diff options
Diffstat (limited to 'src/backend/storage/file/fd.c')
| -rw-r--r-- | src/backend/storage/file/fd.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c index a280a1e7be3..277a28fc137 100644 --- a/src/backend/storage/file/fd.c +++ b/src/backend/storage/file/fd.c @@ -98,7 +98,9 @@ #include "storage/fd.h" #include "storage/ipc.h" #include "utils/guc.h" +#include "utils/guc_hooks.h" #include "utils/resowner_private.h" +#include "utils/varlena.h" /* Define PG_FLUSH_DATA_WORKS if we have an implementation for pg_flush_data */ #if defined(HAVE_SYNC_FILE_RANGE) @@ -162,6 +164,9 @@ bool data_sync_retry = false; /* How SyncDataDirectory() should do its job. */ int recovery_init_sync_method = RECOVERY_INIT_SYNC_METHOD_FSYNC; +/* Which kinds of files should be opened with PG_O_DIRECT. */ +int io_direct_flags; + /* Debugging.... */ #ifdef FDDEBUG @@ -2022,6 +2027,9 @@ FileWriteback(File file, off_t offset, off_t nbytes, uint32 wait_event_info) if (nbytes <= 0) return; + if (VfdCache[file].fileFlags & PG_O_DIRECT) + return; + returnCode = FileAccess(file); if (returnCode < 0) return; @@ -3826,3 +3834,93 @@ data_sync_elevel(int elevel) { return data_sync_retry ? elevel : PANIC; } + +bool +check_io_direct(char **newval, void **extra, GucSource source) +{ + bool result = true; + int flags; + +#if PG_O_DIRECT == 0 + if (strcmp(*newval, "") != 0) + { + GUC_check_errdetail("io_direct is not supported on this platform."); + result = false; + } + flags = 0; +#else + List *elemlist; + ListCell *l; + char *rawstring; + + /* Need a modifiable copy of string */ + rawstring = pstrdup(*newval); + + if (!SplitGUCList(rawstring, ',', &elemlist)) + { + GUC_check_errdetail("invalid list syntax in parameter \"%s\"", + "io_direct"); + pfree(rawstring); + list_free(elemlist); + return false; + } + + flags = 0; + foreach(l, elemlist) + { + char *item = (char *) lfirst(l); + + if (pg_strcasecmp(item, "data") == 0) + flags |= IO_DIRECT_DATA; + else if (pg_strcasecmp(item, "wal") == 0) + flags |= IO_DIRECT_WAL; + else if (pg_strcasecmp(item, "wal_init") == 0) + flags |= IO_DIRECT_WAL_INIT; + else + { + GUC_check_errdetail("invalid option \"%s\"", item); + result = false; + break; + } + } + + /* + * It's possible to configure block sizes smaller than our assumed I/O + * alignment size, which could result in invalid I/O requests. + */ +#if XLOG_BLCKSZ < PG_IO_ALIGN_SIZE + if (result && (flags & (IO_DIRECT_WAL | IO_DIRECT_WAL_INIT))) + { + GUC_check_errdetail("io_direct is not supported for WAL because XLOG_BLCKSZ is too small"); + result = false; + } +#endif +#if BLCKSZ < PG_IO_ALIGN_SIZE + if (result && (flags & IO_DIRECT_DATA)) + { + GUC_check_errdetail("io_direct is not supported for data because BLCKSZ is too small"); + result = false; + } +#endif + + pfree(rawstring); + list_free(elemlist); +#endif + + if (!result) + return result; + + /* Save the flags in *extra, for use by assign_io_direct */ + *extra = guc_malloc(ERROR, sizeof(int)); + *((int *) *extra) = flags; + + return result; +} + +extern void +assign_io_direct(const char *newval, void *extra) +{ + int *flags = (int *) extra; + + io_direct_flags = *flags; +} |