src/afs/LINUX/osi_file.c

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 #include <afsconfig.h>
  11 #include "afs/param.h"
  12
  13
  14 #include <linux/module.h> /* early to avoid printf->printk mapping */
  15 #include "afs/sysincludes.h"    /* Standard vendor system headers */
  16 #include "afsincludes.h"        /* Afs-based standard headers */
  17 #include "afs/afs_stats.h"      /* afs statistics */
  18 #include <linux/namei.h>
  19
  20 #if defined(HAVE_LINUX_EXPORTFS_H)
  21 #include <linux/exportfs.h>
  22 #endif
  23 #include "osi_compat.h"
  24
  25 #ifndef CURRENT_TIME
  26 # if defined(HAVE_LINUX_KTIME_GET_COARSE_REAL_TS64)
  27 #   define AFS_CURRENT_TIME(x) (ktime_get_coarse_real_ts64((x)))
  28 # else
  29 #  ifdef IATTR_TAKES_64BIT_TIME
  30 #    define AFS_CURRENT_TIME(x) do {*(x) = current_kernel_time64();} while (0)
  31 #  else
  32 #    define AFS_CURRENT_TIME(x) do {*(x) = current_kernel_time();} while (0)
  33 #  endif
  34 # endif
  35 #else
  36 # define AFS_CURRENT_TIME(x) do {*(x) = CURRENT_TIME;} while(0)
  37 #endif
  38
  39 int cache_fh_type = -1;
  40 int cache_fh_len = -1;
  41
  42 extern struct osi_dev cacheDev;
  43 extern struct vfsmount *afs_cacheMnt;
  44 extern struct super_block *afs_cacheSBp;
  45 #if defined(STRUCT_TASK_STRUCT_HAS_CRED)
  46 extern struct cred *cache_creds;
  47 #endif
  48
  49 /* Old export ops: decode_fh will call back here. Accept any dentry it suggests */
  50 int
  51 afs_fh_acceptable(void *context, struct dentry *dp)
  52 {
  53     return 1;
  54 }
  55
  56 struct file *
  57 afs_linux_raw_open(afs_dcache_id_t *ainode)
  58 {
  59     struct inode *tip = NULL;
  60     struct dentry *dp = NULL;
  61     struct file* filp;
  62
  63     dp = afs_get_dentry_from_fh(afs_cacheSBp, ainode, cache_fh_len, cache_fh_type,
  64                 afs_fh_acceptable);
  65     if ((!dp) || IS_ERR(dp))
  66            osi_Panic("Can't get dentry\n");
  67     tip = dp->d_inode;
  68     tip->i_flags |= S_NOATIME;  /* Disable updating access times. */
  69
  70 #if defined(STRUCT_TASK_STRUCT_HAS_CRED)
  71     /* Use stashed credentials - prevent selinux/apparmor problems  */
  72     filp = afs_dentry_open(dp, afs_cacheMnt, O_RDWR, cache_creds);
  73     if (IS_ERR(filp))
  74         filp = afs_dentry_open(dp, afs_cacheMnt, O_RDWR, current_cred());
  75 #else
  76     filp = dentry_open(dget(dp), mntget(afs_cacheMnt), O_RDWR);
  77 #endif
  78     if (IS_ERR(filp)) {
  79         afs_warn("afs: Cannot open cache file (code %d). Trying to continue, "
  80                  "but AFS accesses may return errors or panic the system\n",
  81                  (int) PTR_ERR(filp));
  82         filp = NULL;
  83     }
  84
  85     dput(dp);
  86
  87     return filp;
  88 }
  89
  90 void *
  91 osi_UFSOpen(afs_dcache_id_t *ainode)
  92 {
  93     struct osi_file *afile = NULL;
  94     extern int cacheDiskType;
  95
  96     AFS_STATCNT(osi_UFSOpen);
  97     if (cacheDiskType != AFS_FCACHE_TYPE_UFS) {
  98         osi_Panic("UFSOpen called for non-UFS cache\n");
  99     }
 100     if (!afs_osicred_initialized) {
 101         /* valid for alpha_osf, SunOS, Ultrix */
 102         memset(&afs_osi_cred, 0, sizeof(afs_ucred_t));
 103         crhold(&afs_osi_cred);  /* don't let it evaporate, since it is static */
 104         afs_osicred_initialized = 1;
 105     }
 106     AFS_GUNLOCK();
 107     afile = kmalloc(sizeof(struct osi_file), GFP_NOFS);
 108     if (!afile) {
 109         osi_Panic("osi_UFSOpen: Failed to allocate %d bytes for osi_file.\n",
 110                   (int)sizeof(struct osi_file));
 111     }
 112     memset(afile, 0, sizeof(struct osi_file));
 113
 114     afile->filp = afs_linux_raw_open(ainode);
 115     if (afile->filp) {
 116         afile->size = i_size_read(FILE_INODE(afile->filp));
 117     }
 118     AFS_GLOCK();
 119
 120     if (!afile->filp) {
 121         osi_FreeLargeSpace(afile);
 122         return NULL;
 123     }
 124
 125     afile->offset = 0;
 126     afile->proc = (int (*)())0;
 127     return (void *)afile;
 128 }
 129
 130 /*
 131  * Given a dentry, return the file handle as encoded by the filesystem.
