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libext2fs: force DIO alignment FreeBSD when operating on a block device
[tools/e2fsprogs.git] / lib / ext2fs / unix_io.c
index dd84271..85ad4e3 100644 (file)
@@ -15,6 +15,7 @@
  * %End-Header%
  */
 
+#if !defined(__FreeBSD__) && !defined(__NetBSD__) && !defined(__OpenBSD__)
 #define _XOPEN_SOURCE 600
 #define _DARWIN_C_SOURCE
 #define _FILE_OFFSET_BITS 64
@@ -27,6 +28,7 @@
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE
 #endif
+#endif
 
 #include "config.h"
 #include <stdio.h>
 #ifdef HAVE_SYS_MOUNT_H
 #include <sys/mount.h>
 #endif
+#ifdef HAVE_SYS_PRCTL_H
+#include <sys/prctl.h>
+#else
+#define PR_GET_DUMPABLE 3
+#endif
 #if HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif
@@ -101,8 +108,8 @@ struct unix_private_data {
        struct struct_io_stats io_stats;
 };
 
-#define IS_ALIGNED(n, align) ((((unsigned long) n) & \
-                              ((unsigned long) ((align)-1))) == 0)
+#define IS_ALIGNED(n, align) ((((uintptr_t) n) & \
+                              ((uintptr_t) ((align)-1))) == 0)
 
 static errcode_t unix_get_stats(io_channel channel, io_stats *stats)
 {
@@ -120,6 +127,29 @@ static errcode_t unix_get_stats(io_channel channel, io_stats *stats)
        return retval;
 }
 
+static char *safe_getenv(const char *arg)
+{
+       if ((getuid() != geteuid()) || (getgid() != getegid()))
+               return NULL;
+#ifdef HAVE_PRCTL
+       if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
+               return NULL;
+#else
+#if (defined(linux) && defined(SYS_prctl))
+       if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
+               return NULL;
+#endif
+#endif
+
+#if defined(HAVE_SECURE_GETENV)
+       return secure_getenv(arg);
+#elif defined(HAVE___SECURE_GETENV)
+       return __secure_getenv(arg);
+#else
+       return getenv(arg);
+#endif
+}
+
 /*
  * Here are the raw I/O functions
  */
@@ -133,11 +163,20 @@ static errcode_t raw_read_blk(io_channel channel,
        ext2_loff_t     location;
        int             actual = 0;
        unsigned char   *buf = bufv;
+       ssize_t         really_read = 0;
 
        size = (count < 0) ? -count : count * channel->block_size;
        data->io_stats.bytes_read += size;
        location = ((ext2_loff_t) block * channel->block_size) + data->offset;
 
+       if (data->flags & IO_FLAG_FORCE_BOUNCE) {
+               if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
+                       retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
+                       goto error_out;
+               }
+               goto bounce_read;
+       }
+
 #ifdef HAVE_PREAD64
        /* Try an aligned pread */
        if ((channel->align == 0) ||
@@ -186,14 +225,20 @@ static errcode_t raw_read_blk(io_channel channel,
         * The buffer or size which we're trying to read isn't aligned
         * to the O_DIRECT rules, so we need to do this the hard way...
         */
+bounce_read:
        while (size > 0) {
                actual = read(data->dev, data->bounce, channel->block_size);
-               if (actual != channel->block_size)
+               if (actual != channel->block_size) {
+                       actual = really_read;
+                       buf -= really_read;
+                       size += really_read;
                        goto short_read;
+               }
                actual = size;
                if (size > channel->block_size)
                        actual = channel->block_size;
                memcpy(buf, data->bounce, actual);
+               really_read += actual;
                size -= actual;
                buf += actual;
        }
@@ -230,6 +275,14 @@ static errcode_t raw_write_blk(io_channel channel,
 
        location = ((ext2_loff_t) block * channel->block_size) + data->offset;
 
