksize_bits,
 549                                    1);
 550         if (ea_buf->mp == NULL) {
 551                 rc = -EIO;
 552                 goto clean_up;
 553         }
 554         ea_buf->xattr = ea_buf->mp->data;
 555         ea_buf->max_size = (ea_size + sb->s_blocksize - 1) &
 556             ~(sb->s_blocksize - 1);
 557 
 558       size_check:
 559         if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
 560                 printk(KERN_ERR "ea_get: invalid extended attribute\n");
 561                 print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,
 562                                      ea_buf->xattr, ea_size, 1);
 563                 ea_release(inode, ea_buf);
 564                 rc = -EIO;
 565                 goto clean_up;
 566         }
 567 
 568         return ea_size;
 569 
 570       clean_up:
 571         /* Rollback quota allocation */
 572         if (quota_allocation)
 573                 dquot_free_block(inode, quota_allocation);
 574 
 575         return (rc);
 576 }
 577 
 578 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf)
 579 {
 580         if (ea_buf->flag & EA_MALLOC)
 581                 kfree(ea_buf->xattr);
 582         else if (ea_buf->flag & EA_EXTENT) {
 583                 assert(ea_buf->mp);
 584                 release_metapage(ea_buf->mp);
 585 
 586                 if (ea_buf->flag & EA_NEW)
 587                         dbFree(inode, addressDXD(&ea_buf->new_ea),
 588                                lengthDXD(&ea_buf->new_ea));
 589         }
 590 }
 591 
 592 static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf,
 593                   int new_size)
 594 {
 595         struct jfs_inode_info *ji = JFS_IP(inode);
 596         unsigned long old_blocks, new_blocks;
 597         int rc = 0;
 598 
 599         if (new_size == 0) {
 600                 ea_release(inode, ea_buf);
 601                 ea_buf = NULL;
 602         } else if (ea_buf->flag & EA_INLINE) {
 603                 assert(new_size <= sizeof (ji->i_inline_ea));
 604                 ji->mode2 &= ~INLINEEA;
 605                 ea_buf->new_ea.flag = DXD_INLINE;
 606                 DXDsize(&ea_buf->new_ea, new_size);
 607                 DXDaddress(&ea_buf->new_ea, 0);
 608                 DXDlength(&ea_buf->new_ea, 0);
 609         } else if (ea_buf->flag & EA_MALLOC) {
 610                 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
 611                 kfree(ea_buf->xattr);
 612         } else if (ea_buf->flag & EA_NEW) {
 613                 /* We have already allocated a new dxd */
 614                 flush_metapage(ea_buf->mp);
 615         } else {
 616                 /* ->xattr must point to original ea's metapage */
 617                 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
 618                 discard_metapage(ea_buf->mp);
 619         }
 620         if (rc)
 621                 return rc;
 622 
 623         old_blocks = new_blocks = 0;
 624 
 625         if (ji->ea.flag & DXD_EXTENT) {
 626                 invalidate_dxd_metapages(inode, ji->ea);
 627                 old_blocks = lengthDXD(&ji->ea);
 628         }
 629 
 630         if (ea_buf) {
 631                 txEA(tid, inode, &ji->ea, &ea_buf->new_ea);
 632                 if (ea_buf->new_ea.flag & DXD_EXTENT) {
 633                         new_blocks = lengthDXD(&ea_buf->new_ea);
 634                         if (ji->ea.flag & DXD_INLINE)
 635                                 ji->mode2 |= INLINEEA;
 636                 }
 637                 ji->ea = ea_buf->new_ea;
 638         } else {
 639                 txEA(tid, inode, &ji->ea, NULL);
 640                 if (ji->ea.flag & DXD_INLINE)
 641                         ji->mode2 |= INLINEEA;
 642                 ji->ea.flag = 0;
 643                 ji->ea.size = 0;
 644         }
 645 
 646         /* If old blocks exist, they must be removed from quota allocation. */
 647         if (old_blocks)
 648                 dquot_free_block(inode, old_blocks);
