]> git.sven.stormbind.net Git - sven/exfat-utils.git/blobdiff - libexfat/io.c
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[sven/exfat-utils.git] / libexfat / io.c
index c9c1e2bc324e5661dbc51931632ef9b00a26cddf..3d7aaad2e903db2f2dbacd56d8bac62816560f46 100644 (file)
@@ -2,11 +2,12 @@
        io.c (02.09.09)
        exFAT file system implementation library.
 
-       Copyright (C) 2009, 2010  Andrew Nayenko
+       Free exFAT implementation.
+       Copyright (C) 2010-2015  Andrew Nayenko
 
-       This program is free software: you can redistribute it and/or modify
+       This program is free software; you can redistribute it and/or modify
        it under the terms of the GNU General Public License as published by
-       the Free Software Foundation, either version 3 of the License, or
+       the Free Software Foundation, either version 2 of the License, or
        (at your option) any later version.
 
        This program is distributed in the hope that it will be useful,
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU General Public License for more details.
 
-       You should have received a copy of the GNU General Public License
-       along with this program.  If not, see <http://www.gnu.org/licenses/>.
+       You should have received a copy of the GNU General Public License along
+       with this program; if not, write to the Free Software Foundation, Inc.,
+       51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
-#define _XOPEN_SOURCE 500 /* for pread() and pwrite() in Linux */
 #include "exfat.h"
 #include <inttypes.h>
 #include <sys/types.h>
-#include <sys/uio.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <string.h>
+#include <errno.h>
+#if defined(__APPLE__)
+#include <sys/disk.h>
+#elif defined(__OpenBSD__)
+#include <sys/param.h>
+#include <sys/disklabel.h>
+#include <sys/dkio.h>
+#include <sys/ioctl.h>
+#endif
+#include <sys/mount.h>
 #ifdef USE_UBLIO
 #include <sys/uio.h>
 #include <ublio.h>
 #endif
 
-#if _FILE_OFFSET_BITS != 64
-       #error You should define _FILE_OFFSET_BITS=64
-#endif
-
 struct exfat_dev
 {
        int fd;
+       enum exfat_mode mode;
+       off_t size; /* in bytes */
 #ifdef USE_UBLIO
        off_t pos;
        ublio_filehandle_t ufh;
 #endif
 };
 
-struct exfat_dev* exfat_open(const char* spec, int ro)
+static int open_ro(const char* spec)
+{
+       return open(spec, O_RDONLY);
+}
+
+static int open_rw(const char* spec)
+{
+       int fd = open(spec, O_RDWR);
+#ifdef __linux__
+       int ro = 0;
+
+       /*
+          This ioctl is needed because after "blockdev --setro" kernel still
+          allows to open the device in read-write mode but fails writes.
+       */
+       if (fd != -1 && ioctl(fd, BLKROGET, &ro) == 0 && ro)
+       {
+               close(fd);
+               errno = EROFS;
+               return -1;
+       }
+#endif
+       return fd;
+}
+
+struct exfat_dev* exfat_open(const char* spec, enum exfat_mode mode)
 {
        struct exfat_dev* dev;
        struct stat stbuf;
@@ -60,19 +93,54 @@ struct exfat_dev* exfat_open(const char* spec, int ro)
                return NULL;
        }
 
-       dev->fd = open(spec, ro ? O_RDONLY : O_RDWR);
-       if (dev->fd < 0)
+       switch (mode)
        {
+       case EXFAT_MODE_RO:
+               dev->fd = open_ro(spec);
+               if (dev->fd == -1)
+               {
+                       free(dev);
+                       exfat_error("failed to open '%s' in read-only mode: %s", spec,
+                                       strerror(errno));
+                       return NULL;
+               }
+               dev->mode = EXFAT_MODE_RO;
+               break;
+       case EXFAT_MODE_RW:
+               dev->fd = open_rw(spec);
+               if (dev->fd == -1)
+               {
+                       free(dev);
+                       exfat_error("failed to open '%s' in read-write mode: %s", spec,
+                                       strerror(errno));
+                       return NULL;
+               }
+               dev->mode = EXFAT_MODE_RW;
+               break;
+       case EXFAT_MODE_ANY:
+               dev->fd = open_rw(spec);
+               if (dev->fd != -1)
+               {
+                       dev->mode = EXFAT_MODE_RW;
+                       break;
+               }
+               dev->fd = open_ro(spec);
+               if (dev->fd != -1)
+               {
+                       dev->mode = EXFAT_MODE_RO;
+                       exfat_warn("'%s' is write-protected, mounting read-only", spec);
+                       break;
+               }
                free(dev);
-               exfat_error("failed to open `%s' in read-%s mode", spec,
-                               ro ? "only" : "write");
+               exfat_error("failed to open '%s': %s", spec, strerror(errno));
                return NULL;
        }
+
        if (fstat(dev->fd, &stbuf) != 0)
        {
                close(dev->fd);
                free(dev);
-               exfat_error("failed to fstat `%s'", spec);
+               exfat_error("failed to fstat '%s'", spec);
                return NULL;
        }
        if (!S_ISBLK(stbuf.st_mode) &&
@@ -81,10 +149,79 @@ struct exfat_dev* exfat_open(const char* spec, int ro)
        {
                close(dev->fd);
                free(dev);
-               exfat_error("`%s' is neither a device, nor a regular file", spec);
+               exfat_error("'%s' is neither a device, nor a regular file", spec);
                return NULL;
        }
 
