| Message ID | 20210409155644.qkk6puelfjvtjwqs@fiona (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs-progs: Correct check_running_fs_exclop() return value | expand |
On 09/04/2021 23:56, Goldwyn Rodrigues wrote: > check_running_fs_exclop() can return 1 when exclop is changed to "none" > The ret is set by the return value of the select() operation. Checking > the exclusive op changes just the exclop variable while ret is still > set to 1. > > Set ret exclusively if exclop is set to BTRFS_EXCL_NONE. > --- SOB missing. > common/utils.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/common/utils.c b/common/utils.c > index 57e41432..2e5175c3 100644 > --- a/common/utils.c > +++ b/common/utils.c > @@ -2326,6 +2326,8 @@ int check_running_fs_exclop(int fd, enum exclusive_operation start, bool enqueue > tv.tv_sec /= 2; > ret = select(sysfs_fd + 1, NULL, NULL, &fds, &tv); > exclop = get_fs_exclop(fd); > + if (exclop == BTRFS_EXCL_NONE) > + ret = 0; > continue; > } > } > This is bit inconsistent from what is done a few lines above: exclop = get_fs_exclop(fd); if (exclop <= 0) { ret = 0; goto out; } We return 0 for both BTRFS_EXCLOP_NONE || BTRFS_EXCLOP_UNKNOWN. Thanks, Anand
On 6:50 10/04, Anand Jain wrote: > On 09/04/2021 23:56, Goldwyn Rodrigues wrote: > > check_running_fs_exclop() can return 1 when exclop is changed to "none" > > The ret is set by the return value of the select() operation. Checking > > the exclusive op changes just the exclop variable while ret is still > > set to 1. > > > > Set ret exclusively if exclop is set to BTRFS_EXCL_NONE. > > --- > > SOB missing. Yes, missed that. > > > common/utils.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/common/utils.c b/common/utils.c > > index 57e41432..2e5175c3 100644 > > --- a/common/utils.c > > +++ b/common/utils.c > > @@ -2326,6 +2326,8 @@ int check_running_fs_exclop(int fd, enum exclusive_operation start, bool enqueue > > tv.tv_sec /= 2; > > ret = select(sysfs_fd + 1, NULL, NULL, &fds, &tv); > > exclop = get_fs_exclop(fd); > > + if (exclop == BTRFS_EXCL_NONE) > > + ret = 0; > > continue; > > } > > } > > > > > This is bit inconsistent from what is done a few lines above: > > exclop = get_fs_exclop(fd); > if (exclop <= 0) { > ret = 0; > goto out; > } > > We return 0 for both BTRFS_EXCLOP_NONE || BTRFS_EXCLOP_UNKNOWN. > I am not sure why we are translating the sysfs file value to enums. The only status we are concerned about is with "none", anything besides that is considered to be busy, for code flow purposes. For error display, we can print whatever the sysfs file contains. Was this done for i18n? Of course, to maintain backward compatibility, we need to check on existence of the file. Anyways, I will re-post this patch with what is done a few lines above.
On Mon, Apr 12, 2021 at 10:56:41AM -0500, Goldwyn Rodrigues wrote: > On 6:50 10/04, Anand Jain wrote: > > On 09/04/2021 23:56, Goldwyn Rodrigues wrote: > > > check_running_fs_exclop() can return 1 when exclop is changed to "none" > > > The ret is set by the return value of the select() operation. Checking > > > the exclusive op changes just the exclop variable while ret is still > > > set to 1. > > > > > > Set ret exclusively if exclop is set to BTRFS_EXCL_NONE. > > > --- > > > > SOB missing. > > Yes, missed that. > > > > > > common/utils.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/common/utils.c b/common/utils.c > > > index 57e41432..2e5175c3 100644 > > > --- a/common/utils.c > > > +++ b/common/utils.c > > > @@ -2326,6 +2326,8 @@ int check_running_fs_exclop(int fd, enum exclusive_operation start, bool enqueue > > > tv.tv_sec /= 2; > > > ret = select(sysfs_fd + 1, NULL, NULL, &fds, &tv); > > > exclop = get_fs_exclop(fd); > > > + if (exclop == BTRFS_EXCL_NONE) > > > + ret = 0; > > > continue; > > > } > > > } > > > > > > > > > This is bit inconsistent from what is done a few lines above: > > > > exclop = get_fs_exclop(fd); > > if (exclop <= 0) { > > ret = 0; > > goto out; > > } > > > > We return 0 for both BTRFS_EXCLOP_NONE || BTRFS_EXCLOP_UNKNOWN. > > > > I am not sure why we are translating the sysfs file value to enums. The > only status we are concerned about is with "none", anything besides that > is considered to be busy, for code flow purposes. For error display, we > can print whatever the sysfs file contains. Was this done for i18n? No, I changed it to string to enum because this is separating the actual input from sysfs to the internal representation of a valid state. The original patch read the sysfs file and compared string everywhere, this is not a good practice. i18n is not done anywhere in progs so that's not the reason.
diff --git a/common/utils.c b/common/utils.c index 57e41432..2e5175c3 100644 --- a/common/utils.c +++ b/common/utils.c @@ -2326,6 +2326,8 @@ int check_running_fs_exclop(int fd, enum exclusive_operation start, bool enqueue tv.tv_sec /= 2; ret = select(sysfs_fd + 1, NULL, NULL, &fds, &tv); exclop = get_fs_exclop(fd); + if (exclop == BTRFS_EXCL_NONE) + ret = 0; continue; } }