ivank added the comment: I managed to reproduce this again, this time by corrupting data on a btrfs filesystem.
$ cat read_error_file.py import os fname = "/usr/bin/Xorg" size = os.stat(fname).st_size print fname, "stat size:", size f = open(fname, "rb") print "len(f.read()): ", len(f.read()) f.close() f = open(fname, "rb") for i in xrange(size): try: f.read(1) except IOError: print "IOError at byte %d" % i break f.close() $ python read_error_file.py /usr/bin/Xorg stat size: 2331776 len(f.read()): 716800 IOError at byte 716800 Note how the first test does not throw an IOError, but the second one does. The strace for the first test is: open("/usr/bin/Xorg", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0755, st_size=2331776, ...}) = 0 fstat(3, {st_mode=S_IFREG|0755, st_size=2331776, ...}) = 0 lseek(3, 0, SEEK_CUR) = 0 fstat(3, {st_mode=S_IFREG|0755, st_size=2331776, ...}) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f1334bd6000 lseek(3, 0, SEEK_CUR) = 0 mmap(NULL, 2334720, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f1332ea6000 read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\265M\4\0\0\0\0\0"..., 2330624) = 716800 read(3, 0x7f1332f55034, 1613824) = -1 EIO (Input/output error) mremap(0x7f1332ea6000, 2334720, 720896, MREMAP_MAYMOVE) = 0x7f1332ea6000 munmap(0x7f1332ea6000, 720896) = 0 write(1, "len(f.read()): 716800\n", 23len(f.read()): 716800 ) = 23 Note the "-1 EIO (Input/output error)" that gets ignored somewhere. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue21090> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com