+#if defined(__APPLE__)
+       if (!S_ISREG(stbuf.st_mode))
+       {
+               uint32_t block_size = 0;
+               uint64_t blocks = 0;
+
+               if (ioctl(dev->fd, DKIOCGETBLOCKSIZE, &block_size) != 0)
+               {
+                       close(dev->fd);
+                       free(dev);
+                       exfat_error("failed to get block size");
+                       return NULL;
+               }
+               if (ioctl(dev->fd, DKIOCGETBLOCKCOUNT, &blocks) != 0)
+               {
+                       close(dev->fd);
+                       free(dev);
+                       exfat_error("failed to get blocks count");
+                       return NULL;
+               }
+               dev->size = blocks * block_size;
+       }
+       else
+#elif defined(__OpenBSD__)
+       if (!S_ISREG(stbuf.st_mode))
+       {
+               struct disklabel lab;
+               struct partition* pp;
+               char* partition;
+
+               if (ioctl(dev->fd, DIOCGDINFO, &lab) == -1)
+               {
+                       close(dev->fd);
+                       free(dev);
+                       exfat_error("failed to get disklabel");
+                       return NULL;
+               }
+
+               /* Don't need to check that partition letter is valid as we won't get
+                  this far otherwise. */
+               partition = strchr(spec, '\0') - 1;
+               pp = &(lab.d_partitions[*partition - 'a']);
+               dev->size = DL_GETPSIZE(pp) * lab.d_secsize;
+
+               if (pp->p_fstype != FS_NTFS)
+                       exfat_warn("partition type is not 0x07 (NTFS/exFAT); "
+                                       "you can fix this with fdisk(8)");
+       }
+       else
+#endif
+       {
+               /* works for Linux, FreeBSD, Solaris */
+               dev->size = exfat_seek(dev, 0, SEEK_END);
+               if (dev->size <= 0)
+               {
+                       close(dev->fd);
+                       free(dev);
+                       exfat_error("failed to get size of '%s'", spec);
+                       return NULL;
+               }
+               if (exfat_seek(dev, 0, SEEK_SET) == -1)
+               {
+                       close(dev->fd);
+                       free(dev);
+                       exfat_error("failed to seek to the beginning of '%s'", spec);
+                       return NULL;
+               }
+       }
+
 #ifdef USE_UBLIO
        memset(&up, 0, sizeof(struct ublio_param));
        up.up_blocksize = 256 * 1024;
@@ -108,32 +245,51 @@ struct exfat_dev* exfat_open(const char* spec, int ro)
 
 int exfat_close(struct exfat_dev* dev)
 {
+       int rc = 0;
+
 #ifdef USE_UBLIO
        if (ublio_close(dev->ufh) != 0)
+       {
                exfat_error("failed to close ublio");
+               rc = -EIO;
+       }
 #endif
        if (close(dev->fd) != 0)
        {
-               free(dev);
-               exfat_error("failed to close device");
-               return 1;
+               exfat_error("failed to close device: %s", strerror(errno));
+               rc = -EIO;
        }
        free(dev);
-       return 0;
+       return rc;
 }
 
 int exfat_fsync(struct exfat_dev* dev)
 {
+       int rc = 0;
+
 #ifdef USE_UBLIO
        if (ublio_fsync(dev->ufh) != 0)
-#else
-       if (fsync(dev->fd) != 0)
+       {
+               exfat_error("ublio fsync failed");
+               rc = -EIO;
+       }
 #endif
+       if (fsync(dev->fd) != 0)
        {
-               exfat_error("fsync failed");
-               return 1;
+               exfat_error("fsync failed: %s", strerror(errno));
+               rc = -EIO;
        }
-       return 0;
+       return rc;
+}
+
+enum exfat_mode exfat_get_mode(const struct exfat_dev* dev)
+{
+       return dev->mode;
+}
+
+off_t exfat_get_size(const struct exfat_dev* dev)
+{
+       return dev->size;
 }
 
 off_t exfat_seek(struct exfat_dev* dev, off_t offset, int whence)
@@ -170,28 +326,24 @@ ssize_t exfat_write(struct exfat_dev* dev, const void* buffer, size_t size)
 #endif
 }
 