 132  * We can't assume anything about the length (words, not bytes).
 133  * The cache has to live on a single filesystem with uniform file
 134  * handles, otherwise we panic.
 135  */
 136 void osi_get_fh(struct dentry *dp, afs_ufs_dcache_id_t *ainode) {
 137     int max_len;
 138     int type;
 139
 140     if (cache_fh_len > 0)
 141         max_len = cache_fh_len;
 142     else
 143         max_len = MAX_FH_LEN;
 144     type = afs_get_fh_from_dentry(dp, ainode, &max_len);
 145     if (type == 255) {
 146         osi_Panic("File handle encoding failed\n");
 147     }
 148     if (cache_fh_type < 0)
 149         cache_fh_type = type;
 150     if (cache_fh_len < 0) {
 151         cache_fh_len = max_len;
 152     }
 153     if (type != cache_fh_type || max_len != cache_fh_len) {
 154         osi_Panic("Inconsistent file handles within cache\n");
 155     }
 156 }
 157
 158 int
 159 afs_osi_Stat(struct osi_file *afile, struct osi_stat *astat)
 160 {
 161     AFS_STATCNT(osi_Stat);
 162     astat->size = i_size_read(OSIFILE_INODE(afile));
 163     astat->mtime = OSIFILE_INODE(afile)->i_mtime.tv_sec;
 164     astat->atime = OSIFILE_INODE(afile)->i_atime.tv_sec;
 165
 166     return 0;
 167 }
 168
 169 int
 170 osi_UFSClose(struct osi_file *afile)
 171 {
 172     AFS_STATCNT(osi_Close);
 173     if (afile) {
 174         if (OSIFILE_INODE(afile)) {
 175             filp_close(afile->filp, NULL);
 176         }
 177     }
 178     kfree(afile);
 179     return 0;
 180 }
 181
 182 int
 183 osi_UFSTruncate(struct osi_file *afile, afs_int32 asize)
 184 {
 185     afs_int32 code;
 186     struct osi_stat tstat;
 187     struct iattr newattrs;
 188     struct inode *inode = OSIFILE_INODE(afile);
 189     AFS_STATCNT(osi_Truncate);
 190
 191     /* This routine only shrinks files, and most systems
 192      * have very slow truncates, even when the file is already
 193      * small enough.  Check now and save some time.
 194      */
 195     code = afs_osi_Stat(afile, &tstat);
 196     if (code || tstat.size <= asize)
 197         return code;
 198     AFS_GUNLOCK();
 199     afs_linux_lock_inode(inode);
 200 #ifdef STRUCT_INODE_HAS_I_ALLOC_SEM
 201     down_write(&inode->i_alloc_sem);
 202 #endif
 203     newattrs.ia_size = asize;
 204     newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
 205     AFS_CURRENT_TIME(&newattrs.ia_ctime);
 206
 207     /* avoid notify_change() since it wants to update dentry->d_parent */
 208 #ifdef HAVE_LINUX_SETATTR_PREPARE
 209     code = setattr_prepare(file_dentry(afile->filp), &newattrs);
 210 #else
 211     code = inode_change_ok(inode, &newattrs);
 212 #endif
 213     if (!code)
 214         code = afs_inode_setattr(afile, &newattrs);
 215     if (!code)
 216         truncate_inode_pages(&inode->i_data, asize);
 217     code = -code;
 218 #ifdef STRUCT_INODE_HAS_I_ALLOC_SEM
 219     up_write(&inode->i_alloc_sem);
 220 #endif
 221     afs_linux_unlock_inode(inode);
 222     AFS_GLOCK();
 223     return code;
 224 }
 225
 226
 227 /* Generic read interface */
 228 int
 229 afs_osi_Read(struct osi_file *afile, int offset, void *aptr,
 230              afs_int32 asize)
 231 {
 232     struct uio auio;
 233     struct iovec iov;
 234     afs_int32 code;
 235
 236     memset(&auio, 0, sizeof(auio));
 237     memset(&iov, 0, sizeof(iov));
 238
 239     AFS_STATCNT(osi_Read);
 240
 241     /*
 242      * If the osi_file passed in is NULL, panic only if AFS is not shutting
 243      * down. No point in crashing when we are already shutting down
 244      */
 245     if (!afile) {
