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| author | Etienne Dublé <etienne.duble@imag.fr> | 2020-09-20 20:08:15 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2020-09-20 19:08:15 +0100 |
| commit | ba3b225a126ebb3c6d4fe27c9f7c73aa4167001e (patch) | |
| tree | 19149b92c169f419778e5e9799054b0c52243150 | |
| parent | 5b901ee0315658035661332d6d85d8bfd8816b6b (diff) | |
| download | fuse-ba3b225a126ebb3c6d4fe27c9f7c73aa4167001e.tar.gz | |
Allow caching symlinks in kernel page cache. (#551)
This commit defines a new capability called `FUSE_CAP_CACHE_SYMLINKS`.
It is off by default but you can now enable it by setting this flag in
in the `want` field of the `fuse_conn_info` structure.
When enabled, the kernel will save symlinks in its page cache,
by making use of the feature introduced in kernel 4.20:
https://github.com/torvalds/linux/commit/5571f1e65486be025f73fa6aa30fb03725d362a2
| -rw-r--r-- | ChangeLog.rst | 2 | ||||
| -rw-r--r-- | example/printcap.c | 2 | ||||
| -rw-r--r-- | include/fuse_common.h | 13 | ||||
| -rw-r--r-- | lib/fuse_lowlevel.c | 4 |
4 files changed, 20 insertions, 1 deletions
diff --git a/ChangeLog.rst b/ChangeLog.rst index d176dfa..4cb1478 100644 --- a/ChangeLog.rst +++ b/ChangeLog.rst @@ -1,7 +1,7 @@ Unreleased Changes ================== -* (none so far) +* Add FUSE_CAP_CACHE_SYMLINKS: allow caching symlinks in kernel page cache. libfuse 3.9.4 (2020-08-09) ========================== diff --git a/example/printcap.c b/example/printcap.c index e0eb6b6..bf058f5 100644 --- a/example/printcap.c +++ b/example/printcap.c @@ -77,6 +77,8 @@ static void pc_init(void *userdata, printf("\tFUSE_CAP_PARALLEL_DIROPS\n"); if(conn->capable & FUSE_CAP_POSIX_ACL) printf("\tFUSE_CAP_POSIX_ACL\n"); + if(conn->capable & FUSE_CAP_CACHE_SYMLINKS) + printf("\tFUSE_CAP_CACHE_SYMLINKS\n"); if(conn->capable & FUSE_CAP_NO_OPENDIR_SUPPORT) printf("\tFUSE_CAP_NO_OPENDIR_SUPPORT\n"); if(conn->capable & FUSE_CAP_EXPLICIT_INVAL_DATA) diff --git a/include/fuse_common.h b/include/fuse_common.h index 39937d3..f5bfb6a 100644 --- a/include/fuse_common.h +++ b/include/fuse_common.h @@ -347,6 +347,19 @@ struct fuse_loop_config { #define FUSE_CAP_HANDLE_KILLPRIV (1 << 20) /** + * Indicates that the kernel supports caching symlinks in its page cache. + * + * When this feature is enabled, symlink targets are saved in the page cache. + * You can invalidate a cached link by calling: + * `fuse_lowlevel_notify_inval_inode(se, ino, 0, 0);` + * + * This feature is disabled by default. + * If the kernel supports it (>= 4.20), you can enable this feature by + * setting this flag in the `want` field of the `fuse_conn_info` structure. + */ +#define FUSE_CAP_CACHE_SYMLINKS (1 << 23) + +/** * Indicates support for zero-message opendirs. If this flag is set in * the `capable` field of the `fuse_conn_info` structure, then the filesystem * may return `ENOSYS` from the opendir() handler to indicate success. Further diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c index 21379c1..83510b3 100644 --- a/lib/fuse_lowlevel.c +++ b/lib/fuse_lowlevel.c @@ -1963,6 +1963,8 @@ void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg) se->conn.capable |= FUSE_CAP_POSIX_ACL; if (arg->flags & FUSE_HANDLE_KILLPRIV) se->conn.capable |= FUSE_CAP_HANDLE_KILLPRIV; + if (arg->flags & FUSE_CACHE_SYMLINKS) + se->conn.capable |= FUSE_CAP_CACHE_SYMLINKS; if (arg->flags & FUSE_NO_OPENDIR_SUPPORT) se->conn.capable |= FUSE_CAP_NO_OPENDIR_SUPPORT; if (arg->flags & FUSE_EXPLICIT_INVAL_DATA) @@ -2087,6 +2089,8 @@ void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg) outarg.flags |= FUSE_WRITEBACK_CACHE; if (se->conn.want & FUSE_CAP_POSIX_ACL) outarg.flags |= FUSE_POSIX_ACL; + if (se->conn.want & FUSE_CAP_CACHE_SYMLINKS) + outarg.flags |= FUSE_CACHE_SYMLINKS; if (se->conn.want & FUSE_CAP_EXPLICIT_INVAL_DATA) outarg.flags |= FUSE_EXPLICIT_INVAL_DATA; outarg.max_readahead = se->conn.max_readahead; |