-void exfat_pread(struct exfat_dev* dev, void* buffer, size_t size,
+ssize_t exfat_pread(struct exfat_dev* dev, void* buffer, size_t size,
                off_t offset)
 {
 #ifdef USE_UBLIO
-       if (ublio_pread(dev->ufh, buffer, size, offset) != size)
+       return ublio_pread(dev->ufh, buffer, size, offset);
 #else
-       if (pread(dev->fd, buffer, size, offset) != size)
+       return pread(dev->fd, buffer, size, offset);
 #endif
-               exfat_bug("failed to read %zu bytes from file at %"PRIu64, size,
-                               (uint64_t) offset);
 }
 
-void exfat_pwrite(struct exfat_dev* dev, const void* buffer, size_t size,
+ssize_t exfat_pwrite(struct exfat_dev* dev, const void* buffer, size_t size,
                off_t offset)
 {
 #ifdef USE_UBLIO
-       if (ublio_pwrite(dev->ufh, buffer, size, offset) != size)
+       return ublio_pwrite(dev->ufh, buffer, size, offset);
 #else
-       if (pwrite(dev->fd, buffer, size, offset) != size)
+       return pwrite(dev->fd, buffer, size, offset);
 #endif
-               exfat_bug("failed to write %zu bytes to file at %"PRIu64, size,
-                               (uint64_t) offset);
 }
 
 ssize_t exfat_generic_pread(const struct exfat* ef, struct exfat_node* node,
@@ -209,7 +361,7 @@ ssize_t exfat_generic_pread(const struct exfat* ef, struct exfat_node* node,
        cluster = exfat_advance_cluster(ef, node, offset / CLUSTER_SIZE(*ef->sb));
        if (CLUSTER_INVALID(cluster))
        {
-               exfat_error("got invalid cluster");
+               exfat_error("invalid cluster 0x%x while reading", cluster);
                return -1;
        }
 
@@ -219,11 +371,16 @@ ssize_t exfat_generic_pread(const struct exfat* ef, struct exfat_node* node,
        {
                if (CLUSTER_INVALID(cluster))
                {
-                       exfat_error("got invalid cluster");
+                       exfat_error("invalid cluster 0x%x while reading", cluster);
                        return -1;
                }
                lsize = MIN(CLUSTER_SIZE(*ef->sb) - loffset, remainder);
-               exfat_pread(ef->dev, bufp, lsize, exfat_c2o(ef, cluster) + loffset);
+               if (exfat_pread(ef->dev, bufp, lsize,
+                                       exfat_c2o(ef, cluster) + loffset) < 0)
+               {
+                       exfat_error("failed to read cluster %#x", cluster);
+                       return -1;
+               }
                bufp += lsize;
                loffset = 0;
                remainder -= lsize;
@@ -231,7 +388,7 @@ ssize_t exfat_generic_pread(const struct exfat* ef, struct exfat_node* node,
        }
        if (!ef->ro && !ef->noatime)
                exfat_update_atime(node);
-       return size - remainder;
+       return MIN(size, node->size - offset) - remainder;
 }
 
 ssize_t exfat_generic_pwrite(struct exfat* ef, struct exfat_node* node,
@@ -241,19 +398,19 @@ ssize_t exfat_generic_pwrite(struct exfat* ef, struct exfat_node* node,
        const char* bufp = buffer;
        off_t lsize, loffset, remainder;
 
-       if (offset + size > node->size)
-       {
-               int rc = exfat_truncate(ef, node, offset + size);
-               if (rc != 0)
-                       return rc;
-       }
+       if (offset > node->size)
+               if (exfat_truncate(ef, node, offset, true) != 0)
+                       return -1;
+       if (offset + size > node->size)
+               if (exfat_truncate(ef, node, offset + size, false) != 0)
+                       return -1;
        if (size == 0)
                return 0;
 
        cluster = exfat_advance_cluster(ef, node, offset / CLUSTER_SIZE(*ef->sb));
        if (CLUSTER_INVALID(cluster))
        {
-               exfat_error("got invalid cluster");
+               exfat_error("invalid cluster 0x%x while writing", cluster);
                return -1;
        }
 
@@ -263,11 +420,16 @@ ssize_t exfat_generic_pwrite(struct exfat* ef, struct exfat_node* node,
        {
                if (CLUSTER_INVALID(cluster))
                {
-                       exfat_error("got invalid cluster");
+                       exfat_error("invalid cluster 0x%x while writing", cluster);
                        return -1;
                }
                lsize = MIN(CLUSTER_SIZE(*ef->sb) - loffset, remainder);
-               exfat_pwrite(ef->dev, bufp, lsize, exfat_c2o(ef, cluster) + loffset);
+               if (exfat_pwrite(ef->dev, bufp, lsize,
+                               exfat_c2o(ef, cluster) + loffset) < 0)
+               {
+                       exfat_error("failed to write cluster %#x", cluster);
+                       return -1;
+               }
                bufp += lsize;
                loffset = 0;
                remainder -= lsize;