+       if (data->flags & IO_FLAG_FORCE_BOUNCE) {
+               if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
+                       retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
+                       goto error_out;
+               }
+               goto bounce_write;
+       }
+
 #ifdef HAVE_PWRITE64
        /* Try an aligned pwrite */
        if ((channel->align == 0) ||
@@ -276,24 +329,34 @@ static errcode_t raw_write_blk(io_channel channel,
         * The buffer or size which we're trying to write isn't aligned
         * to the O_DIRECT rules, so we need to do this the hard way...
         */
+bounce_write:
        while (size > 0) {
                if (size < channel->block_size) {
                        actual = read(data->dev, data->bounce,
                                      channel->block_size);
                        if (actual != channel->block_size) {
-                               retval = EXT2_ET_SHORT_READ;
-                               goto error_out;
+                               if (actual < 0) {
+                                       retval = EXT2_ET_SHORT_READ;
+                                       goto error_out;
+                               }
+                               memset(data->bounce + actual, 0,
+                                      channel->block_size - actual);
                        }
                }
                actual = size;
                if (size > channel->block_size)
                        actual = channel->block_size;
                memcpy(data->bounce, buf, actual);
+               if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
+                       retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
+                       goto error_out;
+               }
                actual = write(data->dev, data->bounce, channel->block_size);
                if (actual != channel->block_size)
                        goto short_write;
                size -= actual;
                buf += actual;
+               location += actual;
        }
        return 0;
 
@@ -329,7 +392,7 @@ static errcode_t alloc_cache(io_channel channel,
                if (retval)
                        return retval;
        }
-       if (channel->align) {
+       if (channel->align || data->flags & IO_FLAG_FORCE_BOUNCE) {
                if (data->bounce)
                        ext2fs_free_mem(&data->bounce);
                retval = io_channel_alloc_buf(channel, 0, &data->bounce);
@@ -476,20 +539,22 @@ int ext2fs_fstat(int fd, ext2fs_struct_stat *buf)
 #endif
 }
 
-static errcode_t unix_open(const char *name, int flags, io_channel *channel)
+
+static errcode_t unix_open_channel(const char *name, int fd,
+                                  int flags, io_channel *channel,
+                                  io_manager io_mgr)
 {
        io_channel      io = NULL;
        struct unix_private_data *data = NULL;
        errcode_t       retval;
-       int             open_flags;
-       int             f_nocache = 0;
        ext2fs_struct_stat st;
 #ifdef __linux__
        struct          utsname ut;
 #endif
 
-       if (name == 0)
-               return EXT2_ET_BAD_DEVICE_NAME;
+       if (safe_getenv("UNIX_IO_FORCE_BOUNCE"))
+               flags |= IO_FLAG_FORCE_BOUNCE;
+
        retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io);
        if (retval)
                goto cleanup;
@@ -499,7 +564,7 @@ static errcode_t unix_open(const char *name, int flags, io_channel *channel)
        if (retval)
                goto cleanup;
 
-       io->manager = unix_io_manager;
+       io->manager = io_mgr;
        retval = ext2fs_get_mem(strlen(name)+1, &io->name);
        if (retval)
                goto cleanup;
@@ -514,35 +579,16 @@ static errcode_t unix_open(const char *name, int flags, io_channel *channel)
        memset(data, 0, sizeof(struct unix_private_data));
        data->magic = EXT2_ET_MAGIC_UNIX_IO_CHANNEL;
        data->io_stats.num_fields = 2;
-       data->dev = -1;
+       data->flags = flags;
+       data->dev = fd;
 
-       open_flags = (flags & IO_FLAG_RW) ? O_RDWR : O_RDONLY;
-       if (flags & IO_FLAG_EXCLUSIVE)
-               open_flags |= O_EXCL;
 #if defined(O_DIRECT)
-       if (flags & IO_FLAG_DIRECT_IO) {
-               open_flags |= O_DIRECT;
+       if (flags & IO_FLAG_DIRECT_IO)
                io->align = ext2fs_get_dio_alignment(data->dev);
-       }
 #elif defined(F_NOCACHE)
-       if (flags & IO_FLAG_DIRECT_IO) {
-               f_nocache = F_NOCACHE;
+       if (flags & IO_FLAG_DIRECT_IO)
                io->align = 4096;
-       }
 #endif
-       data->flags = flags;
-
-       data->dev = ext2fs_open_file(io->name, open_flags, 0);
-       if (data->dev < 0) {
-               retval = errno;
-               goto cleanup;
-       }
-       if (f_nocache) {
-               if (fcntl(data->dev, f_nocache, 1) < 0) {
-                       retval = errno;
-                       goto cleanup;
-               }
-       }
 
        /*
         * If the device is really a block device, then set the
@@ -551,7 +597,7 @@ static errcode_t unix_open(const char *name, int flags, io_channel *channel)
         * and if it succeed, subsequent read from sparse area returns
         * zero.
         */
-       if (ext2fs_stat(io->name, &st) == 0) {
+       if (ext2fs_fstat(data->dev, &st) == 0) {
                if (S_ISBLK(st.st_mode))
                        io->flags |= CHANNEL_FLAGS_BLOCK_DEVICE;
                else
@@ -567,7 +613,7 @@ static errcode_t unix_open(const char *name, int flags, io_channel *channel)
        }
 #endif
 