 246         if (afs_shuttingdown == AFS_RUNNING)
 247             osi_Panic("osi_Read called with null param");
 248         else
 249             return -EIO;
 250     }
 251
 252     if (offset != -1)
 253         afile->offset = offset;
 254     setup_uio(&auio, &iov, aptr, afile->offset, asize, UIO_READ, AFS_UIOSYS);
 255     AFS_GUNLOCK();
 256     code = osi_rdwr(afile, &auio, UIO_READ);
 257     AFS_GLOCK();
 258     if (code == 0) {
 259         code = asize - auio.uio_resid;
 260         afile->offset += code;
 261     } else {
 262         afs_Trace2(afs_iclSetp, CM_TRACE_READFAILED, ICL_TYPE_INT32, auio.uio_resid,
 263                    ICL_TYPE_INT32, code);
 264         if (code > 0) {
 265             code = -code;
 266         }
 267     }
 268     return code;
 269 }
 270
 271 /* Generic write interface */
 272 int
 273 afs_osi_Write(struct osi_file *afile, afs_int32 offset, void *aptr,
 274               afs_int32 asize)
 275 {
 276     struct uio auio;
 277     struct iovec iov;
 278     afs_int32 code;
 279
 280     memset(&auio, 0, sizeof(auio));
 281     memset(&iov, 0, sizeof(iov));
 282
 283     AFS_STATCNT(osi_Write);
 284
 285     if (!afile) {
 286         if (afs_shuttingdown == AFS_RUNNING)
 287             osi_Panic("afs_osi_Write called with null param");
 288         else
 289             return -EIO;
 290     }
 291
 292     if (offset != -1)
 293         afile->offset = offset;
 294     setup_uio(&auio, &iov, aptr, afile->offset, asize, UIO_WRITE, AFS_UIOSYS);
 295     AFS_GUNLOCK();
 296     code = osi_rdwr(afile, &auio, UIO_WRITE);
 297     AFS_GLOCK();
 298     if (code == 0) {
 299         code = asize - auio.uio_resid;
 300         afile->offset += code;
 301     } else {
 302         if (code == ENOSPC)
 303             afs_WarnENOSPC();
 304         if (code > 0) {
 305             code = -code;
 306         }
 307     }
 308
 309     if (afile->proc)
 310         (*afile->proc)(afile, code);
 311
 312     return code;
 313 }
 314
 315
 316 /*  This work should be handled by physstrat in ca/machdep.c.
 317     This routine written from the RT NFS port strategy routine.
 318     It has been generalized a bit, but should still be pretty clear. */
 319 int
 320 afs_osi_MapStrategy(int (*aproc) (struct buf * bp), struct buf *bp)
 321 {
 322     afs_int32 returnCode;
 323
 324     AFS_STATCNT(osi_MapStrategy);
 325     returnCode = (*aproc) (bp);
 326
 327     return returnCode;
 328 }
 329
 330 void
 331 shutdown_osifile(void)
 332 {
 333     AFS_STATCNT(shutdown_osifile);
 334     if (afs_cold_shutdown) {
 335         afs_osicred_initialized = 0;
 336     }
 337 }
 338
 339 /* Intialize cache device info and fragment size for disk cache partition. */
 340 int
 341 osi_InitCacheInfo(char *aname)
 342 {
 343     int code;
 344     extern afs_dcache_id_t cacheInode;
 345     struct dentry *dp;
 346     extern struct osi_dev cacheDev;
 347     extern afs_int32 afs_fsfragsize;
 348     extern struct super_block *afs_cacheSBp;
 349     extern struct vfsmount *afs_cacheMnt;
 350     code = osi_lookupname_internal(aname, 1, &afs_cacheMnt, &dp);
 351     if (code)
 352         return ENOENT;
 353
 354     osi_get_fh(dp, &cacheInode.ufs);
 355     cacheDev.dev = dp->d_inode->i_sb->s_dev;
 356     afs_fsfragsize = dp->d_inode->i_sb->s_blocksize - 1;
 357     afs_cacheSBp = dp->d_inode->i_sb;
 358
 359     dput(dp);
 360
 361     afs_init_sb_export_ops(afs_cacheSBp);
 362
 363     return 0;
 364 }
 365
 366
 367 /* osi_rdwr
 368  * seek, then read or write to an open inode. addrp points to data in
 369  * kernel space.
