From 274d46e1d35af423d0292d63c4d0ad7a03be82ba Mon Sep 17 00:00:00 2001 From: Phillip Susi Date: Thu, 24 Jan 2013 11:21:56 -0500 Subject: [PATCH] libext2fs: fix ext2fs_llseek on i386 ext2fs_llseek() was using lseek instead of lseek64. The only time it would use lseek64 is if passed an offset that overflowed 32 bits. This works for SEEK_SET, but not SEEK_CUR, which can apply a small offset to move the file pointer past the 32 bit limit. The code has been changed to instead try lseek64 first, and fall back to lseek if that fails. It also was doing a runtime check of the size of off_t. This has been moved to compile time. This fixes a problem which would cause e2image when built for x86-32 to bomb out when used with large file systems. Signed-off-by: Phillip Susi Signed-off-by: "Theodore Ts'o" --- configure.in | 3 +++ lib/config.h.in | 3 +++ lib/ext2fs/llseek.c | 18 ++++++++++-------- 3 files changed, 16 insertions(+), 8 deletions(-) diff --git a/configure.in b/configure.in index cf96e43c..c3687bb8 100644 --- a/configure.in +++ b/configure.in @@ -916,14 +916,17 @@ AC_CHECK_SIZEOF(short) AC_CHECK_SIZEOF(int) AC_CHECK_SIZEOF(long) AC_CHECK_SIZEOF(long long) +AC_CHECK_SIZEOF(off_t) SIZEOF_SHORT=$ac_cv_sizeof_short SIZEOF_INT=$ac_cv_sizeof_int SIZEOF_LONG=$ac_cv_sizeof_long SIZEOF_LONG_LONG=$ac_cv_sizeof_long_long +SIZEOF_OFF_T=$ac_cv_sizeof_off_t AC_SUBST(SIZEOF_SHORT) AC_SUBST(SIZEOF_INT) AC_SUBST(SIZEOF_LONG) AC_SUBST(SIZEOF_LONG_LONG) +AC_SUBST(SIZEOF_OFF_T) AC_C_BIGENDIAN BUILD_CC="$BUILD_CC" CPP="$CPP" /bin/sh $ac_aux_dir/parse-types.sh ASM_TYPES_HEADER=./asm_types.h diff --git a/lib/config.h.in b/lib/config.h.in index 90e97432..e14eff4f 100644 --- a/lib/config.h.in +++ b/lib/config.h.in @@ -543,6 +543,9 @@ /* The size of `long long', as computed by sizeof. */ #undef SIZEOF_LONG_LONG +/* The size of `off_t', as computed by sizeof. */ +#undef SIZEOF_OFF_T + /* The size of `short', as computed by sizeof. */ #undef SIZEOF_SHORT diff --git a/lib/ext2fs/llseek.c b/lib/ext2fs/llseek.c index b0576e40..c3a98a2c 100644 --- a/lib/ext2fs/llseek.c +++ b/lib/ext2fs/llseek.c @@ -90,17 +90,14 @@ static ext2_loff_t my_llseek (int fd, ext2_loff_t offset, int origin) ext2_loff_t ext2fs_llseek (int fd, ext2_loff_t offset, int origin) { +#if SIZEOF_OFF_T >= SIZEOF_LONG_LONG + return lseek (fd, offset, origin); +#else ext2_loff_t result; static int do_compat = 0; - if ((sizeof(off_t) >= sizeof(ext2_loff_t)) || - (offset < ((ext2_loff_t) 1 << ((sizeof(off_t)*8) -1)))) - return lseek(fd, (off_t) offset, origin); - - if (do_compat) { - errno = EINVAL; - return -1; - } + if (do_compat) + goto fallback; result = my_llseek (fd, offset, origin); if (result == -1 && errno == ENOSYS) { @@ -109,9 +106,14 @@ ext2_loff_t ext2fs_llseek (int fd, ext2_loff_t offset, int origin) * which does not support the llseek system call */ do_compat++; + fallback: + if (offset < ((ext2_loff_t) 1 << ((sizeof(off_t)*8) -1))) + return lseek(fd, (off_t) offset, origin); errno = EINVAL; + return -1; } return result; +#endif } #else /* !linux */ -- 2.11.0