Check all lseek calls succeed.

Also add missing TEMP_FAILURE_RETRYs on read, write, and lseek.

Bug: http://b/20625546
Change-Id: I03b198e11c1921b35518ee2dd005a7cfcf4fd94b
(cherry picked from commit 7bad7c4646ee8fd8d6e6ed0ffd3ddbb0c1b41a2f)

3 files changed, 26 insertions, 38 deletions

diff --git a/mtdutils/flash_image.c b/mtdutils/flash_image.c
index 5657dfc..36ffa13 100644
--- a/mtdutils/flash_image.c
+++ b/mtdutils/flash_image.c
@@ -72,7 +72,7 @@ int main(int argc, char **argv) {
     if (fd < 0) die("error opening %s", argv[2]);
 
     char header[HEADER_SIZE];
-    int headerlen = read(fd, header, sizeof(header));
+    int headerlen = TEMP_FAILURE_RETRY(read(fd, header, sizeof(header)));
     if (headerlen <= 0) die("error reading %s header", argv[2]);
 
     MtdReadContext *in = mtd_read_partition(partition);
@@ -104,7 +104,7 @@ int main(int argc, char **argv) {
     if (wrote != headerlen) die("error writing %s", argv[1]);
 
     int len;
-    while ((len = read(fd, buf, sizeof(buf))) > 0) {
+    while ((len = TEMP_FAILURE_RETRY(read(fd, buf, sizeof(buf)))) > 0) {
         wrote = mtd_write_data(out, buf, len);
         if (wrote != len) die("error writing %s", argv[1]);
     }
@@ -125,13 +125,13 @@ int main(int argc, char **argv) {
     if (mtd_partition_info(partition, NULL, &block_size, NULL))
         die("error getting %s block size", argv[1]);
 
-    if (lseek(fd, headerlen, SEEK_SET) != headerlen)
+    if (TEMP_FAILURE_RETRY(lseek(fd, headerlen, SEEK_SET)) != headerlen)
         die("error rewinding %s", argv[2]);
 
     int left = block_size - headerlen;
     while (left < 0) left += block_size;
     while (left > 0) {
-        len = read(fd, buf, left > (int)sizeof(buf) ? (int)sizeof(buf) : left);
+        len = TEMP_FAILURE_RETRY(read(fd, buf, left > (int)sizeof(buf) ? (int)sizeof(buf) : left));
         if (len <= 0) die("error reading %s", argv[2]);
         if (mtd_write_data(out, buf, len) != len)
             die("error writing %s", argv[1]);
diff --git a/mtdutils/mtdutils.c b/mtdutils/mtdutils.c
index 9a17e38..cc30334 100644
--- a/mtdutils/mtdutils.c
+++ b/mtdutils/mtdutils.c
@@ -108,7 +108,7 @@ mtd_scan_partitions()
     if (fd < 0) {
         goto bail;
     }
-    nbytes = read(fd, buf, sizeof(buf) - 1);
+    nbytes = TEMP_FAILURE_RETRY(read(fd, buf, sizeof(buf) - 1));
     close(fd);
     if (nbytes < 0) {
         goto bail;
@@ -279,12 +279,6 @@ MtdReadContext *mtd_read_partition(const MtdPartition *partition)
     return ctx;
 }
 
-// Seeks to a location in the partition.  Don't mix with reads of
-// anything other than whole blocks; unpredictable things will result.
-void mtd_read_skip_to(const MtdReadContext* ctx, size_t offset) {
-    lseek64(ctx->fd, offset, SEEK_SET);
-}
-
 static int read_block(const MtdPartition *partition, int fd, char *data)
 {
     struct mtd_ecc_stats before, after;
@@ -293,13 +287,18 @@ static int read_block(const MtdPartition *partition, int fd, char *data)
         return -1;
     }
 
-    loff_t pos = lseek64(fd, 0, SEEK_CUR);
+    loff_t pos = TEMP_FAILURE_RETRY(lseek64(fd, 0, SEEK_CUR));
+    if (pos == -1) {
+        printf("mtd: read_block: couldn't SEEK_CUR: %s\n", strerror(errno));
+        return -1;
+    }
 
     ssize_t size = partition->erase_size;
     int mgbb;
 
     while (pos + size <= (int) partition->size) {
-        if (lseek64(fd, pos, SEEK_SET) != pos || read(fd, data, size) != size) {
+        if (TEMP_FAILURE_RETRY(lseek64(fd, pos, SEEK_SET)) != pos ||
+                    TEMP_FAILURE_RETRY(read(fd, data, size)) != size) {
             printf("mtd: read error at 0x%08llx (%s)\n",
                     pos, strerror(errno));
         } else if (ioctl(fd, ECCGETSTATS, &after)) {
@@ -409,8 +408,11 @@ static int write_block(MtdWriteContext *ctx, const char *data)
     const MtdPartition *partition = ctx->partition;
     int fd = ctx->fd;
 
