As Al Viro said:
we are getting well-meaning folks who try to check that return value,
again and again, getting it wrong every time. Typical idiocies:
* return some kind of error out of ->show() on overflows. Pointless
*and* wrong - only hard errors (== fail read(2) with that) should be
reported that way; the caller does detect overflow and retires with bigger
buffer just fine.
* keep checking it after every sodding call of seq_...(), screwing
the cleanups up more often than not. Pointless, unless you are doing some
seriously expensive calculations to produce something you are going to print.
seq_...() are no-ops in case when overflow has already happened.
seq_has_overflowed() is only for situations when you really want to skip
a serious amount of work generating the data that would end up being
discarded and recalculated again when the caller grabs a bigger buffer and
calls you again. And more often than not it's an indication of ->show()
trying to do the work of iterator - e.g. when you have single_open() with
->show() printing the entire hash table of some sort all in one record.
Most of the time checking return value of seq_...() is better replaced with
not doing that. And "must check return value and Do Something(tm)" is too
strong habit for enough people to cause recurring trouble.
Joe Perches (27):
staging: lustre: Convert "return seq_printf(...)" uses
staging: lustre: Convert seq_ hash functions to return void
staging: lustre: Convert uses of "int rc = seq_printf(...)"
staging: lustre: Convert remaining uses of "= seq_printf(...)"
x86: mtrr: if: Remove use of seq_printf return value
power: wakeup: Remove use of seq_printf return value
ipmi: Remove use of seq_printf return value
rtc: Remove use of seq_printf return value
ipc: Remove use of seq_printf return value
pxa27x_udc: Remove use of seq_printf return value
microblaze: mb: Remove use of seq_printf return value
nios2: cpuinfo: Remove use of seq_printf return value
ARM: plat-pxa: Remove use of seq_printf return value
openrisc: Remove use of seq_printf return value
cris: Remove use of seq_printf return value
mfd: ab8500-debugfs: Remove use of seq_printf return value
staging: i2o: Remove use of seq_printf return value
staging: rtl8192x: Remove use of seq_printf return value
s390: Remove use of seq_printf return value
i8k: Remove use of seq_printf return value
watchdog: bcm281xx: Remove use of seq_printf return value
proc: Remove use of seq_printf return value
cgroup: Remove use of seq_printf return value
tracing: Remove use of seq_printf return value
lru_cache: Remove use of seq_printf return value
parisc: Remove use of seq_printf return value
regulator: dbx500: Remove use of seq_puts/seq_printf return value
arch/arm/plat-pxa/dma.c | 111 ++++++------
arch/cris/arch-v10/kernel/setup.c | 58 +++---
arch/cris/arch-v32/kernel/setup.c | 62 +++----
arch/microblaze/kernel/cpu/mb.c | 149 ++++++++--------
arch/nios2/kernel/cpuinfo.c | 77 ++++----
arch/openrisc/kernel/setup.c | 50 +++---
arch/s390/pci/pci_debug.c | 6 +-
arch/x86/kernel/cpu/mtrr/if.c | 12 +-
drivers/base/power/wakeup.c | 16 +-
drivers/char/i8k.c | 16 +-
drivers/char/ipmi/ipmi_msghandler.c | 12 +-
drivers/char/ipmi/ipmi_si_intf.c | 26 +--
drivers/char/ipmi/ipmi_ssif.c | 4 +-
drivers/mfd/ab8500-debugfs.c | 196 +++++++++++++--------
drivers/parisc/ccio-dma.c | 54 +++---
drivers/parisc/sba_iommu.c | 86 +++++----
drivers/regulator/dbx500-prcmu.c | 32 +---
drivers/rtc/rtc-cmos.c | 36 ++--
drivers/rtc/rtc-ds1305.c | 6 +-
drivers/rtc/rtc-mrst.c | 16 +-
drivers/rtc/rtc-tegra.c | 4 +-
drivers/s390/cio/blacklist.c | 12 +-
drivers/staging/i2o/i2o_proc.c | 18 +-
.../lustre/include/linux/libcfs/libcfs_hash.h | 4 +-
drivers/staging/lustre/lustre/fid/lproc_fid.c | 23 ++-
drivers/staging/lustre/lustre/libcfs/hash.c | 13 +-
drivers/staging/lustre/lustre/llite/lproc_llite.c | 117 ++++++------
drivers/staging/lustre/lustre/lmv/lproc_lmv.c | 18 +-
drivers/staging/lustre/lustre/lov/lproc_lov.c | 30 ++--
drivers/staging/lustre/lustre/mdc/lproc_mdc.c | 6 +-
.../lustre/lustre/obdclass/linux/linux-module.c | 38 ++--
.../lustre/lustre/obdclass/lprocfs_status.c | 108 ++++++------
drivers/staging/lustre/lustre/obdclass/lu_object.c | 25 +--
drivers/staging/lustre/lustre/osc/lproc_osc.c | 67 +++----
.../staging/lustre/lustre/ptlrpc/lproc_ptlrpc.c | 25 +--
drivers/staging/lustre/lustre/ptlrpc/sec_bulk.c | 82 +++++----
drivers/staging/rtl8192e/rtllib_module.c | 4 +-
.../staging/rtl8192u/ieee80211/ieee80211_module.c | 4 +-
drivers/usb/gadget/udc/pxa27x_udc.c | 132 +++++++-------
drivers/watchdog/bcm_kona_wdt.c | 27 +--
fs/proc/array.c | 4 +-
fs/proc/base.c | 82 +++++----
ipc/msg.c | 34 ++--
ipc/sem.c | 26 +--
ipc/shm.c | 42 ++---
ipc/util.c | 6 +-
kernel/cgroup.c | 4 +-
kernel/trace/trace_stack.c | 4 +-
lib/lru_cache.c | 9 +-
49 files changed, 1050 insertions(+), 943 deletions(-)
--
2.1.2
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