 649 
 650         inode->i_ctime = current_time(inode);
 651 
 652         return 0;
 653 }
 654 
 655 int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name,
 656                    const void *value, size_t value_len, int flags)
 657 {
 658         struct jfs_ea_list *ealist;
 659         struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL;
 660         struct ea_buffer ea_buf;
 661         int old_ea_size = 0;
 662         int xattr_size;
 663         int new_size;
 664         int namelen = strlen(name);
 665         int found = 0;
 666         int rc;
 667         int length;
 668 
 669         down_write(&JFS_IP(inode)->xattr_sem);
 670 
 671         xattr_size = ea_get(inode, &ea_buf, 0);
 672         if (xattr_size < 0) {
 673                 rc = xattr_size;
 674                 goto out;
 675         }
 676 
 677       again:
 678         ealist = (struct jfs_ea_list *) ea_buf.xattr;
 679         new_size = sizeof (struct jfs_ea_list);
 680 
 681         if (xattr_size) {
 682                 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist);
 683                      ea = NEXT_EA(ea)) {
 684                         if ((namelen == ea->namelen) &&
 685                             (memcmp(name, ea->name, namelen) == 0)) {
 686                                 found = 1;
 687                                 if (flags & XATTR_CREATE) {
 688                                         rc = -EEXIST;
 689                                         goto release;
 690                                 }
 691                                 old_ea = ea;
 692                                 old_ea_size = EA_SIZE(ea);
 693                                 next_ea = NEXT_EA(ea);
 694                         } else
 695                                 new_size += EA_SIZE(ea);
 696                 }
 697         }
 698 
 699         if (!found) {
 700                 if (flags & XATTR_REPLACE) {
 701                         rc = -ENODATA;
 702                         goto release;
 703                 }
 704                 if (value == NULL) {
 705                         rc = 0;
 706                         goto release;
 707                 }
 708         }
 709         if (value)
 710                 new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len;
 711 
 712         if (new_size > ea_buf.max_size) {
 713                 /*
 714                  * We need to allocate more space for merged ea list.
 715                  * We should only have loop to again: once.
 716                  */
 717                 ea_release(inode, &ea_buf);
 718                 xattr_size = ea_get(inode, &ea_buf, new_size);
 719                 if (xattr_size < 0) {
 720                         rc = xattr_size;
 721                         goto out;
 722                 }
 723                 goto again;
 724         }
 725 
 726         /* Remove old ea of the same name */
 727         if (found) {
 728                 /* number of bytes following target EA */
 729                 length = (char *) END_EALIST(ealist) - (char *) next_ea;
 730                 if (length > 0)
 731                         memmove(old_ea, next_ea, length);
 732                 xattr_size -= old_ea_size;
 733         }
 734 
 735         /* Add new entry to the end */
 736         if (value) {
 737                 if (xattr_size == 0)
 738                         /* Completely new ea list */
 739                         xattr_size = sizeof (struct jfs_ea_list);
 740 
 741                 /*
 742                  * The size of EA value is limitted by on-disk format up to
 743                  *  __le16, there would be an overflow if the size is equal
 744                  * to XATTR_SIZE_MAX (65536).  In order to avoid this issue,
 745                  * we can pre-checkup the value size against USHRT_MAX, and
 746                  * return -E2BIG in this case, which is consistent with the
 747                  * VFS setxattr interface.