-    off_t pos = lseek(fd, 0, SEEK_CUR);
-    if (pos == (off_t) -1) return 1;
+    off_t pos = TEMP_FAILURE_RETRY(lseek(fd, 0, SEEK_CUR));
+    if (pos == (off_t) -1) {
+        printf("mtd: write_block: couldn't SEEK_CUR: %s\n", strerror(errno));
+        return -1;
+    }
 
     ssize_t size = partition->erase_size;
     while (pos + size <= (int) partition->size) {
@@ -435,15 +437,15 @@ static int write_block(MtdWriteContext *ctx, const char *data)
                         pos, strerror(errno));
                 continue;
             }
-            if (lseek(fd, pos, SEEK_SET) != pos ||
-                write(fd, data, size) != size) {
+            if (TEMP_FAILURE_RETRY(lseek(fd, pos, SEEK_SET)) != pos ||
+                TEMP_FAILURE_RETRY(write(fd, data, size)) != size) {
                 printf("mtd: write error at 0x%08lx (%s)\n",
                         pos, strerror(errno));
             }
 
             char verify[size];
-            if (lseek(fd, pos, SEEK_SET) != pos ||
-                read(fd, verify, size) != size) {
+            if (TEMP_FAILURE_RETRY(lseek(fd, pos, SEEK_SET)) != pos ||
+                TEMP_FAILURE_RETRY(read(fd, verify, size)) != size) {
                 printf("mtd: re-read error at 0x%08lx (%s)\n",
                         pos, strerror(errno));
                 continue;
@@ -512,8 +514,11 @@ off_t mtd_erase_blocks(MtdWriteContext *ctx, int blocks)
         ctx->stored = 0;
     }
 
-    off_t pos = lseek(ctx->fd, 0, SEEK_CUR);
-    if ((off_t) pos == (off_t) -1) return pos;
+    off_t pos = TEMP_FAILURE_RETRY(lseek(ctx->fd, 0, SEEK_CUR));
+    if ((off_t) pos == (off_t) -1) {
+        printf("mtd_erase_blocks: couldn't SEEK_CUR: %s\n", strerror(errno));
+        return -1;
+    }
 
     const int total = (ctx->partition->size - pos) / ctx->partition->erase_size;
     if (blocks < 0) blocks = total;
@@ -554,18 +559,3 @@ int mtd_write_close(MtdWriteContext *ctx)
     free(ctx);
     return r;
 }
-
-/* Return the offset of the first good block at or after pos (which
- * might be pos itself).
- */
-off_t mtd_find_write_start(MtdWriteContext *ctx, off_t pos) {
-    int i;
-    for (i = 0; i < ctx->bad_block_count; ++i) {
-        if (ctx->bad_block_offsets[i] == pos) {
-            pos += ctx->partition->erase_size;
-        } else if (ctx->bad_block_offsets[i] > pos) {
-            return pos;
-        }
-    }
-    return pos;
-}
diff --git a/mtdutils/mtdutils.h b/mtdutils/mtdutils.h
index 2708c43..8059d6a 100644
--- a/mtdutils/mtdutils.h
+++ b/mtdutils/mtdutils.h
@@ -49,12 +49,10 @@ typedef struct MtdWriteContext MtdWriteContext;
 MtdReadContext *mtd_read_partition(const MtdPartition *);
 ssize_t mtd_read_data(MtdReadContext *, char *data, size_t data_len);
 void mtd_read_close(MtdReadContext *);
-void mtd_read_skip_to(const MtdReadContext *, size_t offset);
 
 MtdWriteContext *mtd_write_partition(const MtdPartition *);
 ssize_t mtd_write_data(MtdWriteContext *, const char *data, size_t data_len);
 off_t mtd_erase_blocks(MtdWriteContext *, int blocks);  /* 0 ok, -1 for all */
-off_t mtd_find_write_start(MtdWriteContext *ctx, off_t pos);
 int mtd_write_close(MtdWriteContext *);
 
 #ifdef __cplusplus