-#if defined(__CYGWIN__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+#if defined(__CYGWIN__)
        /*
         * Some operating systems require that the buffers be aligned,
         * regardless of O_DIRECT
@@ -576,6 +622,14 @@ static errcode_t unix_open(const char *name, int flags, io_channel *channel)
                io->align = 512;
 #endif
 
+#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+       if (io->flags & CHANNEL_FLAGS_BLOCK_DEVICE) {
+               int dio_align = ext2fs_get_dio_alignment(fd);
+
+               if (io->align < dio_align)
+                       io->align = dio_align;
+       }
+#endif
 
        if ((retval = alloc_cache(io, data)))
                goto cleanup;
@@ -614,7 +668,7 @@ static errcode_t unix_open(const char *name, int flags, io_channel *channel)
             (ut.release[2] == '4') && (ut.release[3] == '.') &&
             (ut.release[4] == '1') && (ut.release[5] >= '0') &&
             (ut.release[5] < '8')) &&
-           (ext2fs_stat(io->name, &st) == 0) &&
+           (ext2fs_fstat(data->dev, &st) == 0) &&
            (S_ISBLK(st.st_mode))) {
                struct rlimit   rlim;
 
@@ -647,6 +701,58 @@ cleanup:
        return retval;
 }
 
+static errcode_t unixfd_open(const char *str_fd, int flags,
+                            io_channel *channel)
+{
+       int fd;
+       int fd_flags;
+
+       fd = atoi(str_fd);
+       fd_flags = fcntl(fd, F_GETFD);
+       if (fd_flags == -1)
+               return -EBADF;
+
+       flags = 0;
+       if (fd_flags & O_RDWR)
+               flags |= IO_FLAG_RW;
+       if (fd_flags & O_EXCL)
+               flags |= IO_FLAG_EXCLUSIVE;
+#if defined(O_DIRECT)
+       if (fd_flags & O_DIRECT)
+               flags |= IO_FLAG_DIRECT_IO;
+#endif
+
+       return unix_open_channel(str_fd, fd, flags, channel, unixfd_io_manager);
+}
+
+static errcode_t unix_open(const char *name, int flags,
+                          io_channel *channel)
+{
+       int fd = -1;
+       int open_flags;
+
+       if (name == 0)
+               return EXT2_ET_BAD_DEVICE_NAME;
+
+       open_flags = (flags & IO_FLAG_RW) ? O_RDWR : O_RDONLY;
+       if (flags & IO_FLAG_EXCLUSIVE)
+               open_flags |= O_EXCL;
+#if defined(O_DIRECT)
+       if (flags & IO_FLAG_DIRECT_IO)
+               open_flags |= O_DIRECT;
+#endif
+       fd = ext2fs_open_file(name, open_flags, 0);
+       if (fd < 0)
+               return errno;
+#if defined(F_NOCACHE) && !defined(IO_DIRECT)
+       if (flags & IO_FLAG_DIRECT_IO) {
+               if (fcntl(fd, F_NOCACHE, 1) < 0)
+                       return errno;
+       }
+#endif
+       return unix_open_channel(name, fd, flags, channel, unix_io_manager);
+}
+
 static errcode_t unix_close(io_channel channel)
 {
        struct unix_private_data *data;
@@ -697,7 +803,6 @@ static errcode_t unix_set_blksize(io_channel channel, int blksize)
        return 0;
 }
 
-
 static errcode_t unix_read_blk64(io_channel channel, unsigned long long block,
                               int count, void *buf)
 {
@@ -846,8 +951,9 @@ static errcode_t unix_cache_readahead(io_channel channel,
        struct unix_private_data *data;
 
        data = (struct unix_private_data *)channel->private_data;
+       EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
        return posix_fadvise(data->dev,
-                            (ext2_loff_t)block * channel->block_size,
+                            (ext2_loff_t)block * channel->block_size + data->offset,
                             (ext2_loff_t)count * channel->block_size,
                             POSIX_FADV_WILLNEED);
 #else
@@ -960,7 +1066,7 @@ static errcode_t unix_discard(io_channel channel, unsigned long long block,
 #ifdef BLKDISCARD
                __u64 range[2];
 
