database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-09-02 04:21:28 +03:00
Code Activity

Fix buffile.c error handling.

Browse Source 
Convert buffile.c error handling to use ereport.  This fixes cases where
I/O errors were indistinguishable from EOF or not reported.  Also remove
"%m" from error messages where errno would be bogus.  While we're
modifying those strings, add block numbers and short read byte counts
where appropriate.

Back-patch to all supported releases.

Reported-by: Amit Khandekar <amitdkhan.pg@gmail.com>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Ibrar Ahmed <ibrar.ahmad@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CA%2BhUKGJE04G%3D8TLK0DLypT_27D9dR8F1RQgNp0jK6qR0tZGWOw%40mail.gmail.com
This commit is contained in:
Thomas Munro
2020-06-16 13:50:56 +12:00
parent 4c5cf54314
commit 7897e3bb90
7 changed files with 88 additions and 110 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
src/backend/storage/file/buffile.c
View File

@@ -99,7 +99,7 @@ static BufFile *makeBufFile(File firstfile);
static void extendBufFile(BufFile *file);
static void BufFileLoadBuffer(BufFile *file);
static void BufFileDumpBuffer(BufFile *file);
static int BufFileFlush(BufFile *file);
static void BufFileFlush(BufFile *file);
static File MakeNewSharedSegment(BufFile *file, int segment);
/*
@@ -434,7 +434,14 @@ BufFileLoadBuffer(BufFile *file)
file->curOffset,
WAIT_EVENT_BUFFILE_READ);
if (file->nbytes < 0)
{
file->nbytes = 0;
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not read file \"%s\": %m",
FilePathName(thisfile))));
}
/* we choose not to advance curOffset here */
if (file->nbytes > 0)
@@ -490,7 +497,10 @@ BufFileDumpBuffer(BufFile *file)
file->curOffset,
WAIT_EVENT_BUFFILE_WRITE);
if (bytestowrite <= 0)
return; /* failed to write */
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not write to file \"%s\" : %m",
FilePathName(thisfile))));
file->curOffset += bytestowrite;
wpos += bytestowrite;
@@ -522,7 +532,8 @@ BufFileDumpBuffer(BufFile *file)
/*
* BufFileRead
*
* Like fread() except we assume 1-byte element size.
* Like fread() except we assume 1-byte element size and report I/O errors via
* ereport().
*/
size_t
BufFileRead(BufFile *file, void *ptr, size_t size)
@@ -530,12 +541,7 @@ BufFileRead(BufFile *file, void *ptr, size_t size)
size_t nread = 0;
size_t nthistime;
if (file->dirty)
{
if (BufFileFlush(file) != 0)
return 0; /* could not flush... */
Assert(!file->dirty);
}
BufFileFlush(file);
while (size > 0)
{
@@ -569,7 +575,8 @@ BufFileRead(BufFile *file, void *ptr, size_t size)
/*
* BufFileWrite
*
* Like fwrite() except we assume 1-byte element size.
* Like fwrite() except we assume 1-byte element size and report errors via
* ereport().
*/
size_t
BufFileWrite(BufFile *file, void *ptr, size_t size)
@@ -585,11 +592,7 @@ BufFileWrite(BufFile *file, void *ptr, size_t size)
{
/* Buffer full, dump it out */
if (file->dirty)
{
BufFileDumpBuffer(file);
if (file->dirty)
break; /* I/O error */
}
else
{
/* Hmm, went directly from reading to writing? */
@@ -621,19 +624,15 @@ BufFileWrite(BufFile *file, void *ptr, size_t size)
/*
* BufFileFlush
*
* Like fflush()
* Like fflush(), except that I/O errors are reported with ereport().
*/
static int
static void
BufFileFlush(BufFile *file)
{
if (file->dirty)
{
BufFileDumpBuffer(file);
if (file->dirty)
return EOF;
}
return 0;
Assert(!file->dirty);
}
/*
@@ -642,6 +641,7 @@ BufFileFlush(BufFile *file)
* Like fseek(), except that target position needs two values in order to
* work when logical filesize exceeds maximum value representable by off_t.
* We do not support relative seeks across more than that, however.
* I/O errors are reported by ereport().
*
* Result is 0 if OK, EOF if not. Logical position is not moved if an
* impossible seek is attempted.
@@ -699,8 +699,7 @@ BufFileSeek(BufFile *file, int fileno, off_t offset, int whence)
return 0;
}
/* Otherwise, must reposition buffer, so flush any dirty data */
if (BufFileFlush(file) != 0)
return EOF;
BufFileFlush(file);
/*
* At this point and no sooner, check for seek past last segment. The