Offline btrfs tools, like btrfs-image, will infinitely loop when there
is missing device.
The reason is, for missing device, it's fd will be set to -1, but before
we reading, we only check the fd validation by checking if it's 0.
So in that case, -1 will pass the validation check, and cause pread to
return 0, and loop to read.
Just change the validation check from "== 0" to "<= 0" to avoid such
problem.
Reported-by: Timothy Normand Miller <theosib@xxxxxxxxx>
Signed-off-by: Qu Wenruo <quwenruo@xxxxxxxxxxxxxx>
---
btrfs-image.c | 2 +-
disk-io.c | 4 ++--
extent_io.c | 4 ++--
3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/btrfs-image.c b/btrfs-image.c
index 3684a05..b225325 100644
--- a/btrfs-image.c
+++ b/btrfs-image.c
@@ -894,7 +894,7 @@ static int read_data_extent(struct metadump_struct *md,
device = multi->stripes[0].dev;
- if (device->fd == 0) {
+ if (device->fd <= 0) {
fprintf(stderr,
"Device we need to read from is not open\n");
free(multi);
diff --git a/disk-io.c b/disk-io.c
index fdcfd6d..d8ca101 100644
--- a/disk-io.c
+++ b/disk-io.c
@@ -266,7 +266,7 @@ int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirr
}
device = multi->stripes[0].dev;
- if (device->fd == 0) {
+ if (device->fd <= 0) {
kfree(multi);
return -EIO;
}
@@ -385,7 +385,7 @@ int read_extent_data(struct btrfs_root *root, char *data,
}
device = multi->stripes[0].dev;
- if (device->fd == 0)
+ if (device->fd <= 0)
goto err;
if (*len > max_len)
*len = max_len;
diff --git a/extent_io.c b/extent_io.c
index 5d49710..07695ef 100644
--- a/extent_io.c
+++ b/extent_io.c
@@ -714,7 +714,7 @@ int read_data_from_disk(struct btrfs_fs_info *info, void *buf, u64 offset,
device = multi->stripes[0].dev;
read_len = min(bytes_left, read_len);
- if (device->fd == 0) {
+ if (device->fd <= 0) {
kfree(multi);
return -EIO;
}
@@ -790,7 +790,7 @@ int write_data_to_disk(struct btrfs_fs_info *info, void *buf, u64 offset,
raid_map = NULL;
} else while (dev_nr < multi->num_stripes) {
device = multi->stripes[dev_nr].dev;
- if (device->fd == 0) {
+ if (device->fd <= 0) {
kfree(multi);
return -EIO;
}
--
2.5.0
--
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