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| author | Andres Freund <andres@anarazel.de> | 2025-02-25 09:02:07 -0500 |
|---|---|---|
| committer | Andres Freund <andres@anarazel.de> | 2025-02-25 09:02:07 -0500 |
| commit | 37c87e63f9e1a2d76db54fedcdf91d3895d200a6 (patch) | |
| tree | 1289dd23f92391ef9ec5171b59f4ac76f2e14a02 /src/backend/access/transam/xlogutils.c | |
| parent | 32c393f9f1f148febcd741e7067e9537825587cc (diff) | |
| download | postgresql-37c87e63f9e1a2d76db54fedcdf91d3895d200a6.tar.gz postgresql-37c87e63f9e1a2d76db54fedcdf91d3895d200a6.zip | |
Change relpath() et al to return path by value
For AIO, and also some other recent patches, we need the ability to call
relpath() in a critical section. Until now that was not feasible, as it
allocated memory.
The fact that relpath() allocated memory also made it awkward to use in log
messages because we had to take care to free the memory afterwards. Which we
e.g. didn't do for when zeroing out an invalid buffer.
We discussed other solutions, e.g. filling a pre-allocated buffer that's
passed to relpath(), but they all came with plenty downsides or were larger
projects. The easiest fix seems to be to make relpath() return the path by
value.
To be able to return the path by value we need to determine the maximum length
of a relation path. This patch adds a long #define that computes the exact
maximum, which is verified to be correct in a regression test.
As this change the signature of relpath(), extensions using it will need to
adapt their code. We discussed leaving a backward-compat shim in place, but
decided it's not worth it given the use of relpath() doesn't seem widespread.
Discussion: https://postgr.es/m/xeri5mla4b5syjd5a25nok5iez2kr3bm26j2qn4u7okzof2bmf@kwdh2vf7npra
Diffstat (limited to 'src/backend/access/transam/xlogutils.c')
| -rw-r--r-- | src/backend/access/transam/xlogutils.c | 29 |
1 files changed, 9 insertions, 20 deletions
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c index 68d53815925..b61a0eb4014 100644 --- a/src/backend/access/transam/xlogutils.c +++ b/src/backend/access/transam/xlogutils.c @@ -86,15 +86,14 @@ static void report_invalid_page(int elevel, RelFileLocator locator, ForkNumber forkno, BlockNumber blkno, bool present) { - char *path = relpathperm(locator, forkno); + RelPathStr path = relpathperm(locator, forkno); if (present) elog(elevel, "page %u of relation %s is uninitialized", - blkno, path); + blkno, path.str); else elog(elevel, "page %u of relation %s does not exist", - blkno, path); - pfree(path); + blkno, path.str); } /* Log a reference to an invalid page */ @@ -180,14 +179,9 @@ forget_invalid_pages(RelFileLocator locator, ForkNumber forkno, hentry->key.forkno == forkno && hentry->key.blkno >= minblkno) { - if (message_level_is_interesting(DEBUG2)) - { - char *path = relpathperm(hentry->key.locator, forkno); - - elog(DEBUG2, "page %u of relation %s has been dropped", - hentry->key.blkno, path); - pfree(path); - } + elog(DEBUG2, "page %u of relation %s has been dropped", + hentry->key.blkno, + relpathperm(hentry->key.locator, forkno).str); if (hash_search(invalid_page_tab, &hentry->key, @@ -213,14 +207,9 @@ forget_invalid_pages_db(Oid dbid) { if (hentry->key.locator.dbOid == dbid) { - if (message_level_is_interesting(DEBUG2)) - { - char *path = relpathperm(hentry->key.locator, hentry->key.forkno); - - elog(DEBUG2, "page %u of relation %s has been dropped", - hentry->key.blkno, path); - pfree(path); - } + elog(DEBUG2, "page %u of relation %s has been dropped", + hentry->key.blkno, + relpathperm(hentry->key.locator, hentry->key.forkno).str); if (hash_search(invalid_page_tab, &hentry->key, |