-               range[0] = (__u64)(block) * channel->block_size;
+               range[0] = (__u64)(block) * channel->block_size + data->offset;
                range[1] = (__u64)(count) * channel->block_size;
 
                ret = ioctl(data->dev, BLKDISCARD, &range);
@@ -975,7 +1081,7 @@ static errcode_t unix_discard(io_channel channel, unsigned long long block,
                 */
                ret = fallocate(data->dev,
                                FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
-                               (off_t)(block) * channel->block_size,
+                               (off_t)(block) * channel->block_size + data->offset,
                                (off_t)(count) * channel->block_size);
 #else
                goto unimplemented;
@@ -1004,7 +1110,7 @@ static errcode_t unix_zeroout(io_channel channel, unsigned long long block,
        data = (struct unix_private_data *) channel->private_data;
        EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
 
-       if (getenv("UNIX_IO_NOZEROOUT"))
+       if (safe_getenv("UNIX_IO_NOZEROOUT"))
                goto unimplemented;
 
        if (channel->flags & CHANNEL_FLAGS_BLOCK_DEVICE) {
@@ -1012,29 +1118,30 @@ static errcode_t unix_zeroout(io_channel channel, unsigned long long block,
                goto unimplemented;
        } else {
                /* Regular file, try to use truncate/punch/zero. */
-#if defined(HAVE_FALLOCATE) && (defined(FALLOC_FL_ZERO_RANGE) || \
-       (defined(FALLOC_FL_PUNCH_HOLE) && defined(FALLOC_FL_KEEP_SIZE)))
                struct stat statbuf;
 
                if (count == 0)
                        return 0;
                /*
                 * If we're trying to zero a range past the end of the file,
-                * extend the file size, then punch (or zero_range) everything.
+                * extend the file size, then truncate everything.
                 */
                ret = fstat(data->dev, &statbuf);
                if (ret)
                        goto err;
-               if (statbuf.st_size < (block + count) * channel->block_size) {
+               if ((unsigned long long) statbuf.st_size <
+                       (block + count) * channel->block_size + data->offset) {
                        ret = ftruncate(data->dev,
-                                       (block + count) * channel->block_size);
+                                       (block + count) * channel->block_size + data->offset);
                        if (ret)
                                goto err;
                }
+#if defined(HAVE_FALLOCATE) && (defined(FALLOC_FL_ZERO_RANGE) || \
+       (defined(FALLOC_FL_PUNCH_HOLE) && defined(FALLOC_FL_KEEP_SIZE)))
 #if defined(FALLOC_FL_PUNCH_HOLE) && defined(FALLOC_FL_KEEP_SIZE)
                ret = fallocate(data->dev,
                                FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
-                               (off_t)(block) * channel->block_size,
+                               (off_t)(block) * channel->block_size + data->offset,
                                (off_t)(count) * channel->block_size);
                if (ret == 0)
                        goto err;
@@ -1042,7 +1149,7 @@ static errcode_t unix_zeroout(io_channel channel, unsigned long long block,
 #ifdef FALLOC_FL_ZERO_RANGE
                ret = fallocate(data->dev,
                                FALLOC_FL_ZERO_RANGE,
-                               (off_t)(block) * channel->block_size,
+                               (off_t)(block) * channel->block_size + data->offset,
                                (off_t)(count) * channel->block_size);
 #endif
 #else
@@ -1081,3 +1188,24 @@ static struct struct_io_manager struct_unix_manager = {
 };
 
 io_manager unix_io_manager = &struct_unix_manager;
+
+static struct struct_io_manager struct_unixfd_manager = {
+       .magic          = EXT2_ET_MAGIC_IO_MANAGER,
+       .name           = "Unix fd I/O Manager",
+       .open           = unixfd_open,
+       .close          = unix_close,
+       .set_blksize    = unix_set_blksize,
+       .read_blk       = unix_read_blk,
+       .write_blk      = unix_write_blk,
+       .flush          = unix_flush,
+       .write_byte     = unix_write_byte,
+       .set_option     = unix_set_option,
+       .get_stats      = unix_get_stats,
+       .read_blk64     = unix_read_blk64,
+       .write_blk64    = unix_write_blk64,
+       .discard        = unix_discard,
+       .cache_readahead        = unix_cache_readahead,
+       .zeroout        = unix_zeroout,
+};
+
+io_manager unixfd_io_manager = &struct_unixfd_manager;