 748                  */
 749                 if (value_len >= USHRT_MAX) {
 750                         rc = -E2BIG;
 751                         goto release;
 752                 }
 753 
 754                 ea = (struct jfs_ea *) ((char *) ealist + xattr_size);
 755                 ea->flag = 0;
 756                 ea->namelen = namelen;
 757                 ea->valuelen = (cpu_to_le16(value_len));
 758                 memcpy(ea->name, name, namelen);
 759                 ea->name[namelen] = 0;
 760                 if (value_len)
 761                         memcpy(&ea->name[namelen + 1], value, value_len);
 762                 xattr_size += EA_SIZE(ea);
 763         }
 764 
 765         /* DEBUG - If we did this right, these number match */
 766         if (xattr_size != new_size) {
 767                 printk(KERN_ERR
 768                        "__jfs_setxattr: xattr_size = %d, new_size = %d\n",
 769                        xattr_size, new_size);
 770 
 771                 rc = -EINVAL;
 772                 goto release;
 773         }
 774 
 775         /*
 776          * If we're left with an empty list, there's no ea
 777          */
 778         if (new_size == sizeof (struct jfs_ea_list))
 779                 new_size = 0;
 780 
 781         ealist->size = cpu_to_le32(new_size);
 782 
 783         rc = ea_put(tid, inode, &ea_buf, new_size);
 784 
 785         goto out;
 786       release:
 787         ea_release(inode, &ea_buf);
 788       out:
 789         up_write(&JFS_IP(inode)->xattr_sem);
 790 
 791         return rc;
 792 }
 793 
 794 ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
 795                        size_t buf_size)
 796 {
 797         struct jfs_ea_list *ealist;
 798         struct jfs_ea *ea;
 799         struct ea_buffer ea_buf;
 800         int xattr_size;
 801         ssize_t size;
 802         int namelen = strlen(name);
 803         char *value;
 804 
 805         down_read(&JFS_IP(inode)->xattr_sem);
 806 
 807         xattr_size = ea_get(inode, &ea_buf, 0);
 808 
 809         if (xattr_size < 0) {
 810                 size = xattr_size;
 811                 goto out;
 812         }
 813 
 814         if (xattr_size == 0)
 815                 goto not_found;
 816 
 817         ealist = (struct jfs_ea_list *) ea_buf.xattr;
 818 
 819         /* Find the named attribute */
 820         for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
 821                 if ((namelen == ea->namelen) &&
 822                     memcmp(name, ea->name, namelen) == 0) {
 823                         /* Found it */
 824                         size = le16_to_cpu(ea->valuelen);
 825                         if (!data)
 826                                 goto release;
 827                         else if (size > buf_size) {
 828                                 size = -ERANGE;
 829                                 goto release;
 830                         }
 831                         value = ((char *) &ea->name) + ea->namelen + 1;
 832                         memcpy(data, value, size);
 833                         goto release;
 834                 }
 835       not_found:
 836         size = -ENODATA;
 837       release:
 838         ea_release(inode, &ea_buf);
 839       out:
 840         up_read(&JFS_IP(inode)->xattr_sem);
 841 
 842         return size;
 843 }
 844 
 845 /*
 846  * No special permissions are needed to list attributes except for trusted.*
 847  */
 848 static inline int can_list(struct jfs_ea *ea)
 849 {
 850         return (strncmp(ea->name, XATTR_TRUSTED_PREFIX,
 851                             XATTR_TRUSTED_PREFIX_LEN) ||
 852                 capable(CAP_SYS_ADMIN));
 853 }
 854 
 855 ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
 856 {
 857         struct inode *inode = d_inode(dentry);
 858         char *buffer;
 859         ssize_t size = 0;
 860         int xattr_size;
 861         struct jfs_ea_list *ealist;
 862         struct jfs_ea *ea;
 863         struct ea_buffer ea_buf;
 864 
 865         down_read(&JFS_IP(inode)->xattr_sem);
 866 
 867         xattr_size = ea_get(inode, &ea_buf, 0);
 868         if (xattr_size < 0) {
 869                 size = xattr_size;
 870                 goto out;
 871         }
 872 
 873         if (xattr_size == 0)
 874                 goto release;
 875 
 876         ealist = (struct jfs_ea_list *) ea_buf.xattr;
 877 
 878         /* compute required size of list */
 879         for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
 880                 if (can_list(ea))
 881                         size += name_size(ea) + 1;
 882         }
 883 
 884         if (!data)
 885                 goto release;
 886 
 887         if (size > buf_size) {
 888                 size = -ERANGE;
 889                 goto release;
 890         }
 891 
 892         /* Copy attribute names to buffer */
 893         buffer = data;
 894         for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
 895                 if (can_list(ea)) {
 896                         int namelen = copy_name(buffer, ea);
