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| author | Karel Zak | 2010-01-19 13:43:39 +0100 |
|---|---|---|
| committer | Karel Zak | 2010-01-19 14:48:22 +0100 |
| commit | d0465c3c00f75d7247cbbf02c1b3ff879c3f7bd3 (patch) | |
| tree | 53335a6354a654014c311b9faae12d03554f16c1 /shlibs/blkid/src/probe.c | |
| parent | libblkid: set minimal size for jfs, reiser, swap and zfs (diff) | |
| download | kernel-qcow2-util-linux-d0465c3c00f75d7247cbbf02c1b3ff879c3f7bd3.tar.gz kernel-qcow2-util-linux-d0465c3c00f75d7247cbbf02c1b3ff879c3f7bd3.tar.xz kernel-qcow2-util-linux-d0465c3c00f75d7247cbbf02c1b3ff879c3f7bd3.zip | |
libblkid: read whole SB buffer (69kB) on large disks
- on large disks read whole SB buffer
- new blkid_probe_is_tiny() version based on flags
Signed-off-by: Karel Zak <kzak@redhat.com>
Diffstat (limited to 'shlibs/blkid/src/probe.c')
| -rw-r--r-- | shlibs/blkid/src/probe.c | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/shlibs/blkid/src/probe.c b/shlibs/blkid/src/probe.c index b2c96a6b2..1bd98b55d 100644 --- a/shlibs/blkid/src/probe.c +++ b/shlibs/blkid/src/probe.c @@ -470,7 +470,7 @@ int __blkid_probe_filter_types(blkid_probe pr, int chain, int flag, char *names[ return 0; } -static int blkid_probe_has_buffer(blkid_probe pr, +int blkid_probe_has_buffer(blkid_probe pr, blkid_loff_t off, blkid_loff_t len) { return pr && (off + len <= pr->sbbuf_len || @@ -494,14 +494,20 @@ static unsigned char *blkid_probe_get_sb_buffer(blkid_probe pr, /* * The sbbuf is not completely in memory. * - * We don't read whole BLKID_SB_BUFSIZ by one read(), it's too - * aggresive to small devices (floppies). We read necessary - * data to complete the current request (off + len) only. */ ssize_t ret_read; - - blkid_loff_t have = pr->sbbuf_len, - want = off + len - have; + blkid_loff_t want, have = pr->sbbuf_len; + + if (blkid_probe_is_tiny(pr)) + /* We don't read whole BLKID_SB_BUFSIZ by one read(), + * it's too aggresive to small devices (floppies). We + * read necessary data to complete the current request + * (off + len) only. + */ + want = off + len - have; + else + /* large disk -- read all SB */ + want = BLKID_SB_BUFSIZ - have; DBG(DEBUG_LOWPROBE, printf("\tsb-buffer read() off=%jd len=%jd\n", have, want)); @@ -606,7 +612,7 @@ unsigned char *blkid_probe_get_buffer(blkid_probe pr, */ int blkid_probe_is_tiny(blkid_probe pr) { - return (pr && pr->size <= 1440 * 1024 && !S_ISCHR(pr->mode)); + return pr && (pr->flags & BLKID_TINY_DEV); } /** @@ -676,6 +682,10 @@ int blkid_probe_set_device(blkid_probe pr, int fd, goto err; DBG(DEBUG_LOWPROBE, printf("ready for low-probing, offset=%zd, size=%zd\n", pr->off, pr->size)); + + if (pr->size <= 1440 * 1024 && !S_ISCHR(pr->mode)) + pr->flags |= BLKID_TINY_DEV; + return 0; err: DBG(DEBUG_LOWPROBE, |