 370  */
 371 int
 372 osi_rdwr(struct osi_file *osifile, struct uio *uiop, int rw)
 373 {
 374     struct file *filp = osifile->filp;
 375 #ifdef AFS_FILE_NEEDS_SET_FS
 376     mm_segment_t old_fs = {0};
 377 #endif /* AFS_FILE_NEEDS_SET_FS */
 378     int code = 0;
 379     struct iovec *iov;
 380     size_t count;
 381     unsigned long savelim;
 382     loff_t pos;
 383
 384     savelim = current->TASK_STRUCT_RLIM[RLIMIT_FSIZE].rlim_cur;
 385     current->TASK_STRUCT_RLIM[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
 386
 387 #ifdef AFS_FILE_NEEDS_SET_FS
 388     if (uiop->uio_seg == AFS_UIOSYS) {
 389         /* Switch into user space */
 390         old_fs = get_fs();
 391         set_fs(get_ds());
 392     }
 393 #endif /* AFS_FILE_NEEDS_SET_FS */
 394
 395     while (code == 0 && uiop->uio_resid > 0 && uiop->uio_iovcnt > 0) {
 396         iov = uiop->uio_iov;
 397         count = iov->iov_len;
 398         if (count == 0) {
 399             uiop->uio_iov++;
 400             uiop->uio_iovcnt--;
 401             continue;
 402         }
 403
 404         pos = uiop->uio_offset;
 405         if (rw == UIO_READ)
 406             code = afs_file_read(filp, iov->iov_base, count, &pos);
 407         else
 408             code = afs_file_write(filp, iov->iov_base, count, &pos);
 409
 410         if (code < 0) {
 411             code = -code;
 412             break;
 413         } else if (code == 0) {
 414             /*
 415              * This is bad -- we can't read any more data from the
 416              * file, but we have no good way of signaling a partial
 417              * read either.
 418              */
 419             code = EIO;
 420             break;
 421         }
 422
 423         iov->iov_base += code;
 424         iov->iov_len -= code;
 425         uiop->uio_resid -= code;
 426         uiop->uio_offset += code;
 427         code = 0;
 428     }
 429
 430 #ifdef AFS_FILE_NEEDS_SET_FS
 431     if (uiop->uio_seg == AFS_UIOSYS) {
 432         /* Switch back into kernel space */
 433         set_fs(old_fs);
 434     }
 435 #endif /* AFS_FILE_NEEDS_SET_FS */
 436
 437     current->TASK_STRUCT_RLIM[RLIMIT_FSIZE].rlim_cur = savelim;
 438
 439     return code;
 440 }
 441
 442 /* setup_uio
 443  * Setup a uio struct.
 444  */
 445 void
 446 setup_uio(struct uio *uiop, struct iovec *iovecp, const char *buf, afs_offs_t pos,
 447           int count, uio_flag_t flag, uio_seg_t seg)
 448 {
 449     iovecp->iov_base = (char *)buf;
 450     iovecp->iov_len = count;
 451     uiop->uio_iov = iovecp;
 452     uiop->uio_iovcnt = 1;
 453     uiop->uio_offset = pos;
 454     uiop->uio_seg = seg;
 455     uiop->uio_resid = count;
 456     uiop->uio_flag = flag;
 457 }
 458
 459
 460 /* uiomove
 461  * UIO_READ : dp -> uio
 462  * UIO_WRITE : uio -> dp
 463  */
 464 int
 465 uiomove(char *dp, int length, uio_flag_t rw, struct uio *uiop)
 466 {
 467     int count;
 468     struct iovec *iov;
 469     int code;
 470
 471     while (length > 0 && uiop->uio_resid > 0 && uiop->uio_iovcnt > 0) {
 472         iov = uiop->uio_iov;
 473         count = iov->iov_len;
 474
 475         if (!count) {
 476             uiop->uio_iov++;
 477             uiop->uio_iovcnt--;
 478             continue;
 479         }
 480
 481         if (count > length)
 482             count = length;
 483
 484         switch (uiop->uio_seg) {
 485         case AFS_UIOSYS:
 486             switch (rw) {
 487             case UIO_READ:
 488                 memcpy(iov->iov_base, dp, count);
 489                 break;
 490             case UIO_WRITE:
 491                 memcpy(dp, iov->iov_base, count);
 492                 break;
 493             default:
 494                 printf("uiomove: Bad rw = %d\n", rw);
 495                 return -EINVAL;
 496             }
 497             break;
 498         case AFS_UIOUSER:
 499             switch (rw) {
 500             case UIO_READ:
 501                 AFS_COPYOUT(dp, iov->iov_base, count, code);
 502                 break;
 503             case UIO_WRITE:
 504                 AFS_COPYIN(iov->iov_base, dp, count, code);
 505                 break;
 506             default:
 507                 printf("uiomove: Bad rw = %d\n", rw);
 508                 return -EINVAL;
 509             }
 510             break;
 511         default:
 512             printf("uiomove: Bad seg = %d\n", uiop->uio_seg);
 513             return -EINVAL;
 514         }
 515
 516         dp += count;
 517         length -= count;
 518         iov->iov_base += count;
 519         iov->iov_len -= count;
 520         uiop->uio_offset += count;
 521         uiop->uio_resid -= count;
 522     }
 523     return 0;
 524 }
 525