 897                         buffer += namelen + 1;
 898                 }
 899         }
 900 
 901       release:
 902         ea_release(inode, &ea_buf);
 903       out:
 904         up_read(&JFS_IP(inode)->xattr_sem);
 905         return size;
 906 }
 907 
 908 static int __jfs_xattr_set(struct inode *inode, const char *name,
 909                            const void *value, size_t size, int flags)
 910 {
 911         struct jfs_inode_info *ji = JFS_IP(inode);
 912         tid_t tid;
 913         int rc;
 914 
 915         tid = txBegin(inode->i_sb, 0);
 916         mutex_lock(&ji->commit_mutex);
 917         rc = __jfs_setxattr(tid, inode, name, value, size, flags);
 918         if (!rc)
 919                 rc = txCommit(tid, 1, &inode, 0);
 920         txEnd(tid);
 921         mutex_unlock(&ji->commit_mutex);
 922 
 923         return rc;
 924 }
 925 
 926 static int jfs_xattr_get(const struct xattr_handler *handler,
 927                          struct dentry *unused, struct inode *inode,
 928                          const char *name, void *value, size_t size)
 929 {
 930         name = xattr_full_name(handler, name);
 931         return __jfs_getxattr(inode, name, value, size);
 932 }
 933 
 934 static int jfs_xattr_set(const struct xattr_handler *handler,
 935                          struct dentry *unused, struct inode *inode,
 936                          const char *name, const void *value,
 937                          size_t size, int flags)
 938 {
 939         name = xattr_full_name(handler, name);
 940         return __jfs_xattr_set(inode, name, value, size, flags);
 941 }
 942 
 943 static int jfs_xattr_get_os2(const struct xattr_handler *handler,
 944                              struct dentry *unused, struct inode *inode,
 945                              const char *name, void *value, size_t size)
 946 {
 947         if (is_known_namespace(name))
 948                 return -EOPNOTSUPP;
 949         return __jfs_getxattr(inode, name, value, size);
 950 }
 951 
 952 static int jfs_xattr_set_os2(const struct xattr_handler *handler,
 953                              struct dentry *unused, struct inode *inode,
 954                              const char *name, const void *value,
 955                              size_t size, int flags)
 956 {
 957         if (is_known_namespace(name))
 958                 return -EOPNOTSUPP;
 959         return __jfs_xattr_set(inode, name, value, size, flags);
 960 }
 961 
 962 static const struct xattr_handler jfs_user_xattr_handler = {
 963         .prefix = XATTR_USER_PREFIX,
 964         .get = jfs_xattr_get,
 965         .set = jfs_xattr_set,
 966 };
 967 
 968 static const struct xattr_handler jfs_os2_xattr_handler = {
 969         .prefix = XATTR_OS2_PREFIX,
 970         .get = jfs_xattr_get_os2,
 971         .set = jfs_xattr_set_os2,
 972 };
 973 
 974 static const struct xattr_handler jfs_security_xattr_handler = {
 975         .prefix = XATTR_SECURITY_PREFIX,
 976         .get = jfs_xattr_get,
 977         .set = jfs_xattr_set,
 978 };
 979 
 980 static const struct xattr_handler jfs_trusted_xattr_handler = {
 981         .prefix = XATTR_TRUSTED_PREFIX,
 982         .get = jfs_xattr_get,
 983         .set = jfs_xattr_set,
 984 };
 985 
 986 const struct xattr_handler *jfs_xattr_handlers[] = {
 987 #ifdef CONFIG_JFS_POSIX_ACL
 988         &posix_acl_access_xattr_handler,
 989         &posix_acl_default_xattr_handler,
 990 #endif
 991         &jfs_os2_xattr_handler,
 992         &jfs_user_xattr_handler,
 993         &jfs_security_xattr_handler,
 994         &jfs_trusted_xattr_handler,
 995         NULL,
 996 };
 997 
 998 
 999 #ifdef CONFIG_JFS_SECURITY
1000 static int jfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
1001                           void *fs_info)
1002 {
1003         const struct xattr *xattr;
1004         tid_t *tid = fs_info;
1005         char *name;
1006         int err = 0;
1007 
1008         for (xattr = xattr_array; xattr->name != NULL; xattr++) {
1009                 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
1010                                strlen(xattr->name) + 1, GFP_NOFS);
1011                 if (!name) {
1012                         err = -ENOMEM;
1013                         break;
1014                 }
1015                 strcpy(name, XATTR_SECURITY_PREFIX);
1016                 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
1017 
1018                 err = __jfs_setxattr(*tid, inode, name,
1019                                      xattr->value, xattr->value_len, 0);
1020                 kfree(name);
1021                 if (err < 0)
1022                         break;
1023         }
1024         return err;
1025 }
1026 
1027 int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir,
1028                       const struct qstr *qstr)
1029 {
1030         return security_inode_init_security(inode, dir, qstr,
1031                                             &jfs_initxattrs, &tid);
1032 }
1033 #endif
/* [<][>][^][v][top][bottom][index][help] */
root/fs/jfs/xattr.c

DEFINITIONS
